[Squidspeak]

How true, probably half my friends from my youth now reside in the Sunshine State

[matevana]

How true, probably half my friends from my youth now reside in the Sunshine State

Yeah, but you can probably chalk that up to Snooki and Jay-Wow

[sjhomey]

I've spent the last week listening to a pair of Hestias on test baffles. Its all plywood and alligator clips. I am most impressed. My first exposure to OB and its all true. Big soundstage, depth, and detail. Thank you Matevana. I am using two sets of MCMs instead of a second pair of Daytons. Lots of bass response. Even with the Yung amp turned down my old wooden floors are jumping around. I've been trying different amps and moving the speakers around and like the openness and fullness of this design. I thought the top end was somewhat harsh at first, but that is disappearing. Could the top end drivers be breaking in after only 10 or 12 hours?

The only complaint I have is that even though the sound is very full I still can tell that it is coming from a point lower than my listening level, even with the baffles angled up. I would like to move the tweeter up to ear level somewhere around 33/36". As I see it I can add 10 or 12 inches to the bottom of the baffle and move the whole configuration up, which along with any other effects would decouple the bass from the floor. Or I could add more baffle and move the tweeter/mid up and leave the bass down leaving a gap in the middle of the baffle. Thirdly, I could add a second mid, wire the two in series and thus keep the same SPL as just one . I wonder if doing that would give more continuity from the tweeter down to the floor. I sort of like that third idea. Would these changes, which at the very least would add to the size of the baffle, compromise the design in other ways?

On a side note Matevanna I've been reading about the 2x rule of thumb, making the baffle at least two times as wide as any adjacent driver. What are your thoughts on that? You obviously didn't feel constrained by that rule on the Hestia.

The music is great. Thanks for making it easy and affordable for at least one rookie to enjoy the sound of OB.
 

[matevana]

I've spent the last week listening to a pair of Hestias on test baffles. Its all plywood and alligator clips. I am most impressed. My first exposure to OB and its all true. Big soundstage, depth, and detail. Thank you Matevana. I am using two sets of MCMs instead of a second pair of Daytons. Lots of bass response. Even with the Yung amp turned down my old wooden floors are jumping around. I've been trying different amps and moving the speakers around and like the openness and fullness of this design. I thought the top end was somewhat harsh at first, but that is disappearing. Could the top end drivers be breaking in after only 10 or 12 hours?

The only complaint I have is that even though the sound is very full I still can tell that it is coming from a point lower than my listening level, even with the baffles angled up. I would like to move the tweeter up to ear level somewhere around 33/36". As I see it I can add 10 or 12 inches to the bottom of the baffle and move the whole configuration up, which along with any other effects would decouple the bass from the floor. Or I could add more baffle and move the tweeter/mid up and leave the bass down leaving a gap in the middle of the baffle. Thirdly, I could add a second mid, wire the two in series and thus keep the same SPL as just one . I wonder if doing that would give more continuity from the tweeter down to the floor. I sort of like that third idea. Would these changes, which at the very least would add to the size of the baffle, compromise the design in other ways?

On a side note Matevanna I've been reading about the 2x rule of thumb, making the baffle at least two times as wide as any adjacent driver. What are your thoughts on that? You obviously didn't feel constrained by that rule on the Hestia.

The music is great. Thanks for making it easy and affordable for at least one rookie to enjoy the sound of OB.

Hey SJ.

Thanks for the feedback. I can tell you from experience that they will only get better after another 75 - 100 hours of break-in, perhaps even twice as good as what you are now hearing. The D-19 tweets will mellow and the stiff accordions on the MCM's will loosen up; more importantly the Thiele-Small parameters will settle into alignment with the crossover design. For this reason you should continue to listen on the test baffle for a little longer, before coming to any design change decisions.

