AudioCircle
Audio/Video Gear and Systems => Open Baffle Speakers => Topic started by: matevana on 28 Nov 2012, 02:43 pm
-
Inspired by the feel of the new Linkwitz LX-521 design, I began to work on a progression of the original Hestia project. Dubbed the Hestia-SL, in recognition of Siegfried Linkwitz's LX-521 main baffle shape.
(http://www.audiocircle.com/image.php?id=71503)
Initial Project design goals:
Continued use of the MCM Audio Select 10" lower midrange driver
Continued use of the Vifa D-19, or optional drop-in replacement of the XT-19 tweeter.
Introduction of a 5" coupling driver for enhanced mids
Incorporation of a H-Fame carrier for the LF driver with anti-vibration mount (or optional bridge)
All active or active/passive hybrid with a choice of 2, 3, or 4 way operation.
Floorstanding height with 5 degree incline: (42" H x 11.5" W x 15" D at widest point)
Alignment of all driver's acoustic centers
SL inspired main baffle shape for enhanced off-axis performance
Pleasing form-meets-function artistic design
Best bang-for-the-buck approach
At the present, the proposed driver selection includes:
Dayton Pro Sound 10" mid woofer
Vifa XT-19 dual ring radiator 3/4" driver (D-19 option)
Celestion 5" Neo Midrange (PE Buyout driver)
Usher 8955 8" bass driver in H-Frame
UPDATE: Here's a pic as of 12/21/12 with the 3rd baffle shape iteration.
(http://www.audiocircle.com/image.php?id=72671)
UPDATE: Fourth and final baffle revision 1/5/13:
(http://www.audiocircle.com/image.php?id=78879)
(http://www.audiocircle.com/image.php?id=73449)
Regards,
Ed
-
MCM Audio Seelect 10" mid woofer
Vifa XT-19 dual ring radiator 3/4" driver (D-19 option)
Celestion 5" Neo Midrange (PE Buyout driver)
Usher 8955 8" bass driver in H-Frame
Regards,
Ed
Hi Ed, unless you already have that driver, you could probably do a lot better for the $$. Not going to get much bass out of those in a dipole
cheers,
AJ
-
Looking forward to watching the project progress!
-
Hey AJ,
All of my designs use a single, smallish, articulate LF driver. It's that Allison Model One approach where sacrificing the lowest possible octave in hopes of achieving great sound in the upper bass, lower mid section can sometimes pay big dividends. I currently have a design that uses an Usher 8137a 8" woofer and the bass is solid down to the mid 50's in OB. More importantly to me, the 100-300 Hz range sounds right, which from a musician's standpoint gives the instruments their proper weight. This philosophy seems to be lacking in many of the OB designs I've heard, that try to makeup for this critical range by hitting the lowest register extra hard. The Ushers are also amazingly quiet in OB, with almost no motor noise or resonances.
Right now I'm testing a pair of the 8955's in stereo in their H-Frame carriers. Listening to them by themselves, I am convinced the bottom end will surprise many.
-
Looks nice. No rear tweeter, though? One of the main design goals of SL's new speaker is to maintain dipole directivity up to 7kHz. That obviously won't happen without two tweeters. Obviously you aren't trying to clone his design, so my comment is just an observation.
-
Looks nice. No rear tweeter, though? One of the main design goals of SL's new speaker is to maintain dipole directivity up to 7kHz. That obviously won't happen without two tweeters. Obviously you aren't trying to clone his design, so my comment is just an observation.
Yes, that's exactly right. The 5" midrange driver will cross to the tweeter in the area of 5-7k which is still to be determined, with mostly cardioid directivity above that. I personally experience more harm than good by running dipole beyond that, due to the less than ideal distance to the wall rear wall (about 30") in my listening room. Even in a more ideal space, I'm not sure I prefer dipole fullrange, but acknowledge that many do.
It's interesting when looking at the new designs from both SL and John K. that they are perhaps more similar than they are different. After decades of experimentation and refinement, both designers use similar driver and crossover topologies, baffle shape, width, etc. I find it reassuring when two of the neo-classical dipole guys have converged on common ideas. If you are going to borrow, why not borrow from some of the best. :)
-
I see that the Usher 8955 is no longer available at PE. Looks like it has been discontinued.
-
But of course there will soon be another Usher driver !
/Erling
-
Looks interesting. I may have misread but you would be running the H-frame up to 300 Hz?
-
I see that the Usher 8955 is no longer available at PE. Looks like it has been discontinued.
Hey SJ,
The 8955 is still current but unfortunately PE no longer carries them. Not to worry, the 8137a is still available and is just as quiet regarding mechanicals. A variety of 8" drivers with decent excursion will work. They should be able to be crossed as high as 150Hz and go down to around 40. The 8" servo sub from GR looks very interesting but I have not heard them.
-
Looks interesting. I may have misread but you would be running the H-frame up to 300 Hz?
The plan is to cross them no higher than 150Hz, and probably closer to 120. The 8" woofers seem to lend themselves to higher xo points if desirable in the overall design. Note that the 10" lower mid will partially overlap this driver and run from about 50Hz to the point where it meets the coupling midrange driver.
My comment earlier related to the critical region of 100-300 Hz, where you can feel the music in your gut. It is this area where I believe many of the OB designs are lacking. I spend a lot of time making sure this sounds the way it should. I do not use any active eq in my designs, instead relying on varying driver levels, crossover points and the occasional passive notch filters to compensate for dipole roll off.
-
Here's a few shots of the H-Frame Carriers I am testing. They are universal in design and will allow a variety of top baffles that attach with a unique shock mount. They are very compact measuring only 11.5" wide by about 15" deep at the widest point. They are built with a baffle incline of 5 degrees, and will hold the main baffle approximately 30 mm behind the woofer baffle to better align the driver's acoustic center and provide some time alignment as well.
(http://www.audiocircle.com/image.php?id=71701)
I am happy to say there is no baffle noise at near concert levels. The Ushers produce copious amounts of bass for their size and are extremely quiet, quieter than any OB bass driver I have used. This is true for both the 8955 shown in the picture as well as the 8137a kevlar bass driver. They are also very fast and articulate (return to zero). I have spent the entire day listening to the stereo pair of H-Frames, at varying crossover frequencies. They can be crossed much higher than typical, but the actual crossover point has yet to be determined.
(http://www.audiocircle.com/image.php?id=71703)
Materials used are full 1 inch thick poplar and 3/4" MDF. Panels are bolted with flex seal.
-
I am thinking about building the hestias and maybe trying the SLs as well in the new year
I live in the UK
What have folk found is the best way to buy the MCM and other drivers from the UK ?
I investigated on Amazon.com last night but it stopped me at the checkout
-
I am thinking about building the hestias and maybe trying the SLs as well in the new year
I live in the UK
What have folk found is the best way to buy the MCM and other drivers from the UK ?
I investigated on Amazon.com last night but it stopped me at the checkout
Hi Richard.
You should be able to purchase directly from MCM. Their site is www.mcmelectronics.com Not sure of their policy on international shipping but right now they are offering 15% off on most items. You have to use promo code AFC909 after the items are in your cart. I hope that helps! Let me know if you have any questions if you decide to build either Hestia project.
-
Hi Matevana
Looks nice. I like the circular sides. How is it all put together? The lower horizontal brace fastened to the sides and the bass baffle fastened to it and the upper panel fastened to the bass baffle? Are all three fastened to the sides? I think there are some pieces hiding between the bottom brace and the bass baffle and also between the bass baffle and the upper panel. No? Are they part of the vibration isolation design? Is flex seal that fabled audio vibration isolation product that I can also seal my gutters with as seen on tv?
You mentioned an active/passive setup. In the interest of estimating costs what sort of active parts are you considering? I assume as with the Hestia one option will be mono bass with a plate amp. Will the top end have an all passive setup?
-
Hi Matevana
Looks nice. I like the circular sides. How is it all put together? The lower horizontal brace fastened to the sides and the bass baffle fastened to it and the upper panel fastened to the bass baffle? Are all three fastened to the sides? I think there are some pieces hiding between the bottom brace and the bass baffle and also between the bass baffle and the upper panel. No? Are they part of the vibration isolation design? Is flex seal that fabled audio vibration isolation product that I can also seal my gutters with as seen on tv?
You mentioned an active/passive setup. In the interest of estimating costs what sort of active parts are you considering? I assume as with the Hestia one option will be mono bass with a plate amp. Will the top end have an all passive setup?
The H-carrier in the photo is assembled as a rigid unit. The shock mount isn't in the picture at this time, but will help to decouple the H-carrier from the main baffle which hasn't been built yet. The theory behind the shock mount is similar to the design of theater walls that are decoupled from the floor and ceiling. The hardware connecting the two will "float" so as not to transfer vibration from the H-Frame to the main baffle. I will post a more detailed drawing of this system when I can. The flex seal is an acoustic sealant that remains viscous and minimizes panel flex. It is used in conjunction with mechanical fasteners.
Most of my testing to date has been with an all active, tri-amped setup plus mono plate amp for the subs. I am learning a lot about what works and what doesn't. I'm not sure how easily this can be duplicated passively, but perhaps a hybrid might be the way to go, such as combining the lower mid with the mid, or the mid and tweeter. The other thing that's interesting, is that an all active system doesn't necessarily have to cost more, with high quality amplifier watts pricing out at about a dollar per watt (in the form of tripath amps used to drive the mids and highs). This can compare favorably to the rising cost of premium quality inductors, caps and resistors. Still lots of things to test, but it's coming along very nicely... if only I had more time to spend on the hobby :)
-
Here's a very rough sketch of the shock mount concept.
(http://www.audiocircle.com/image.php?id=71789)
Basically the main baffle is sandwiched to the H-frame carrier at three fulcrum points. The mechanical fasteners are only rigid where they come into contact with the main baffle. The pass through holes in the carrier are at least twice the diameter of the fasteners, so as not to come in direct contact with the hardware. The main baffle is suspended between two foam rubber donuts, about 1/4" thick. Vibrations traveling to the main baffle should be diminished.