If you do decide to experiment with baffle height, I would strongly suggest keeping the upper MCM and Vifa D19 as a system, in the same relative distance to one another and with regard to the top of the baffle. I strongly recommend leaving the LF driver (in your case the 2nd MCM) in the same position as the original design. This is critical in dealing with floor bounce and not experiencing any 100-300 Hz suck-out as a result of cancellations. Moving the driver up will not decouple it from the floor, but rather change the critical integration with the mid/tweeter pair. You will likely experience a hole in the critical vocal region as a result.   

If you decide to try adding a 2nd MCM driver in series, two things will likely happen. The crossover component values will need to be  reworked as you will be changing the effective system impedance (16 ohms in series).  You may also change the voicing of the Hestia design as a MMT, particularly off-axis. 

From my tinkering, I found that a 13" baffle width for the mid/HF pair was the best overall compromise. Regarding the LF driver, you could certainly benefit from additional baffle width, perhaps as much as 20". In coming up with a design that might be easy for others to replicate, I chose a 15" overall baffle width and fine tuned the component values and driver spacing accordingly. I believe that Squidspeak has the right idea in considering a baffle that widens to accommodate the LF driver, similar to what John K did with his Nao Note design. This would minimize LF cancellation while preserving positive imaging characteristics up top.

I do not want to discourage you from trying what you propose, especially since you already have the 2nd MCM driver on hand for the other speaker. Just wanted you to consider some of the points above, so you may better anticipate the cause/effect relationship of the suggestions.

Ed       

 

[sjhomey]

Ed
Thanks for setting me straight. I will continue to listen for a while before I make any final changes on a permanent baffle. I did however make a few reversible changes. I lifted the baffles, first 6 inches and then 12, roughly, to see how tweeters at ear level would sound. Surprisingly to me it didn't change that much, although a little bit. Even on the floor the soundstage seems to be slightly above the baffles.

However, I think I did hear the floor bounce effect, you mentioned, when the baffles were elevated to 12 inches. Big time. I am listening about 8-10 feet away and when I sat forward the full sound was there. Sitting back about 18" or so and the vocals just went into a box. Nothing subtle at all. They attenuated dramatically. I assume it was a result of the floor bounce, especially on the lower midrange. I read some consider that floor bounce effects are minimal but what I heard was significant. At 6 inches high, I heard no negative effect at all.

I will listen quite a bit more, but I think I liked the sound a little better with the baffles a little higher. Definitely not 12 inches higher, in this room. What effect would splitting the bass and midrange drivers about 6 inches have? That is keeping the bass driver down where it is and lifting the mid/tweeter combo? Hopefully, I am not being too much of a pain with all these questions, I'm just interested in what different tweaks would do. I'll be following Squidspeak's progress on a wider baffle bottom.

Peter

[matevana]

Hey Peter,

Not a pain at all     You should be fine leaving the LF driver where it is on the baffle, and raising the Mid/tweeter to a more suitable height. Another thing you may wish to try, is to have the drivers cross a little bit forward of the listening position. If you think of your seated position, the left speaker and the right speaker, each as a point on a triangle, angle the speakers so their line-of-sight intersects about a foot or two in front of your position. Many people find this to have a positive effect in OB.  It will also increase slightly the distance of the wall behind the speakers, w/o changing the relative position.

I may be partial to floor standing designs, so the fact that the tweeter level is lower than the seated ear level doesn't bother me. I find that angling the panels back slightly helps compensate for this, but others may prefer the height you suggest.  I like to look at SL's Orion as one of the pinnacles in OB design; if I remember correctly he has the mid woofer around 34" off the ground, and the tweeter around 42".

[Squidspeak]

Ed
Thanks for setting me straight. I will continue to listen for a while before I make any final changes on a permanent baffle. I did however make a few reversible changes. I lifted the baffles, first 6 inches and then 12, roughly, to see how tweeters at ear level would sound. Surprisingly to me it didn't change that much, although a little bit. Even on the floor the soundstage seems to be slightly above the baffles.