(http://www.audiocircle.com/image.php?id=71790)
Here's a view from the side. The order from front to back would be lag bolt, main baffle, rubber donut, H-frame carrier, rubber donut, fender washer, lock nut. The baffle will be torqued just to the point where the rubber compresses and enough force is exerted to sandwich the baffle in place, but where the rubber rings still maintain their resiliency. Nylon inserts in the lock nut will prevent the nut from backing out over time. The rubber donuts or large o-rings will be made from foam rubber pipe insulation (tubes), sliced down to an appropriate thickness (approx 1/4" to 1/2").
-
Would this page be helpful?
http://www.amazon.com/Isolate-It-Sorbothane-Vibration-Isolation/dp/B0055SJEDG/ref=sr_1_fed0_14?ie=UTF8&qid=1354629061&sr=8-14&keywords=audio+isolator
-
Great catch! I currently use sorbathane pads as dampening feet, but have not seen isolators made from the same material. I may just order a set while I'm testing baffle designs.
On another note, I am beginning to appreciate the intricacies of incorporating a midrange driver into a design. It's not as easy as it seems and truly a balancing act. At this point I'm not too happy with the results, especially when I step back and compare it to a properly implemented 2.5 way design. And I'm prototyping with a 4th order active analog system where adjustments can be made in real time.
On the plus side, both tweeters (D19 and XT19) sound really nice when crossed low with a 4th order slope.
-
After 3 weeks of crossover development, the following is being presented as version 1.0. Most critical to the design is the mid level attenuation. Not being able to decide between more detailed/slightly forward and slightly less analytic, I decided to use a variable resistor (P1) to allow the listener to dial-in his/her preference, which may also depend on the source material.
The current driver/component combinations for version 1.0 are as follows:
Low/Mid:
Dayton 10" Pro Sound Driver 8 ohms
L1 = 1.80 mh
C1 = 30 uf
R1 = 8 ohms
Mid Coupler:
Celestion 5" Neo 8 ohms
L2 = .33 mh (18 ga)
C2 = 50 uf
P1 = 8 ohm potentiometer, 15 watts
High Frequency:
Vifa XT19TD00-04 4 ohms
C3 = 6.8 uf
R2 = 0.51 ohms
Note that the approximate crossover points are 700 Hz for the Low/Mid driver and 5800 Hz for the tweeter. The mid coupler crosses at approximately 400 Hz and 5700 Hz. The overlap/deficit is intentional and is used to help EQ the design. The drivers were chosen in part due to their low slope tolerance over the selected range.
The schematic is labeled version 1.0 for an important reason. The drivers are being tested on a rectangular temporary baffle and are not at their finished height. The actual completed baffle will also contour to help enhance off axis response. It is therefore anticipated that further adjustments to the component values will be necessary.
Also note that the Usher low bass driver is powered and crossed separately with a Yung plate amp, similar to the original Hestia design. The approximate x/o is 100 Hz.
(http://www.audiocircle.com/image.php?id=72377)
-
No, no, tell me it ain't so. Relegating my beloved (and cheap) MCM 55-2981 to a has been? So sad.
On another note I wonder about vibration from the low mid. I have quite a bit of baffle vibration on my Hestias. All three drivers are isolated from the 1 1/2" baffles with gasketing tape. The frames are relatively still but the baffles pick up a fair amount of vibration. Maybe it is the cumulative effect of the end of the dog's wagging tail but I feel most of it at the top adjacent to the mid. It appears to be originating from the mid. I wonder if further isolating the lower mid on the SLs might warrant a consideration. I'm sure I'm getting ahead of the design process once again, but I thought I might just mention it for consideration. I know vibration is a no-no. I don't know how much is acceptable.
This is not to criticize the Hestias which I think sound great.
-
No, no, tell me it ain't so. Relegating my beloved (and cheap) MCM 55-2981 to a has been? So sad.
On another note I wonder about vibration from the low mid. I have quite a bit of baffle vibration on my Hestias. All three drivers are isolated from the 1 1/2" baffles with gasketing tape. The frames are relatively still but the baffles pick up a fair amount of vibration. Maybe it is the cumulative effect of the end of the dog's wagging tail but I feel most of it at the top adjacent to the mid. It appears to be originating from the mid. I wonder if further isolating the lower mid on the SLs might warrant a consideration. I'm sure I'm getting ahead of the design process once again, but I thought I might just mention it for consideration. I know vibration is a no-no. I don't know how much is acceptable.
This is not to criticize the Hestias which I think sound great.
Hey Peter,
Yeah, it was difficult decision to make. The original Hestia's were designed to be more laid back and I couldn't be happier with the MCM's in that app. The Hestia-SL's are all about resolution and absolute detail; the MCM's just lose that lower mid clarity when crossed to the Celestion coupling driver.
Regarding vibration on your Hestias, I can think of a couple of things to try. First, your baffle dimensions are different, with greater open space between the upper and lower MCM drivers. That extra space could be acting as a bit of a sound board. If you believe it to be coming from the upper mid driver, try to limit it's excursion instead of allowing them to roll off naturally. An easy way to do this is with the use of a Harrison Labs FMOD inline crossover. (Parts Express) They are small passive inline RCA filters that go directly before your amp's inputs. You can try the ones that block frequencies below 100Hz. That will greatly eliminate the drivers moving mass up top, and hopefully make a big difference. Since your lower drivers are handling sub duties anyway, it may clean up the sound a bit from previously overlapping drivers.
Alternatively, if you are using an A/V receiver as your main amp, try working with it's internal crossover to roll-off the mid driver a bit in a similar manner.
Lastly, in looking at your photos, you may be able to deaden the aforementioned "sound board" area by bracing the top third of the baffle from the back. Those industrial c-channel shelving standards screwed in from the back into the meat of the baffle should do the trick. I'm specifically referring to the steel standards that accommodate double wide shelving brackets similar to what you might see in a garage. You can use a rubber gasket between the standards and the baffle back where they come in contact. Often a thinner baffle reinforced with c-channel will resonate less than a thicker baffle without. C-channel of this caliber will not warp over time and should hold the baffle taut.
-
interesting!!
what would be other alternatives for the 10" pro woofer? is this mandatory? i mean size and sens?
henry
-
interesting!!
what would be other alternatives for the 10" pro woofer? is this mandatory? i mean size and sens?
henry
The SL design relies on the careful matching of drivers and their efficiency, as there is no need for additional EQ or compensation. The larger than average 10" mid driver is needed to flesh-out the lower mids that would otherwise roll off due to cancellation, when used with a smaller than average LF driver, which too is part of the unique alignment of this design. Other pro sound drivers may work well, with an average sensitivity of around 95dB and a total Q approaching .5. Anything less and you will likely need to biamp (or even triamp) the design. The driver must also be well defined in the upper bass / lower mid range, or it will not properly mesh with the very articulate midrange coupling driver. The previously used MCM drivers excel in the lowest octaves, but can really lose coherence in the upper registers. This becomes more obvious when mated in a 3-way design.
-
matevana
Would that be the Dayton Audio PA255-8 10" Pro Woofer? The price isn't too bad.
I'll look into C channel on the back of the Hestias. That is a good idea.
-
matevana
Would that be the Dayton Audio PA255-8 10" Pro Woofer? The price isn't too bad.
I'll look into C channel on the back of the Hestias. That is a good idea.
You are correct sir! Not a bad driver for the money. Just wish it had that nice aluminum cast frame that the MCM sports.
-
(http://www.audiocircle.com/image.php?id=72669)
Lots of testing going on. The isolation mount seems to work well. Lots of component value swapping and critical listening. Test baffle dimensions in 3/4" MDF images well. This is now the 3rd baffle design and each have affected the off axis response primarily. The 3rd iteration appears to work best to date. I now have a new favorite tweeter, namely the VIFA XT19.
-
A closer pic showing baffle shape iteration #3, 12/21/12:
(http://www.audiocircle.com/image.php?id=72672)
-
And after another 20 hours of listening, it's on to baffle iteration #4. Since the Hestia-SL design doesn't use any active compensation for the top three drivers, the nude-like baffle around the mid just wasn't cutting it. A bit too much cancellation. A complete baffle redesign was necessary in order to provide more baffle "real estate" around the mid driver, while maintaining the desired imaging characteristics. In a mock-up made of Masonite, this baffle shape made a big difference. The actual baffle will be cut from 1" spruce. Since there isn't a lot of excess meat on the baffle, the driver's frames mounted with 1" screws will help keep the baffle rigid. I also noticed that softer/thicker woods actually do a nice job in absorbing certain resonances, despite what one might think.
A few more crossover component changes and it'll be about 90% there.
The original Hestia design to the left is being built for my neighbor. He actually spent a lot of time bringing CD's by to hear them. Every time he thought he could stump the design he just laughed, shook his head and went back to his $1500 pair of boxed speakers. He soon will have his own pair, at about one tenth the cost. :thumb:
(http://www.audiocircle.com/image.php?id=72926)
-
Huge progress in the past 24 hours. The extra baffle width was exactly what was needed. The results are quite measurable keeping all the other parameters in tact, even the exact baffle position relative to the rear wall, etc. as marked by the carpet tile. I also happen to prefer the aesthetics to the first 3 baffles tested. Next up are a few crossover tweaks where off axis measurements are concerned.
The spaghetti sitting behind the speaker consists of 28 test leads attached to caps, coils and resistors. Very easy to swap out components this way and hear subtle changes quickly. The finished crossover boards are currently being worked on as well.
(http://www.audiocircle.com/image.php?id=72940) ; (http://www.audiocircle.com/image.php?id=72956)
-
The final baffle has a pleasing shape to my eye.
That would be 5/4" spruce in dimensional terms? It looks to be 13" or more at the widest? Where did you find that? What kind of spruce and please don't tell me Sitka. Is the top baffle fairly vibration free?
I'll let you finish before I ask the question and I don't mean how much did it all cost.
You must be pleased. Looks like another well integrated design.
Peter
-
beautiful!
will you do some measurements?
-
The final baffle has a pleasing shape to my eye.
That would be 5/4" spruce in dimensional terms? It looks to be 13" or more at the widest? Where did you find that? What kind of spruce and please don't tell me Sitka. Is the top baffle fairly vibration free?
I'll let you finish before I ask the question and I don't mean how much did it all cost.
You must be pleased. Looks like another well integrated design.
Peter
Hey Peter,
Sitka??? Never! :lol: They are actually stain grade table tops sold at Lowes and come with nice roundovers on the edges. The baffles use the 24" round while the side panels are 15" round. They are 5/4" thickness and measure very close to 1" with a ruler. You are exactly right; 13" at the widest point, 7.5" at the bottom and 4" at the top. A total of 4 cuts with a circular saw and guide.
I use Google Sketch-up to lay out the baffle and drivers, then print a pattern in 1:1 size to be used as a template. Works very well with irregular shapes. Note that the top and bottom of the baffle maintain their original round profile, which adds a nice touch. The mid driver's cutout is chamfered in the back.
Vibrations are minimized by two factors. First, I'm using sorbothane material to "sandwich" the baffle to the mount and the fasteners (screws) sit in over sized holes so they don't directly contact the mount. Second is the fact that the drivers are spaced closely together and all the extraneous baffle material has been eliminated. Less material (of the same design) can translate to fewer resonance concerns.
I think you were also asking about the project cost. Well... not too shabby for the big sister of the Hestia. In keeping with the design mantra, I was able to build the SL's at a cost of under $200 per side for the all active version, including building materials. The passive version (the design I am working on now) will add another $50 or so for component costs, but will allow you to drive the top three drivers with something as small and inexpensive as a T-amp.
They measure out at around 90.5 dB efficiency with a system impedance of 7.8 ohms. They sound great with an SET amp as well. I am using two Yung plate amps on the SL version so the H-frames can be driven in stereo. This is not absolutely necessary but is recommended since a higher degree of imaging is sought. One could easily start with a single amp in mono and later upgrade as desired.
Baffle material & template:
(http://www.audiocircle.com/image.php?id=72985)
-
beautiful!
will you do some measurements?
Unfortunately my in-room measurement capabilities are limited to a digital SPL meter and 31 bands of test tones recorded at the same amplitude. At this time no single reading deviates by more than +/- 4 dB from a range of 50 Hz through 15k on axis. In tweaking the crossover design, I hope to improve upon that slightly.
That being said, let me rant a bit about one thing with all due respect to others. :green: I have heard speakers that are ruler flat that I would also describe as un-involving. As a musician I am perhaps more sensitive to the weight and timbre of various instruments than many. What drew me to OB initially is their ability to involve the listener, as cliche as that might sound. Pianos should not just sound good, but they should sound like pianos. If you close your eyes, you should be able to picture an 8' deep grand piano in the listening space, as opposed to a pleasant sounding recording of the same. A well executed OB design will do this. I guess my point is that much emphasis is placed on measurement which is certainly quantifiable. Perhaps as important is a speakers ability to draw you in. I'm sure many of the full-range driver enthusiasts will agree. While many of the psycho-acoustic properties are less quantifiable, and therefore harder to measure, there is also something to be said for designing for interpretation as a goal.
-
That being said, let me rant a bit about one thing with all due respect to others. :green: I have heard speakers that are ruler flat that I would also describe as un-involving. As a musician I am perhaps more sensitive to the weight and timbre of various instruments than many. What drew me to OB initially is their ability to involve the listener, as cliche as that might sound. Pianos should not just sound good, but they should sound like pianos. If you close your eyes, you should be able to picture an 8' deep grand piano in the listening space, as opposed to a pleasant sounding recording of the same. A well executed OB design will do this. I guess my point is that much emphasis is placed on measurement which is certainly quantifiable. Perhaps as important is a speakers ability to draw you in. I'm sure many of the full-range driver enthusiasts will agree. While many of the psycho-acoustic properties are less quantifiable, and therefore harder to measure, there is also something to be said for designing for interpretation as a goal.
I must say that I agree with this. I am a fairly experienced DIY loudspeaker builder but at the same time I have little experience in the measurement and frequency analysis department. For this very reason I have decided to up my game. My wife was kind enough to give me SoundEasy for Christmas. I am now in the process of setting up a small lab in my shop as well as a measurement bay in my back yard. I am going to learn to measure drivers as well as assembled speaker designs and analyze the response characteristics. I have been a mechanical design engineer for 30 some years and I am looking forward to finding out new and surprising developments through my own research. My tastes rarely parallel convention when it comes to design work whether it be loudspeakers or anything else I have designed.
-
I must say that I agree with this. I am a fairly experienced DIY loudspeaker builder but at the same time I have little experience in the measurement and frequency analysis department. For this very reason I have decided to up my game. My wife was kind enough to give me SoundEasy for Christmas. I am now in the process of setting up a small lab in my shop as well as a measurement bay in my back yard. I am going to learn to measure drivers as well as assembled speaker designs and analyze the response characteristics. I have been a mechanical design engineer for 30 some years and I am looking forward to finding out new and surprising developments through my own research. My tastes rarely parallel convention when it comes to design work whether it be loudspeakers or anything else I have designed.
Another member was nice enough to share similar comments via PM this afternoon. I wanted to echo a paragraph he wrote that I thought really nailed this sentiment (and stated more eloquently than I ever could):
"Couldn't agree more with your comments about measurements vs. involvement. I'm using a Lowther in a "no baffle" stand coupled to a transmission line bass. I'm positive it measures poorly and yet, everyone that has heard it scratches their head and says "there is no way that should sound so good". OB just loads a room in a more natural way to my band director/ trumpet player's ears. One advantage my weird system has is using active crossovers. Being able to adjust response around middle C lets me dial in cello and basses so they have enough body. I think you are saying the same thing about your designs having realistic body and involvement".
Again, I don't suggest disregarding measurements entirely; I think they can be very helpful in establishing a baseline, determining a driver's actual vs published T-S params, etc.. But I do think there is something to be said for fine tuning by ear once that standard is roughly attained. It's also helpful if that ear has the experience and ability to discern how instruments should sound, and help establish that emotional connection one gets when everything sounds just right, as subjective as that might be.
-
Hi I have been following this hestia sl build as well as some of your older ones. What Yung amps are you using? I am thinking of getting a pair before they go off sale at PE. I was thinking of a pair of the yung 300 or 200 but do you recommend the ones with 6db boost or not? I am leaning more toward a pair of the 200 with boost but want to know more from you before I order. Also are there any other options for the lower woofer? Thanks KEEP UP THE GOOD WORK! The table upper baffle looks AWESOME! I want a pair in my living room. :wink:
-
Hi I have been following this hestia sl build as well as some of your older ones. What Yung amps are you using? I am thinking of getting a pair before they go off sale at PE. I was thinking of a pair of the yung 300 or 200 but do you recommend the ones with 6db boost or not? I am leaning more toward a pair of the 200 with boost but want to know more from you before I order. Also are there any other options for the lower woofer? Thanks KEEP UP THE GOOD WORK! The table upper baffle looks AWESOME! I want a pair in my living room. :wink:
Hi and thanks for the feedback. I am using two of the 300 watt amps w/o boost. In my current setup, each amp drives one Usher 8955 bass driver @ 8 ohms, so realistically they put out around 175 watts. The amps are known to put out a true 300 watts when driving a 4 ohm load. Keep in mind these are class D amps so the distortion level is notably lower at 8 ohms then it is at 4. The damping factor appears to be higher at 8 ohms as well, which will likely benefit bass drivers with higher than average total Q (Qts), as is often the case with OB woofers.
I avoided the boost version thinking that 6 dB at 30 Hz will do little more than cause an 8" driver to go into over excursion. You will likely hit the drivers xmax at lower volume levels than the same amp would without boost. And since you cant defeat the boost feature easily, it's better to be safe than sorry. I can tell you that the quality and quantity of bass in the SL design is impressive.
I really like any of the 8" Usher drivers. I have the Usher 8137a in OB in my bedroom system and they are excellent as well. The 8" Ushers are quite resilient, fast and sound great IMO. Most important, the motors are extremely quiet. Try isolating other (sub)woofers in OB and you will often hear motor noise from the rear of the driver. To me this is very distracting and the Ushers don't seem to have this problem. Remember that most speaker manufacturers allow a certain amount of motor noise in their designs knowing that a well damped cabinet will absorb the bulk of it. This is not the case in OB.
I have also been impressed with some of the 8" designs from Aurum Cantus, SB Acoustics and Vifa. I am not sold on the Peerless 8" SLS woofer unless you consider multiples, and that may go for some of the Seas 8" drivers as well. I have not had good luck with Tang Band
in OB.
-
Here's a picture of the working crossover. I'm going to live with this for a bit before posting final component vales.
(http://www.audiocircle.com/image.php?id=73024)
-
Matevana,
I wonder how you would think about taking the new baffle theme one step further - by replacing the circular side baffles with the new edgy shape:
(http://www.audiocircle.com/image.php?id=73028)
The side wings would start at the widest point of the speaker baffle and narrow towards the bottom. This would give the whole thing an even lighter appearence.
Rudolf
-
Rudolf,
That's very creative and not a bad idea at all. For now I'm married to the uniqueness of the circular side panels, but the side panels and main baffle can be removed in minutes so future upgrades can be easy! I'll have to give it some thought. Thanks!
-
Hi Just wondering what your thoughts were of replacing the usher 8955a with the dayton audio RS225-8.
Is it close enough to use? It is certainly much more available and affordable. I can't myself accurately decifer from the spec sheets if they are close to each other or not. I just was looking up the ushers and found the daytons being spoken about for the same speaker design they were contemplating. Albeit they were not using either in ob. They seemed to give it favorable reviews. Let me know if it would work as a low cost alternative.
-
Hi Just wondering what your thoughts were of replacing the usher 8955a with the dayton audio RS225-8.
Is it close enough to use? It is certainly much more available and affordable. I can't myself accurately decifer from the spec sheets if they are close to each other or not. I just was looking up the ushers and found the daytons being spoken about for the same speaker design they were contemplating. Albeit they were not using either in ob. They seemed to give it favorable reviews. Let me know if it would work as a low cost alternative.
Neither the Ushers nor the RS225's have T-S parameters that are particularly well suited to OB. The Ushers just happen to work well in this design, mostly due to their low moving mass coupled with minimal motor noise. This translates into less baffle vibration and the potential for additional noise. Aside from this, it would be nice if their Qts was a little higher, and their excursion (xmax) a little longer. Both are reasonably efficient.
I haven't heard the Dayton RS225's but their parameters are fairly close to that of the 8955. You may also want to take a look at the Usher 8137a sold at PE. They are more money than the Daytons, but periodically go on sale. If you catch them on the DOTD (Deal of the day) you should grab two of them up. I got mine for $60 ea and they put out a surprising amount of quality bass for their size.