However, I think I did hear the floor bounce effect, you mentioned, when the baffles were elevated to 12 inches. Big time. I am listening about 8-10 feet away and when I sat forward the full sound was there. Sitting back about 18" or so and the vocals just went into a box. Nothing subtle at all. They attenuated dramatically. I assume it was a result of the floor bounce, especially on the lower midrange. I read some consider that floor bounce effects are minimal but what I heard was significant. At 6 inches high, I heard no negative effect at all.

I will listen quite a bit more, but I think I liked the sound a little better with the baffles a little higher. Definitely not 12 inches higher, in this room. What effect would splitting the bass and midrange drivers about 6 inches have? That is keeping the bass driver down where it is and lifting the mid/tweeter combo? Hopefully, I am not being too much of a pain with all these questions, I'm just interested in what different tweaks would do. I'll be following Squidspeak's progress on a wider baffle bottom.

Peter
[/quoteHey SJ, wanted to check up on the build, I still have not started but , I am definetly gonna go
with the Dayton 15 on the bottom and everything else in line with original (awesome) design.

[matevana]

One interesting permutation of the Hestia design is to swap the location of the LF and Mid drivers to produce a more forward sounding and prominent mid range. The Dayton's slightly higher efficiency may also be a better choice for those looking to drive the Hestia with a SET amp. (Overall efficiency raises to about 92dB)

Without a crossover mod, the Dayton Pro Sound driver sounds too proud as a dedicated mid range within the context of this project. The mod referenced below provides a notch in addition to addressing a rising impedance condition which may otherwise be an issue for tube amps.

I now have two sets of Hestias configured each way... Both sound great but with slightly different tonal characteristics. The cool thing is you can try both options without having to change drivers or baffles, for just a few bucks in reisitors and caps.

[sjhomey]

Hi Squid
I'm working on the permanent baffles, flush mounting the drivers, so lots of router work. I am moving the tweeter/midrange combo higher on a taller baffle to get them closer to ear level. In the meantime they sound sweet on the test baffles. You are going to like them.

Peter

[LynX]

Hello everyone, I am new here.
I was just browsing to see if anyone else had done a project with these drivers from MCM.
Glad to see it was an OB design as well. The Hestia project caught my attention as I have a pair of speakers currently using the 55-2981 drivers but for the low end in a very large ported box with the mid being OB.
I was contemplating about using the driver for mid purposes as well in a OB replacing the current top I have. When I saw this It got me thinking it might actually be probable. I would however need to make the baffle larger on top but still make it look nice.
heres a pic of the project while being constructed still.



also the bullet driver has been replaced with a Vifa dome (don't have the number off hand but I know it was used in the orient express by Zaph Audio). As I had not liked the sound/ harshness of the bullet.
The project is crossed currently with a cx3400 but hoping to swap that out soon with a dbx or digital unit as the current active crossover has some quality issues.
I am really interested in using a plate amplifier with these if I converted it to a half passive/active setup. With the top being the top half Hestia design. Thinking about using the PSC2.400 by hyphex.
any questions comments or concerns please inquire.

I would also like to note that the drivers from MCM have changed to a different model/design. The RMS is lower the cast frame slightly different and the paper cone almost looks identical to the Dayton shown here. I have
no idea how these sound as I have not tried or tested them in any way. Just a heads up.

[matevana]

Hi Lynx,

Thanks for sharing your design. Some similarities between what you have done (and want to do) and the Hestia. I havent had a chance to hear the Hypex plate amps but understand they are nice. I've been very favorably impressed with the Yung models sold be PE. I have moved that to the top of my list, previously reserved for the Bash amps. The Yung are at a slightly lower price point and appear to have the edge on quality as well. I am on the fence between models with and without boost for OB. This may depend on the particular driver more than anything else, but a switchable boost would be a nice feature.

Completely agree with you about quality issues with several Behringer crossovers. I've played with many over the years and really like the dBX 223 and 233 series, as well as most of the models by Ashly. Not completely sold on the Driverack models, or many other all digital x/o's for that matter.   