-
Completed a 2nd SL with the revised baffle shape. Things are settling in so crossover changes are now few and far between. I can say the design images well. The sound stage is taller than the original Hestia and it's easier to pin point an instruments width and depth on stage. Unlike the original Hestia which are a bit laid back, the SL's are very revealing which can be both good and bad. Good CD's sound great as do HD music files. That being said, lesser quality recordings are not "masked" as they are with the original design. In short, they are a highly resolving version of the originals.
(http://www.audiocircle.com/image.php?id=73444)
The circular side panels work very well within the context of the design. I knew I wanted an H-Frame but didn't want speakers that looked too heavy in the Living Room. They definitely appear less assuming than a cube of similar dimensions. I also feel like they don't photograph well. Those who have seen them in person comment that they are much more attractive then they are in pictures. I suppose this is true for some people as well. :lol:
-
Looking great :thumb:
Just curious about distance to the wall. Have you tried them further away?
-
Looking great :thumb:
Just curious about distance to the wall. Have you tried them further away?
At this point, all of my listening has been done with the back of the drivers 36" from the rear wall. The left speaker is also 50" from the side wall. Surprisingly there are few adverse reflections as most of the surfaces are hard. The room would be categorized as lively. The SL's each sit on a 12" x 10" carpet tile with jute backing. There is a 4' x 6' wool area rug about 6 feet in front of the SL's, centered between the two.
Bass response is plentiful, tight and articulate. Lower mids are exceptionally good. The Ushers sit 1" above floor level. All drivers are time aligned based on the location of their acoustic centers. Listening to fast acoustic bass runs, every inflection seems to be audible and does not lag. So far, so good.
-
an aesthetic suggestion:
you may cover the bass section with speaker cloth to make it look like a cylinder (leaving the circular wood panels exposed).
speakers on wheels... kind of look.
-
an aesthetic suggestion:
you may cover the bass section with speaker cloth to make it look like a cylinder (leaving the circular wood panels exposed).
speakers on wheels... kind of look.
LOL... at one point I toyed with the idea of allowing the side panels to turn freely, so they could be rolled away from the wall while listening and then rolled back against the wall when idle. Too much of a logistical issue with vibration, etc.
I really don't mind the exposed look of OB... kind of industrial. I even like the look of exposed wiring and the crossover components on the rear panel. I think it adds to the aesthetics. There's some pretty cool muscle car accessories that are designed to neatly route spark plug wires that can also be used to channel speaker wire down the back of an OB design. So many possibilities.
-
Here's a better perspective of the SL's in their listening room showing approximate distance to room boundaries.
(http://www.audiocircle.com/image.php?id=73715)
Wider view showing digital sever in adjoining room. I plan to get rid of my CD player entirely once all libraries have been converted to lossless files. In addition to my laptop setup which supports hi res music files, I also use an iPod classic with a pure digital tap that plays 16/44.1 files through a Schiit Bifrost DAC. Weighs a few ounces and holds 160GB of actual CD quality sound (About 4000 songs). The key to getting great sound from an iPod is tapping it's digital signal and bypassing the internal DAC with a good quality outboard DAC. In blind tests, I can not tell the difference between that and my CD player. The convenience and playlist capabilities far outweigh any CD player.
The chain looks something like this: (Toslink cable between Digital Dock and DAC)
iPod Classic -> Pure i-20 Digital Dock -> Schiit Bifrost DAC -> Crown D-75a Power Amp -> Hestia SL's
(http://www.audiocircle.com/image.php?id=73716)
-
I'm really impressed with the ability to extract bit perfect digital audio files from an iPod. My audio rig has been condensed to all of three components. The iPod sits on a Pure i-20 digital dock. The dock extracts pit perfect information from lossless files (ALAC) from the iPod in either 16 or 24 bit depths. The sample rate can be 44.1kHz (Redbook CD) or 48kHz (higher). The iPod will not support anything beyond that at this time, but the sound is equal to or better than "CD Quality".
The dock then passes the information to an external DAC (Schiit Bifrost) via optical cable, where its converted into an analog signal and fed to a Crown broadcast quality power amp. The iPod dock acts as a master volume control with full remote functionality... and not just cue and review, but playlists, genres, artists, multiple shuffle/repeat, etc... way more than typical CD functionality. And unlike Windows based media servers, the iPod does one thing so all of its processing power is focused on music, which helps to reduce jitter.
The crown power amp feeds the top three drivers on the Hestia SL's. The headphone out serves as a variable line out and drives a pair of Yung plate amps for the lower drivers. Everything stays nice and balanced when the volume is increased or decreased. As an added bonus, the iPod can provide digital equalization, though none is employed in my situation.
Here's a closer look at the set-up:
(http://www.audiocircle.com/image.php?id=74192)
-
Hope the amp driving the headphone socket is good at low frequencies then ! :)
-
Hope the amp driving the headphone socket is good at low frequencies then ! :)
Surprisingly it's quite good. And I'm not just talking about adequate levels to drive the Yung plate amps properly, but sound quality as well. It compares favorably to a variable line out in this set-up. I had reservations as well, but I can assure you it works in this case. The Crown D series amps are considered broadcast quality and have a great rep in the industry. They are also a bit unusual in that the speaker level outputs are not automatically muted when the TRS plug is inserted, and the gain controls from channels 1 and 2 simultaneously drive the gain on headphone L & R respectively. While the impedance may be a bit funky, the Yungs seem to have no problem coping and producing high quality bass.
-
Ed
Found all the drivers and now I'm starting to think about construction details. I am wondering why I couldn't extend the bottom baffle up past the side panels and bolt the top baffle to the front or even back of that, with appropriate anti vibration. That would eliminate the third middle panel. What am I missing? Messing with the time alignment?
Peter
-
Ed
Found all the drivers and now I'm starting to think about construction details. I am wondering why I couldn't extend the bottom baffle up past the side panels and bolt the top baffle to the front or even back of that, with appropriate anti vibration. That would eliminate the third middle panel. What am I missing? Messing with the time alignment?
Peter
Hey Peter,
The lower baffle is offset so the circular side panels have two attachment points, about two inches apart. If the baffle was one piece, all the mechanical points would be inline and the side panels would flex. Splitting the baffle that way makes the entire subwoofer carriage rigid and adds integrity to the upper baffle when they are joined.
-
Hey Ed
Have you kept your sketchup file of the upper baffle? If so would you consider posting it?
I downloaded the basic sketchup. Cool program. Takes some time to figure out, but I found I needed a few more measurements to lay out the baffle. What is the distance from the bottom of the baffle to the bottom of the lower midrange, the ten incher? I think with that measurement I can work my way up. Also, what width is the lower baffle? From the photos I guess you are leaving about a half inch on either side of the Usher to the edges of the baffle. Close?
Are you using the basic sketchup or the pro? Did you design in 3D or use Camera>Standard Views>Top to draw in 2D?
Peter
-
Hey Peter,
I'm excited that you got the SL bug. So far a bunch of people have built the original, but to my knowledge you're the first to try the SL. Please consider starting a page (or use mine) to document your build. I think a lot of people would like that!
I'm using the non-pro Sketchup, latest version. Top view is correct in 2D. If you send me your email, I can send you the .SKP files that you can use. One of the neat things about SketchUp is that you can print a 1:1 ratio template. You do this over several pieces of paper and then cut and tape the template together. This is very helpful in the SL's case since the baffle stock is round. You can overlay the template and trace cut lines on the wood stock, etc.
We're you able to find all of the drivers OK?
-
Ed
Thank you for your help. I very much like the Hestias and find them to be very articulate. I had a great time building them and want to try something more. My curiosity got the better of me and I want to see if the SLs are really better than the originals. And it doesn't cost a fortune to find out.
I was able to find all the drivers, although if took some time. The Celestions from PE have been up and down in price. As low as $5. or $6., I bought them for $12., and they are now at $19. I was lucky enough to find the Vifas and the Usher 8955a pair on the DIYAudio Swap forum. A guy was selling both from an abandoned project. Paid $210. for all four. I don't know what the Ushers retailed for originally, but I was satisfied with the price. I also have seen the Ushers listed on Ebay a couple of times. The last time, a few weeks ago, a new pair was listed for $160. They still seem to be around and available with patience.
As far as posting my build on your page you might have second thoughts when you hear what I am contemplating. I went to Lowe's to buy the round 5/4 tabletops to use for the side panels and top baffle and I was not happy with the pieces available. They were pine with lots of knots and even some split boards and marked stain grade. I don't think so. I wanted to give myself the option of staining the pieces as I did on the Hestias, so I bought the 1" edge glued panels I used before. I don't know the wood, but they are clear and are some type of softwood.
I'd very much appreciate your feedback, but my plan has evolved into cutting a dado in the 1"(finished thickness 3/4") side panels and let the lower baffle into them and two more dados in the feet and let the side panels into them and glue the whole thing together. For the lower baffle I'm thinking stair tread which is 5/4 so I would get a full 1" there. The whole thing would in effect be an I beam with a couple of flanges at one end. I think it would be very stiff, even though I would eliminate the mid baffle, with its offset advantage. I would fasten the top baffle to the bottom with sorbathane spacers and perhaps a stiffener of some sort and use a single sheet of the 1" for the top baffle. Since that baffle is so relatively small and the drivers would act as stiffeners I think the slightly thinner panel would work.
Any thoughts? If it all doesn't work, I could rebuild without a whole lot of additional cost.
Peter
-
Hey Peter,
I sent you the SketchUp file for the top baffle. You can use the measurement tool to get the drivers center point relative to the bottom of the baffle. Note that the drawing shows drivers actual diameter and not the cut-outs, but obviously the center point is the same. You can also use the same tool to show baffle width at the top, bottom and widest point.
You did very well picking up the drivers. I bought several of the Celestion Neos at six bucks a piece. A very articulate and flat mid, provided you use them in their comfort zone, and an absolute steal at that price. The Neo magnet alone would cost more than what I paid for the entire driver.
Your baffle idea should be fine. Try to keep the tweeter around 37.5" from the floor and the others drivers relative to that, or you may have to tweak the crossover values a bit.
Oddly enough my Lowes carries two versions of the same circular stock with the same SKU numbers. One is made by Allwood and the other by a company called Elliotis. I forget which is which, but one is pine and the other is not. Both are relatively soft but the later has fewer or no knots and the board joining is much cleaner. The good news is the last time I was there, they had a new shipment of the superior type, so I'm hoping they were in the process of switching suppliers.
Ed
-
I really dig your final design, thats frickin cool looking. I bet it sounds great! :thumb:
-
I really dig your final design, thats frickin cool looking. I bet it sounds great! :thumb:
Thanks for the comment 6thplanet! There is very little I might do differently, after living with them for about 4 months now.
-
As promised, here's an update to post #19 with final crossover values. It was necessary to wait almost 3 months for the drivers to settle-in.
The value changes are slight and the variable potentiometer has been updated with a fixed resister value for best fidelity.
Low/Mid:
Dayton 10" Pro Sound Driver 8 ohms
L1 = 1.80 mh
C1 = 33 uf
R1 = 7 ohms
Mid Coupler:
Celestion 5" Neo 8 ohms
L2 = .22 mh (18 ga)
C2 = 50 uf
P1 = 8 ohms (or variable 8 ohm potentiometer)
High Frequency:
Vifa XT19TD00-04 4 ohms
C3 = 6.8 uf
R2 = 1.50 ohms
-
Your Shopping Cart
Dayton Audio DMPC-6.8 6.8uF 250V Polypropylene Capacitor
Part Number: 027-424 In Stock$2.93 $5.86
L-Pad 15W Mono 1" Shaft 8 Ohm
Part Number: 260-250 In Stock
$6.75 $13.50
Dayton Audio DNR-1.5 1.5 Ohm 10W Precision Audio Grade Resis
Part Number: 004-1.5 In Stock
$1.25 $2.50
Dayton Audio DNR-7.0 7 Ohm 10W Precision Audio Grade Resisto
Part Number: 004-7 In Stock
$1.25 $2.50
Jantzen 0.33mH 18 AWG Air Core Inductor
Part Number: 255-220 In Stock
$5.26 $10.52
Jantzen 1.8mH 18 AWG Air Core Inductor
Part Number: 255-264 In Stock
$11.79 $23.58
Dayton Audio DMPC-50 50uF 250V Polypropylene Capacitor
Part Number: 027-443 In Stock
$13.80 $27.60
Dayton Audio DMPC-33 33uF 250V Polypropylene Capacitor
Part Number: 027-441 In Stock
$10.14 $20.28
45 Day No Hassle Return Policy Order Subtotal: $106.34
-
Ed
Somehow I managed to post the above list before I was able to edit it. It is a list of what I think I need in crossover parts. Hopefully it is legible. If not I can repost. Am I close?
Thanks
Peter
-
Ed
Somehow I managed to post the above list before I was able to edit it. It is a list of what I think I need in crossover parts. Hopefully it is legible. If not I can repost. Am I close?
Thanks
Peter
Exciting! Someone's got an SL in their future :)
I think I can save you a few bucks. I ended up using the Dayton 100V Non-polarized caps for the 33uf and 50uf applications. In this particular config I could not hear a difference.
027-350 $.98 cents each (33 uf)
027-354 $1.11 each (50 uf)
Also, I used the 8 ohm pot on the Celestion Neo temporally until the speaker was broken-in and then settled on a fixed 8 ohm resistor as the best overall permanent value. You can take advantage of this knowledge and go straight to the 8 ohm resistor in lieu of the potentiometer, while saving yourself a few more dollars and stepping up the SQ slightly. The pot allowed me to dial-in the amount of attenuation while I was tweaking the x/o.
Hope that helps!
Ed
-
Hi Ed
Thanks for the heads up. I just placed an order with the electrolytics. I read a lot of conflicting opinions regarding the them. What sticks in my mind most is that the tolerances can be way off. Do you have any qualms about using them?
Also, is the layout using the 8 ohm resistor (R3?) (+ _ L2 _ C2 _ R3 +)? Are you siliconeing your parts to the board or just using wire ties? I suppose the resistors should stand proud of the board slightly for cooling. I see that some like to eliminate any connection that is not a point to point solder connection. I'm thinking about using some barrier terminals at the inputs and then outputs to the speakers.
I still have quite a way to go, but I thought I would make up the crossover layout before I start gluing the bottom structure together. Hopefully that will lessen the chance of any unwanted surprises.
Thanks,
Peter
-
Hey Peter,
Please see my opinions below, after your questions:
Hi Ed
Thanks for the heads up.
(Q) I just placed an order with the electrolytics. I read a lot of conflicting opinions regarding the them. What sticks in my mind most is that the tolerances can be way off. Do you have any qualms about using them?
(A) Not in this application. I actually bought both and really didn't hear any discernible differences with this crossover, though it can be quite clear in other apps. Regarding their tolerance, perhaps I got lucky in the pairs I was sent, but here too I didn't detect any variances from side to side. Another slight advantage with the electrolytics is their size; they will fit neatly on the crossover board and allow the overall assembly to be smaller. You can always start with the electrolytics and upgrade if you feel improvements can be realized, but I really didn't hear much difference.
(Q) Also, is the layout using the 8 ohm resistor (R3?) (+ _ L2 _ C2 _ R3 +)? Are you siliconeing your parts to the board or just using wire ties? I suppose the resistors should stand proud of the board slightly for cooling. I see that some like to eliminate any connection that is not a point to point solder connection. I'm thinking about using some barrier terminals at the inputs and then outputs to the speakers.
(A) I'm not quite sure what you are asking regarding the layout of the 8 ohm resistor? I used hot glue to secure the components and prevent them from vibrating. Less of a PITA than silicone if you want to reconfigure later. Heat should not be much of a factor, as all three top drivers are very efficient and basically comprise the midrange on up in the SL. They will likely see minimal wattage. You will find that the only driver that gets a bit of a workout will be the LF (Usher). If I touch any of the resistors after hours of play time, they are no warmer than any other component on the board. I used terminals as a matter of convenience but agree that anything you can do to minimize the signal path is a good thing. You may even want to consider three separate boards, which could then be placed in proximity to their drivers, or arranged strategically on the inside rear wings (where a single large board might not fit).
(Q) I still have quite a way to go, but I thought I would make up the crossover layout before I start gluing the bottom structure together. Hopefully that will lessen the chance of any unwanted surprises.
(A) Always a good idea. When you actually wire them up, be sure to listen to each driver individually post crossover, and also be sure to check the phase relationship between drivers. I've made this mistake and find that a test cd, with signals recorded both in and out of phase can be very helpful here. This is especially true in OB, since the rear wave summed with the front wave can sometimes alter the perceived phase relationship at the listening position, even when the drivers are physically wired in phase. If you experience this, sometimes even minute adjustments in distance to any reflective surfaces can correct this.
Thanks,
Peter
-
Thanks Ed
Is this the layout for the midrange crossover? I erased the P1.
(http://www.audiocircle.com/image.php?id=78320)
-
Thanks Ed
Is this the layout for the midrange crossover? I erased the P1.
(http://www.audiocircle.com/image.php?id=78320)
Exactly. The 8 ohm resistor is the last component in series prior to the Celestion mid coupling driver. It attenuates that driver a few dB's and adds some additional resistance to the cap and coil circuit.
-
Oops. I bought the .33mh inductor instead of the .22mh specified in the revised components list. Is there much difference in performance? They are inexpensive, just a little more time.
-
Haha, I have to laugh. I spent more time going back and forth between the .22 and .33 coils than any other component in the x/o design. There is a difference but it may come down to your preference. They actually measure fairly close regarding F/R, but because of the range they affect it seemed to translate into how forward sounding instruments appear within the sound stage; almost like a presence control on a guitar amplifier. I would suggest building it with the ones you have. Since they are fairly cheap just order the others the next time you go to place a parts order. I would love to know your opinion of the two since I agonized over this decision. If you do decide to swap them out later it's a pretty painless procedure.
If it helps in the decision process, the .33's sounded a little less bright in the upper mids by comparison; the center of the sound stage will move back a few feet from the listening position, which was about 8 feet in my case.
-
Ed
I'll take your advice and start with the .33 coils. I am planning to go point to point with all the wiring with no terminals so undoing the soldered bundle of positive leads at the input to replace the .33 with a .22 in the future might be cumbersome but not undo able. I am in no hurry so I could order the .22s and insert them to begin with if you think I'll end up there anyway.
On another note I'd like to pick your brain on stereo imaging. I heard a very expensive system last week and the placement of instruments was very pronounced, almost too much. Solo horns seemed to come from either one side of the stage or the other with no one standing in the middle. On my system with the Hestias and even with previous speakers I don't get much in the way of imaging. The Hestias give a deep soundstage but not much differentiation from side to side. I know everything starts with good source material but where else in the chain can good imaging be lost? I am using a Logitech Squeezebox Touch to bring in internet radio or my music stored on my computer and playing through a DIY Nelson Pass F5 amp. Any thoughts?
Peter
-
Hey Peter,
For starters one of the original Hestia's design goals of low cost dictated a single sub amp which is also crossed fairly high . This design compromise will smear the stereo image a bit, since the left and right channels are summed in frequencies that are still fairly directional. After living with the Hestia's for a bit, I decided to build the Hestia-SL's to improve upon a few things; namely imaging and off axis frequency response. I do like the idea of point to point wiring, and would suggest the .22's if you think substituting them later will be a pain.
Your question about the audio chain is a good one. I have been doing a lot of tinkering these days with audio components and have come to the conclusion that they all play a role in imaging, however the digital to analog conversion stage can be most significant. Whether you use an outboard DAC or rely on the transport's methods of conversion, it is the sound stage qualities that often differentiate between lesser and greater converters. Have you every considered taking the digital feed from your Logitech and passing it through an external DAC? Outboard DAC's run the gamut in price and features, but its very possible to get a decent DAC these days for under $500, and quite a bit lower on the used market. The new crop of asynchronous DAC's such as the Schiit Bifrost, Peachtree Dac-it or Micromega MyDac are all decent. If you have an opportunity to try them out, you may find the contribution they make toward imaging is quite significant. They also handle streaming from a PC or Mac and will usually improve most S/PDIF devices such as CDP's and other players (DVD, BluRay, etc).