I've been talking to someone on another site who is building a slot loaded open baffle sub using 6 of the MCM select drivers. He bought both the 10's and 12's. His order for the 12's were mixed, both old and new, while the 10's were all original, the same used in the Hestia. He said the thickness of the cast frame has been reduced on the new drivers (i.e., cheaper) but the T-S parameters were similar. The cone design has also been updated. Hasn't had a chance to do much more than  test them at this point. 

[LynX]

Those Yung amps seem to get a lot of good reviews. I like the power output and lightweight. Will most likely go with this route as it seems to be the cheapest method to get good quality bass amplification. So which one would be better for this project. The one with 0db boost or 6db? Another question would be how I should hook up the signal. A lot of my current setup is pro audio oriented. PC to Sound interface (presonus audiobox) to mixer, to behri dsp1424 (to limit noise/gains/hard limiter), to EQ (room correction/other) to active crossover, to amplifiers (1 of which I don't like). Should I hook the plate amplifiers after the crossover (is the crossover in the yung disable able?) or would this be to much input voltage? Or hook from the sound interface before mixer?
Might have been a lot easier if I hadn't given my dad my old Newcastle 965r.

The Hestia designs seems to be for relaxing on the couch listening to music or watching cinema where as mine currently are for standing walking around/party. As the tweeters are at standing level.
As far as the speaker is concerned is the 15" baffle necessary? Currently the baffle is at 12" but putting some molding or reworking the baffle all together shouldn't prove to difficult. I would have to have a new baffle anyway for a offset tweeter in the design anyway. My router died on me leaving me with just my rotozip and its circle cutter (so no driver sinking T_T) I know that it makes a huge difference for tweeters but what about mids and woofers?
Also I hope the new driver style sounds the same as the current ones because I'm very impressed with them. When I first tried the originals out they sounded far from appealing. But after playing them it warms my heart sometimes knowing that I just bought those for 25 a piece. Breaking these in are a must, Spectacular.

If anyone wants I can post a pic of the new cone style.

I would love to hear the slot loaded sub project also.

[matevana]

Those Yung amps seem to get a lot of good reviews. I like the power output and lightweight. Will most likely go with this route as it seems to be the cheapest method to get good quality bass amplification. So which one would be better for this project. The one with 0db boost or 6db? Another question would be how I should hook up the signal. A lot of my current setup is pro audio oriented. PC to Sound interface (presonus audiobox) to mixer, to behri dsp1424 (to limit noise/gains/hard limiter), to EQ (room correction/other) to active crossover, to amplifiers (1 of which I don't like). Should I hook the plate amplifiers after the crossover (is the crossover in the yung disable able?) or would this be to much input voltage? Or hook from the sound interface before mixer?
Might have been a lot easier if I hadn't given my dad my old Newcastle 965r.

The Hestia designs seems to be for relaxing on the couch listening to music or watching cinema where as mine currently are for standing walking around/party. As the tweeters are at standing level.
As far as the speaker is concerned is the 15" baffle necessary? Currently the baffle is at 12" but putting some molding or reworking the baffle all together shouldn't prove to difficult. I would have to have a new baffle anyway for a offset tweeter in the design anyway. My router died on me leaving me with just my rotozip and its circle cutter (so no driver sinking T_T) I know that it makes a huge difference for tweeters but what about mids and woofers?
Also I hope the new driver style sounds the same as the current ones because I'm very impressed with them. When I first tried the originals out they sounded far from appealing. But after playing them it warms my heart sometimes knowing that I just bought those for 25 a piece. Breaking these in are a must, Spectacular.

If anyone wants I can post a pic of the new cone style.

I would love to hear the slot loaded sub project also.

My recommendation on the Yung amps would be as follows: If you get the 200 watt amp, I would opt for the bass boost.  If you get the 300 watt amp, it's a toss-up, but I might opt for the one w/o boost. Regarding making the connection, I'm a big fan of less is more. I split the output from my CD player with a high quality RCA male to 2 RCA female adapter. Then run one cable to my amp and another to the subwoofer amp. That's it!  Amazing how good it sounds when it's such a direct connection; no preamp, no miles of circuits and grounding points to degrade the signal, especially in the analog stage.