I have become enamored with the $99 Pure i-20 digital dock. I use it with my iPhone and iPod. It can extract a pure digital signal from these devices (if you have your own outboard DAC) or it's internal 24bit 192khz DAC is actually quite good as a stand-alone, though you are largely limited to redbook CD quality (16 bit, 44.1) in native mode. I am impressed with its imaging capabilities, given what it costs. While my Hestia SL's are placed about 10 feet apart, I can easily identify instruments that appear dead center, when they are recorded that way. I can also identify a deeper sound stage that I could not so readily do with the original Hestias.
-
Over the past 6 months I've been consulting for a sonar company that makes acoustic transducers. Having access to large scale measurement systems and anechoic chambers, I've been able to apply some newly acquired skills to crossover design.
In doing so I decided to revisit the Hestia-SL crossover. I was fairly confident that the original driver selection would still lend itself well to 1st order electrical (2nd order acoustical) slopes. It's amazing what state-of-the-art measurements can reveal and how much untapped potential there was. Another revelation over the past half year has been that not all passive components are created equal. Far from it in fact! I have really learned to appreciate how components can provide a significant edge in systems that are capable of revealing fine detail. I'm not necessarily referring to boutique priced components; just great sounding caps and coils that wont break the bank.
The specific component combinations listed below provide significant improvement over the initial design.
Low/Mid:
Dayton 10" Pro Sound Driver 8 ohms
L1 = 4.00 mh, Solen 14 AWG Perfect Lay air core inductor
C1 = 31 uf, Bennic non polarized electrolytic, 100V
R1 = 6.8 ohm, Mundorf MOX (metal oxide resistor)
Mid Coupler:
Celestion 5" Neo 8 ohms
L2 = .22 mh, Solen Perfect Lay 14 AWG
C2 = 5.6 uf, Clarity Cap ESA, 630V
R2 = 5.6 ohm resistor, Mundorf MOX
High Frequency:
Vifa XT19TD00-04 4 ohms
C3 = 5.6 uf Mundorf EVO aluminum oil capacitor, 450V
(No further attenuation required in new crossover design)
-
Hi Matevana,
a multiway speaker's xo slopes /nad thus off-axis performance) will get a major bnefit from Duelund approach. It is kind of twin xo to make acoustic responses to maintain coherent phase shift even past xo point. Then of-axis measurements were greatly improved, with added clarity when listening to music. A dipole's low end naturally makes that but low-pass needs more shaping.
http://www.musicanddesign.com/Duelund_and_Beyond.html
I found moving from LR2 to LR4 acoustic (with duelund approach) very beneficial with my AINOgradient project. I use minidsp for xo and eq - much easier than passive, but I need 8 amplifier channels to drive them! http://www.diyaudio.com/forums/multi-way/231353-aino-gradient-collaborative-speaker-project-37.html#post3695824
-
..and just one more thing!
After going ot "Duelundish" xo my dipoles stopped sounding "OB" Kind of sad :roll:
-
Yes, I read about the concept when John K put it on his site. Interesting stuff and nice set-up by the way! My experience with MiniDSP wasn't all that positive, but it was a first generation model. Since that time a lot of folks have done some impressive things with bi-quad programming.
Can you elaborate about your speakers sounding less like OB with the different slope?
-
OB-sound is kind of joke... I don't have any other dipoles at home but I have listened to some others.
When I started my project I thought that acoustic LR2 would be best. Then I went outdoors and made measurements with higher level (distortion check) and off-axis up to 180¤ Distortion results made me to try LR4 and response shaping beyond xo. To my surprise off-axis response was much more even (better phase match) and also distortion was lower (easier job in low end) This with same on-axis response!.
When I carried the speakers back in, they sounded really different. Airyness was nearly gone but sound was clarified and bass-mid sounds were much better controlled. Kind of like less reverbs in the room. They sounded almost like my 2-way monitors, still better though!
-
OB-sound is kind of joke
You lost me, can you explain?
I ran OB mains for over 7 years, and while no speaker I have owned was perfect, boy were they entrancing with certain music.
For the record I am currently using 2 way monitors and sub, my circumstances no longer allow for 36 inch baffles and the nest of wiring my speakers used to be!
That said, I am not done with this approach, once the kids leave and the basement is mine again (finished it over the winter, and suddenly more users are appearing, and sharing their opinion!) I will be back.
-
(http://www.audiocircle.com/image.php?id=90238)
(http://www.audiocircle.com/image.php?id=90239)
This how my "Duelundish" slopes look like. There is also "inverted" curve to show summing of each drivers and non-inverted overlap of W to HM and LM to T. Step response too.
"OB-sound" was a joke in my message! The sound itself is not a joke. At least I like them.
See my previous post for explanation
-
I disagree with the premise that the low pass filter always benefits by having more shaping. One of the goals of the Hestia project was the use of low slope first order electrical crossovers. Granted these can't often be used. But with the use of highly compatible drivers and proper crossover points they can sound better than anything else. Linkwitz was criticized for using first order electrical between the two mid bass drivers, but for those who have listened to the LX-521, they report that the driver coupling is flawless. A drivers dynamics are often times less at risk of compromise with a single component crossover then with a more sophisticated approach.
-
I am glad that you are happy with your project!
It has been a long road and learning process for me to measure and develop AINOgradient. Here I show two directivity graphics - before and after I gradually went to LR4/Kreskowsy filters. I have saved most of my measurements and minidsp configurations.
Original Duelund xo is practically like acoustical LR2 up to xo-point, then shifts to LR4.
My implementation tries to follow Kreskowskys n=4 principle, starts as LR4 and then deepens even more.
Both are measured same way in the middle of my living room, here I show 12ms gated measurements at angles 0¤, 30¤ 60¤ and 90¤ Motice the great difference at 60 and 90¤. Direct sound is similar but reflected sound is also phase-coherent now -anyone will hear the difference. I have my speakers on the long wall of the room 2,5m apart, listening distance 2,5m, speakers toed-in 45¤.
v62 has LR2 for W/LM/HM and LR4 for HM/T
vXX4 has LR4 for every xo
(http://www.audiocircle.com/image.php?id=90276)
(http://www.audiocircle.com/image.php?id=90277)
-
Looks good Juhazi. Perhaps you could start a separate thread about your AINO speakers as not to thread-jack Matevana. Make sure to include pics of the speakers :wink:
cheers,
AJ
-
Looks good Juhazi. Perhaps you could start a separate thread about your AINO speakers as not to thread-jack Matevana. Make sure to include pics of the speakers :wink:
cheers,
AJ
Thanks AJ! I see that you attend performances at USF a lot. I work for the state university system in FL and visit there often.
-
Sorry about hijack-attempt!
I have linked my own thread with loads of pictures and measurements earlier, here again. You have to register to see attachments. My avatar speaker is AINOgradient.
http://www.diyaudio.com/forums/multi-way/231353-aino-gradient-collaborative-speaker-project.html
Occasionally I jump over this forum too and I have followed matevana's Hestias from the beginning. The general concept is very nice and "pure"! The problem for me is lack of measurements shown, it has been very difficult to evaluate and comment it. My problem.
Greetings,
Juha
-
I see that you attend performances at USF a lot. I work for the state university system in FL and visit there often.
Unfortunately don't attend near as much as I use to, now that I am a "business" :(
Shoot me an email to soundfield next time you're in town. Actually doing a demo for the local audiophile club http://www.meetup.com/Suncoast-Audiophile-Society/events/past/?scroll=true#past (http://www.meetup.com/Suncoast-Audiophile-Society/events/past/?scroll=true#past) this weekend. Not dipoles :wink:
Juha, is that your speaker in your avatar?
cheers
-
Winter must be coming. The threads are starting to get active. I finished a pair of SLs early in the summer, but because of some other equipment issues am only now getting around to posting. That is I thought I had finished until I saw Matevana's posting of upgraded crossover components. Ed, how much difference do the new components make?
Compared to the original Hestias I find these to be more detailed and to have a more fuller sound. I like them and my audio buddies do also. There is also plenty of bass. At this point I am using the Yung 300 watt plate amp with boost in a mono hookup as in the original Hestias. Although I know the boost has something to do with the full bass I think the Ushers and the H frame are a very good combination. I have to be careful not to give the Ushers too much gain and perhaps will add the FMODs Matevana has mentioned elsewhere. Parts Express has just put all the Yung plates on sale and so I will be buying and upgrading to stereo. I will certainly be going with a non boost amp, but I wonder at what wattage. I am driving the top end with a 25 watt Nelson Pass F5 so the 300 watt seems a bit of overkill. I think I will at least move down to the 200 watt model and wonder if even the 100 watt version would be appropriate? On sale there isn't all that much difference in price on all three models.
As can be seen in the photos I tried to isolate the top baffle from the H frame in this case with Sorbathane between the two and rubber washers under the bolt heads. There is still a fair amount of vibration on the top baffle, although quite a bit of it might be coming from the low mid Dayton. I don't know if it affects the sound much but perhaps separating the baffle from the H frame and giving the baffle its own stand might reduce vibration.
These speakers are very good. They are not that much more complicated than the Hestias and the sound is amazing.
Peter
(http://www.audiocircle.com/image.php?id=90373)
(http://www.audiocircle.com/image.php?id=90374)
(http://www.audiocircle.com/image.php?id=90376)
(http://www.audiocircle.com/image.php?id=90378)
-
Hello sjhomey and Ed,
Really enjoyed this and the original Hestia. Awesome build threads and kudos to Ed on these AMAZING designs... THANK YOU ED!! I also totally appreciate the design approach as well using the Ashely crossover and tweaking by
ear. Focused on the sound of music (not a software exercise, quick to progress the Xover design and above all... practical.
I'm new to OB and very interested in both of these designs. I'm inclined to try the original just to learn but really do like the more detailed/resolution promised by the Dayton 10 over the MCM used as the mid in the SL (and the
general advantage of using a larger driver as the mid, I've heard that 8-10 inch mids seem to the preferred for vocals, horns, piano, etc). If I do go with the more simple design of the original I wonder what work it would take to
replace the MCM with the Dayton?) Of course sticking with the original design is always the best, most conservative approach and will yield excellent results but with you working the Dayton as a mid in the SL I thought I would simply ask the question. What are your thoughts Ed? Can it be done with minor tweaking/should I even consider? Is there a gain to be had (Hestia v2?)? I have used Jeff Bagby's PCD/design tools and can probably model both designs in regards to the XOvers to see the impact on the 2 designed if you feel it is a reasonable modification. Sorry for the questions... just pumped... was up to 4:30 last night reading the threads and looking at OB design. ;-)
I am REALLY excited to begin my first OB build. Your designs struck a chord with me as I was eyeing up the Yung plate amps (can't pass up a quality amps for $89/$99) and had the MCM woofers on the short list... destiny? has
sjhomey, if it not too much to ask, can you weigh in on the original and SL? I'm curious what you think of the 2 designs independently and comparatively?
-
Hey Peter,
Nice job! The recent crossover change is one of refinement and coherence. I listen to a lot of acoustic music and jazz instrumentals and the improvement is significant. However with music that uses a lot of compression the differences are not as significant. It mostly affects the handshaking between the Dayton woofer and the Celestion mid driver. There is a lot less overlap in the current design and that translates to a more coherent (but slightly less full) upper bass section.
The ushers are amazing drivers and can handle a fair amount of abuse without complaining. If you are making the transition to stereo bass, I would recommend the 200 watt Yung units w/o boost. Remember they will now be running at 8 ohms per side, so the amps output will be halved (approximately). Don't worry though. The 200 watt amps will provide plenty of headroom.
-
Sorry Ed, I saw the post about the original Hestia where you switched the Dayton and MCM and adjusted the crossover to adjust for the Dayton as a mid. BINGO... Thanks! So thats a finished design as I'm sure I can go with the Dayton both on the bottom and mid. So long as i go with the Yung amps I assume.
Do you think Dayton is an upgrade (man, the price of the MCM is attractive... but if I'm going to take the time to build the baffle, I might as well go for the more detailed option. Imagining the more deailed Daytons might sound better with my warmer sounding Fountek tube amp)?
Any subjective insight would be much appreciated. I'm sure i can't go wrong with either!!!
Thanks again!
Rich
-
Sorry Ed, I saw the post about the original Hestia where you switched the Dayton and MCM and adjusted the crossover to adjust for the Dayton as a mid. BINGO... Thanks! So thats a finished design as I'm sure I can go with the Dayton both on the bottom and mid. So long as i go with the Yung amps I assume.
Do you think Dayton is an upgrade (man, the price of the MCM is attractive... but if I'm going to take the time to build the baffle, I might as well go for the more detailed option. Imagining the more deailed Daytons might sound better with my warmer sounding Fountek tube amp)?
Any subjective insight would be much appreciated. I'm sure i can't go wrong with either!!!
Thanks again!
Rich
Hey Rich,
Glad you are considering the design. Due to space limitations I no longer have my original Hestia's, but if memory serves I actually preferred the MCM driver in that configuration over the Daytons. It's a bit of a balancing act but sometimes a slightly more revealing driver isn't always a good thing. For example, I mostly prefer the smooth sound of a paper midrange over a more revealing aluminum cone. If you are going to use the Dayton in the original Hestia, I would recommend using the zobel network added to the SL's crossover, so the driver presents a more friendly load to the amp and the crossover tracks better. This is not necessary with the MCM. I also liked the combination of the original MCM with the Vifa D19, more so than I did with the Dayton. It would be good to hear what others think as well. I hope this helps.
Ed
-
I am considering building a pair of these. They look really nice. I like the idea of a Active/Passive hybrid system that would only need bi-amping. I was wondering if you think that the top half of these would work with standard MJK h-frame alphas? I have a pair that are already made, I am considering a design that would take the top of your design and place it on the current h-frames.
Currently have a mini-DSP and rotel rb-1050 that is running the h-frames from the mono output of my Decware preamp. I'd be powering the Hestia-SL tops with a set of 9-watt 300b monoblocks.
you are using the lower h-frames from 25 Hz - 100 Hz, correct? Do the tops run with a full-range signal, or are you using fMods to LP them?
Thanks for the great design!
-
Hi Danvprod,
That is almost exactly the design concept I am working on right now. The top end will consist of the current Hestia-SL using the new crossover. There is no high pass f-mod so the 10" Dayton rolls off naturally. The bottom end will be a tandem H-Bomb enclosure with two 10" drivers per side. The woofer alignment will be side by side to allow maximum benefit from floor bounce. The drivers will likely be Peerless SLS's based on a nice blend of performance and price. I happen to be sitting with a quad right now. The compressed fiber H-bomb design has proven to be very effective in damping cabinet resonance. They are also very light and easily slid away from the front wall in operation.
The top half of the Hestia-SL will remain in tact, with a new base that goes down to the floor and sits behind the dual H-frames. This will serve to decouple the Hestia from the bass section and provide the necessary offset to address time alignment. The dual woofers should add an additional 9-12 dB of headroom, which should significantly improve the current SPL capabilities.
I'm guessing you could power the tops adequately as you describe. I tested the top sections with a small tripath chip amp outputting 10 watts per channel into 8 ohms. They sounded amazing with the new crossovers and played loud and clean.
-
Hi Matevana --
Thank you very much for the answer, and the insight. Those H-Bomb enclosures look pretty cool. Neat idea on using the pre-fab storage cubes.
Would you be willing to send me the sketch up file of the final baffle, so that I can print it out full-size as a template?
-
Hi Matevana --
Thank you very much for the answer, and the insight. Those H-Bomb enclosures look pretty cool. Neat idea on using the pre-fab storage cubes.
Would you be willing to send me the sketch up file of the final baffle, so that I can print it out full-size as a template?
Sure thing. If you PM me on here with an email address, I will send the .SKP file.
-
Sure thing. If you PM me on here with an email address, I will send the .SKP file.
Dan,
I sent the Sketch-up file to your Google mail.
Ed
-
sjhomey, if it not too much to ask, can you weigh in on the original and SL? I'm curious what you think of the 2 designs independently and comparatively?
I had a chance this weekend to put my Hestias back into my system. I still feel the same as mentioned in my post above. The Hestias sound better than I thought they would after listening to the SLs for awhile, but the SLs are tighter and more articulate. They are more time and money but well worth the effort. On the other hand the Hestias are no slouch. They have a big open sound to my ear that is quite pleasing.
-
Since a few people have asked, the latest iteration will make use of double H-bombs in a completely separate alignment, similar to what Martin King has done with his Lowther/Acoustic Elegance combo. I think it's really smart to keep the bass drivers as close to the floor as possible (side-by-side). The H-bombs have proven themselves as viable structures over the past few months.
I plan to keep the Hestia-SL top section as-is. I am very happy with the design. The only problem is the new crossover allows for higher SPL's and the single 8" Usher may not be able to keep up with the demand... thus the need for a beefier bottom end. The top section will be stand mounted and sit behind the H-frames, isolating the baffle from additional vibration. The foot of additional floor space should be close to ideal in time alignment when I factor in the distance to my listening position.
Here's what I have so far. Gotta love the the ease of the cube's assembly, along with cleats and mechanical fasteners.
(http://www.audiocircle.com/image.php?id=90776)
(http://www.audiocircle.com/image.php?id=90777)
(http://www.audiocircle.com/image.php?id=90778)
-
Nice! Love the double h-frames. Very good idea to run these like MJK does with his setup. Fit and finish on these look great, too. As a slight aside, I just love the flexibility of the h-frames.
Looking forward to how these shape up with the Hestia-SLs. Did you decide on a woofer to use in your h-frames?
-
Nice! Love the double h-frames. Very good idea to run these like MJK does with his setup. Fit and finish on these look great, too. As a slight aside, I just love the flexibility of the h-frames.
Looking forward to how these shape up with the Hestia-SLs. Did you decide on a woofer to use in your h-frames?
I will probably go with a quad of Peerless 10" SLS for the main reasons that I have them available and John K seems to like them for his new Nao Note II RS. They are also relatively inexpensive. I really like the Ushers but it would be hard to justify the cost of four. One of my biggest peeves about woofers used in open back is their motor noise; I'm sure John K has vetted this out in his woofer selection even though I have yet to hear them for myself.
-
Do you have the 10" Peerless SLS Subwoofers or regular woofers? The subwoofers: http://www.parts-express.com/peerless-830668-10-paper-cone-sls-subwoofer--264-1110 have a Q of 0.55 and Fs of 32 Hz. Or the woofers: http://www.madisoundspeakerstore.com/approx-10-woofers/peerless-sls-830668-10-woofer-coated-paper-cone/
Looks like the woofers are not sold by PE anymore, but the subwoofers are. Maybe the subwoofers are just a new version of the woofers?
Are you still planning on powering your quad subwoofers with a Yung plate amp? Do you envision needing any additional frequency shaping or active components in the H-frames to work with the Hestia-SL tops?
-
Do you have the 10" Peerless SLS Subwoofers or regular woofers? The subwoofers: http://www.parts-express.com/peerless-830668-10-paper-cone-sls-subwoofer--264-1110 have a Q of 0.55 and Fs of 32 Hz. Or the woofers: http://www.madisoundspeakerstore.com/approx-10-woofers/peerless-sls-830668-10-woofer-coated-paper-cone/
Looks like the woofers are not sold by PE anymore, but the subwoofers are. Maybe the subwoofers are just a new version of the woofers?
Are you still planning on powering your quad subwoofers with a Yung plate amp? Do you envision needing any additional frequency shaping or active components in the H-frames to work with the Hestia-SL tops?
I believe both drivers are the same. If you notice they both reference the same Peerless manufacturer #830668. It's possible that the TS specs have changed slightly over the years. The same specs are shown on the Tymphany website so I believe they are accurate.
I currently use a B&K power amp to drive the woofers, along with an F-mod passive inline filter. The Yung amps sounded fine; but I did experience a few failures while they were under warranty. I decided to go the route of (used) vintage amps instead, for about the same coin. I really like B&K stuff.
-
Thanks, I missed the same PN in the spec sheet on PE. Should be a nice setup. Good info on the B&K amps. I have been driving my h-frames with a Rotel RB-1050 that I scored on criagslist. It's a nice high-quality amp and I haven't felt the need to upgrade. Using it currently with the Mini-DSP to cross over the h-frames.