The 15" baffle width is critical to the design, as the crossover has been voiced to work with these dimensions.  You can add wings to the back of a 12" panel, to get the rough equivalence of a 15" flat panel. In this design, I wouldn't worry too much about countersinking the woofer or midwoofer; it's always best to flush mount the tweeter as you have pointed out. I angle my Hestia back about 10 degrees, which provides good interaction at the seated distance in my set-up. Most critical is planting the woofer as close to the floor as possible; the midwoofer and tweeter can be raised if you like; just remember to keep the relative distance between those two drivers the same.

[sjhomey]

Finished up a set of Hestias about a week ago. They sound great. I flush mounted the drivers which took quite a bit of router time, but overall a straight forward project. Also, I moved the mid/tweeter combo higher on a taller baffle closer to ear level. The sound between the HF and LF is very cohesive despite the gap in between.

Matevana if it is not akin to asking the alchemist how he makes gold, would you mind describing the process you went through to design the crossover?

And also, what's next?

[Plund]

SJHomey,

Nice build!  I hear you saying there is plenty of bass...how large is your listening area?  You don't feel a need to augment with a subwoofer?  I almost ordered drivers/plate-amp/components for the Hestia last week, but decided I really need to finish my Frugal-horn build first.  My speaker building has slowed to crawl while my wife and I get situated in a new home. 

Pete

[Poultrygeist]

Since they're on sale now for $99 each I purchased a pair of Yung 300 plate amps. These class d amps extract some nice tight bass from the Alphas. They're compact, very powerful and produce little heat. I couldn't be more satisfied. I opted for ones without bass boost.

[LynX]

I really want those yung amps.. at 99 for the 300w model i am very tempted but alas my funds are limited atm. Argh! Also are those the visaton fullranges you have there poultry? interesting looking setup with the plate amps boxed like that on the shelf. Personally i think i would put in on the base of the speaker somehow so it can walk around with where i place the speaker. but you would need long reference cables. so what you have there looks like a pretty sucessful and inexpensive subwoofer set top amplifiers.

Also great job Sjholmey. Those look great... very bright red though

[sjhomey]

Thanks for the compliments. I found some edge glued panels of three or four inch boards at one of the big boxes. The wood wasn't special but I liked the patten of the boards and I wanted them to pop a little. The idea was to stain the panels and then finish with a high gloss. But they came out basically red. They aren't as red as the photos show, but when the lights are low and the tunes are playing its all good.
I haven't lived with a subwoofer. The Yung amp can make the floor shake, but of course that isn't the same as LF extension. I have a sub box half built in the shop so maybe I'll have to get that finished.

[Poultrygeist]

I've tried subs with my Alphas in flat baffles and in H-frames and IMO they detract more than they add. I guess I have a problem with how a sealed sub loads a room. To me it's not natural. The Alphas may not be everyone's choice but I like their bass weight and fast transients. The Yung class D amps add detail I wasn't getting with SS amps. I listen to mostly jazz and I'm hearing more wood and string resonance when bass players use that "slap style"of picking.

[matevana]

I've tried subs with my Alphas in flat baffles and in H-frames and IMO they detract more than they add. I guess I have a problem with how a sealed sub loads a room. To me it's not natural. The Alphas may not be everyone's choice but I like their bass weight and fast transients. The Yung class D amps add detail I wasn't getting with SS amps. I listen to mostly jazz and I'm hearing more wood and string resonance when bass players use that "slap style"of picking.

Completely agree with Poultry here. Unless you cross to a sub very low there seems to me something disjointed in merging flat panels with separate sub enclosures. Perhaps it's a phase or time alignment issue, (or both) but what sounds OK initially eventually leads to dissatisfaction when you listen critically. I spent countless hours with digital delays and really wasn't able to make up for this effect. I've practically abandoned the idea now, in favor of locating all of the drivers on the same approximate plane. I do like attempting to alter the plane slightly to better align the driver's acoustic centers, but that's all.