-
(http://www.audiocircle.com/image.php?id=91348)
Testing the SL tops with the new double h-bomb frames. As expected the crossover will have to be re-voiced slightly. I am working on that now. Sounded good off the line but the four SLS woofers will improve over time. The surrounds are very stiff and will benefit from some play time.
-
If you like it. Are you going to attach the h-bombs to the SL tops ?
Or keep them separate ?
-
Yes, exactly. I'm working on separate bases for the Hestia SL tops that will allow table-top mounting (or bridge mounting) on the double bass bins. In Sketch-up it looks pretty cool.
-
Hi Matevana
I see the crossover components you spec for the Hestia-fortes are somewhat different than the revised component list you posted here in November. Have you settled on the Hestia-forte list as the final design or do you still like the components listed here? I think the Hestia-forte's are a little cheaper and simpler.
Peter
-
Hey Peter,
The SL requires a different crossover due to the way the Usher 8955 interacts with the design vs. the twin Peerless on the Forte. The LF slope on the Forte is steeper in effort to keep the Peerless from playing too high; this design also sheds the zobel-like circuit for similar reasons and therefore reduces the component count. Conversely the 8955 sounds better crossed higher and is instrumental in the SL design. The zobel circuit in the SL is needed to help the crossover track better, due to its more shallow slope. Finally the Neo's inductor value is slightly different on the Forte, again to conform to the desired voicing of this design.
Ed
-
If anyone is interested in building these, I have about 10 of the Dayton 10" pro sound drivers in a bulk pack. I will let them go in pairs only. Just make a reasonable offer.
-
Hey Ed,
Really impressed with your Hestia-SL design. I've been 4+ years evolving my open baffle until I present, which now is the Alpha 15, Tang Band 1808 and a tweeter. I almost pulled the trigger by ordering the drivers for your Hestia design until I read about the Hestia-SL. Now I may have to build both!
I heard the Linkwitz 521 at the Rocky Mountain Audio Fest and was convinced to build it. The main drawback for my was powering it with a 70lb. 8 channel amp. (plus all of the other assorted electronics). I prefer simple designs and tubes or good lower powered solid state.
I am at the point where I would like to move on from my current open baffle to something with a slightly less footprint and the SL is perfect in that respect. A couple questions regarding the SL design.
I see that you have upgraded the low end with the H-Frame design. In keeping with the small footprint, could the 8" Usher be upgraded to a 10" driver? Or possibly the Peerless SLS 830452 used by John K in the Neo II? (I thought of converting my Alpha 15 to two 10s just to narrow the baffle a bit. )
You stated that the primary difference between the Hestia and the SL as 'resolution and detail'. As I progress with my open baffle design, early on with average drivers both tubes and solid state sounded about the same. As I tweeked the components and drivers, the tubes sounded better. Do you think one of the First Watt amps, ie. J2, F3, etc. would be a good match with the SL and not be too analytically sounding?
Again, great work and thanks for sharing.
John
pm you regarding the drivers.
-
Hey John,
Thanks for the kind words. Let me try to answer your questions. First off, you could absolutely replace the Usher 8955 with a variety of decent 10" drivers with almost no consequence to the design. I would try to keep the baffle width as close to the original design as possible and the driver height at the same relative proximity to the floor.
The SL takes full advantage of all drivers operating within their comfort zone. The selections are also fairly flat within their pass band which helps minimize the component count. The atypical crossover points (overlap/underlap) coupled with a varying degree of driver efficiency help compensate for dipole roll-off and eq. irregularities, again minimizing the need for active compensation. These ideas combined result in greater resolution and detail compared to the original Hestia design. The top 3 drivers have a combined system efficiency of 92 dB and will perform well with a variety of amps including most SET's. They also have a fairly innocuous impedance curve. I have not heard the system with a First Watt but I would bet the combination sounds fine.
The latest iteration replaces the Dayton Pro Sound driver with a 10" hemp cone driver for even less cone breakup and a smoother transition between the lower and upper midrange. I am very pleased with this upgrade.
Unfortunately all of the 10" drivers I had left over from my bulk order with PE are now committed.
Ed
-
I've been listening to my SLs with the updated crossovers for close to 200 hours now. They sound very good. Well worth the extra cost, although I did scimp on the inductors. That cut down on the cost. I am using a home built Nelson Pass F5 amp. It plays the SLs very well.
Although I keep saying I'm finished, the hemp mid sounds intriguing. Currently I'm digitizing some of my older vinyl, an interesting nostalgic project.
Thank you Matevana.
-
Hey Peter,
Glad to hear you like the new crossover design. I've always felt that inductors are less intrusive than capacitors so I too would have skimped in that area given the choice.
The Eminence Lil Buddy hemp cone is a direct drop-in for the Dayton PA-255, at least as far as the cut-out diameter and mounting holes are concerned. The driver is actually more efficient than the stated 4 dB difference between the two, so you will need to use an L-Pad (two resistors) to reduce the output a bit. You can do this at the drivers terminals if you are worried about messing up the aesthetics of your already completed crossovers. They are very smooth. They also have a higher Qts and FS than the Daytons, which lends itself well in this design. Linn Olsen reviewed a 12" hemp cone guitar speaker as a hi-fi driver and really liked it. You can read about it on his nutshell high fidelity website.
Lastly, if there is one more tweak you may be interested in trying, take a look at the woofer crossover topology in the Hestia Forte project. It provides two different slopes at the same time in a passive set-up. The 12db/oct line-level crossover addresses the overall low pass function while the 6dB/oct speaker level inductor specifically addresses dipole roll-off. I have not seen this done before passively but it works very well if you're looking to avoid a more complex crossover. Mine is implemented monaurally in the Forte design, but it is easy to modify for stereo subs. Due to a minimal component count it is very transparent.
Ed
-
Hi Ed,
Glad I waited to buy my drivers - the Lil Buddy sounds like a great upgrade. You mentioned that the crossover basically stays the same except for a couple of resistors to balance the sensitivity in the system. What value resistors do you suggest?
At least for now I'm stuck with an amp without pre outs so I will try to build a different low end. Do you think a single Alpha 15 (passive) in a H-frame configuration would work? Later when I find an appropriate amp/pre I will upgrade to the SLS with a plate amp.
John
-
Hi Ed,
Glad I waited to buy my drivers - the Lil Buddy sounds like a great upgrade. You mentioned that the crossover basically stays the same except for a couple of resistors to balance the sensitivity in the system. What value resistors do you suggest?
At least for now I'm stuck with an amp without pre outs so I will try to build a different low end. Do you think a single Alpha 15 (passive) in a H-frame configuration would work? Later when I find an appropriate amp/pre I will upgrade to the SLS with a plate amp.
John
Hey John,
The Lil Buddy is more efficient (and detailed) than the Dayton PA255 in its midrange and can be attenuated with 2 resistors in a conventional L-Pad. I used the Mundorf MOX 10 watt resistors as follows:
R1 = 6.8 Ohms
R2 = 2.7 Ohms
(http://www.audiocircle.com/image.php?id=96355)
Note that the parallel resistor (R2) in this design should be the smaller of the two values (2.7 ohms). This is intentional. The Mundorf MOX are the best sounding resistors for the money that I have found. At $2.50 a pop they represent cheap insurance in any design and are well worth the cost. Their metal oxide blend is far superior to the ceramic core resistors IMO.
If you chose the Lil Buddy upgrade, I also recommend changing the value of the single resistor used in the upper mid Celestion Neo driver to 27 ohms. This will yield a proper level balance between all three drivers and measure more favorably.
I see no reason why you cant use a single Alphas for the low end in the interim. Ultimately the Usher or Peerless drivers will provide even better results, but you can easily cross that bridge at a later time.
Let us know what you decide to do!
Ed
-
Hi Ed,
Having been on a speaker building sabatical for a couple of months now, I've started assembling drivers and parts for the Hestia-SL only to find a couple of new impressive design builds with the Hestia V Dome!
I had planned to use the Lil Buddy as you suggested, but I see two new different drivers in the V. I've heard the Seas before and really like it. I also see the Eminence Legend as a replacement for the Lil Buddy.
Wondering if I should continue on the SL and move up to the Hestia V. What are the sonic advantages?
After a conversation with a friend about a low end driver, and in an effort to keep the overall profile on the slim side, he suggested as an upgrade to my Alpha 15, the Eminence Definimax 4015lf.
John
-
Hi Ed,
Having been on a speaker building sabatical for a couple of months now, I've started assembling drivers and parts for the Hestia-SL only to find a couple of new impressive design builds with the Hestia V Dome!
I had planned to use the Lil Buddy as you suggested, but I see two new different drivers in the V. I've heard the Seas before and really like it. I also see the Eminence Legend as a replacement for the Lil Buddy.
Wondering if I should continue on the SL and move up to the Hestia V. What are the sonic advantages?
After a conversation with a friend about a low end driver, and in an effort to keep the overall profile on the slim side, he suggested as an upgrade to my Alpha 15, the Eminence Definimax 4015lf.
John
Hey John,
Great question. The Lil Buddy has a unique voicing that is very pleasing, and works well within the context of the SL. It is somewhat dark sounding, with little or no breakup and very smoooooooth! This is especially appreciated if you listen to lower rez music that is compressed. Not as harsh on the ears. The maximum volume is limited to the physical excursion of the Lil Buddy, which is a bit less than other drivers with more xmax. Note that the Lil Buddy is first and foremost a guitar speaker, very seldom generating tones below 100 Hz.
The Hestia V and Hestia V Dome are similar designs, but employ an Eminence Bass Guitar driver which is very efficient, uses a whizzer cone for extended mids, and has 4-5x the maximum excursion. I randomly came across this driver while doing a repair, and I really liked it. In fact, it is now my favorite low mid driver for OB. It just seems to have the right combination of characteristics. It also seems to be very accepting of a variety of mids and high frequency driver combinations.
I also REALLY like the Seas Curv cone series of mid couplers. Both the FU10 and MU10 are great sounding drivers. Whatever the cone technology (combination of materials and weave) is, Seas has produced a really exceptional mid at a reasonable cost. I don't have enough play time with the MU10 to recommend one over the other... but nothing bad to say about either.
If you haven't collected all the drivers yet and there is still time, I would suggest building either the Hestia V or Hesta V Dome. The end product is a notch above the SL.
Ed