[JohnCZ]

Hi Ed,
I looked at the DBX 223 crossover and it would be a perfect tool if it offered varying slopes - at least 12db per octave. Not able to use it though in my current configuration since I'm using an integrated without pre outs.

You stated that you prefer using a second order filter (on the bass) rather than just an amp with an adjustable cutoff frequency - such as a plate amp. Wondering if this is possible. I originally was going to employ a couple of plate amps to drive the bass but decided to use the second order filters instead.

Since the plate amps (or any amp with a cut off frequency) only limits the frequency, would it be possible to use the plate amp set at a certain frequency - ie: 100hz - and also use a cap at the driver to complete the second order part of the filter?

Can I also assume that you can use a plate amp set at its highest maximum frequency cutoff ie:150hz but still use a second order filter (cap and a coil) on the bass set to 100hz?

With all the products available to speaker building hobbyist it surprising there is not a source for flexible electronic crossovers at a reasonable price.

Thanks for your help and support for us frustrated open bafflest.
John

[matevana]

Hi John,

Most plate amplifiers that have an adjustable electronic low pass filter, use a 12 dB per octave slope. In many cases this is all you will need. If you can get one with a variable phase control, and not just a phase reversal switch, this is often very helpful. Getting the phase right can be key to a good integration.

You can always attempt to increase the slope by adding passive filters, separate from the line level filtration in the plate amp. I did some experimenting with this in an earlier project, but in many cases this is not needed.

The Yung plate Amps are a good example of variable phase capabilities.  I find this helpful in OB woofer integration, since you can correct some phase anomalies that occur as a result of the reflected low frequencies. This often takes a bit of trial and error, especially if you don't have a good measurement system.

Ed

[sjhomey]

Hi Ed

Long time no post.

However, I have been listening to my Hestia SLs for several hours every evening for the last couple of years and enjoying them very much.

I've kept the thought of building the Hestia V, probably the dome version, on the back burner for some time now. My question to you is how much of an upgrade would the V be from the SLs? I hope that is not an unfair question. I'm just wondering if it is worth the investment of funds and time.

Thanks.
Peter

[matevana]

Hey Peter!

Good to hear from you and glad you're still enjoying the SL's. These things are always subjective and I no longer own the SL's, but I do remember the V's being a fairly big step up when I first built them. I currently own one set of V's with the Dayton AMTPRO tweeters and one set of V Domes's with the Vifa Dual Ring Radiator tweeters. Both are good in their own right. You might also find the separate H/Frame U/Frame lower cabs to be an advantage as well. This allows construction of a separate bridge to minimize vibration transference from the bass driver. The Seas 3" mids (used by Linkwitz) are also really articulate and natural. I've relegated the Eminence bass-guitar speaker to bass duty in the lower cabs (where they excel), and use both Usher and Peerless 10" drivers for the lower mid units. The crossovers have since been tweaked as a result of this change. 

If you are looking for a project to get into, I highly recommend either as the next generation. If you're ever in FL, I would be glad to demo them for you as well.

Ed

[sjhomey]

Ed, thanks for getting back to me so quickly as usual. I need to do some research but want to make sure I have the driver models correctly. Do I have these right?

Tymphany XT19TD00-04 3/4" Dual Radiator Tweeter

Seas Prestige FU10RB H1600-08 4" Full Range ( you mentioned 3" in your post, but I think you mean these, no?)

The 8" Ushers I used in the SLs are no longer available. Parts Express offers both of the following. Are one of these the Ushers you are using for the lower mids?
     Usher 8945A 7" Carbon Fiber/Paper Woofer
     Usher 8137A 8" Kevlar/Carbon Fiber Woofer (rather unattractive yellow)

Which 10" Peerless are you using? I very much like the Ushers I am using. Do you have a preference between the Ushers and the Peerless?

Eminence Legend B102 10" Bass Guitar Speaker 200W 8 Ohm

Thanks
Peter

[drmike]

does melby still offer these flat packs?
thanks,
drmike

[matevana]

The tweets are the XT19's, the mids are FU10's (Seas calls them 4" but their cone surface is actually < 3") and the lower mids are either Usher 1001B's or Peerless SLS-10's. You can also use the Linkwitz version of the mids (Seas MU10RB-SL) with a small component change. I have one system using the FU10's and another using the MU10RB's and they are extremely close sonically.  The Eminence drivers are in fact the B102's.

Regarding the B102's, I have one with the whizzer cones removed and replaced with oversized dust caps and another w/the whizzer cones in tact. Even when used as a bass driver in the H-frames, there is a noticeable difference as to how high they will play. I like them both and really cant say which pair integrates better overall. This was more of an experiment than anything else when they were initially used in the top section.

[matevana]

does melby still offer these flat packs?
thanks,
drmike

I believe he does. Haven't worked with him since the two designs were released. He does good work and is very reasonable.

[sjhomey]

Hi Ed

I hope you will notice this post. Its been two years since I last posted here and I am just now putting this project together. Time flies. I have several questions to run by you before I start construction.

I intend to use the following,
XT19TD00-04 4 ohm tweeter
Seas MU10RB-SL-04 4 ohm fullrange
Peerless 830668 10" 8 ohm low midrange
Eminence Legend B102 10" 8 ohm in WayBasic H cabinets

Would you tell me what your final crossover components are for this setup? I think you made some changes over time and may have changed components.

You have used the WayBasic cubes for the H frame enclosures for some time now. How are they holding up? Reviews on Amazon are somewhat mixed with some complaints of the adhesive not lasting and the cubes falling apart. I would imagine a big chunk of MDF in the center would stiffen and make for a stronger structure. Do you still recommend them?

As for the baffles, you designed them on the Hestia SLs tilting backwards some. I believe that was to make the voice coils of the various drivers line up in the vertical plane. You didn't do that on the forte or the V designs as far as I can see. Do I have your reasoning right and did you decide it wasn't critical?
Also, I noticed at post 19 on the New Build:Hestia V thread your explanation of your decision to rear mount the Seas and the Peerless. Flipping the baffles around and front mounting would provide a fairly substantial roundover on the back side and more closely align the voice coils on the Melby c&c baffles if that is significant. I'm not suggesting a change just wondering what your thoughts are.

I hope you are well and still designing.

Peter

[matevana]

Hey Peter.

Long time!  Good to see you're still in the hobby. I no longer have the Hestia V's; I often sell components to help fund the next project.

I tried to address your questions below.  Let me know if you'd like to discuss some more.



Q) Would you tell me what your final crossover components are for this setup? I think you made some changes over time and may have changed components.

A) If memory serves, I only played with the attenuation level of the MU10RB midrange driver, going from the original 15 ohm value to 22 ohms instead. I was also level matching to the Eminence B102 which made up the lower driver on the baffle at the time.

Q) You have used the WayBasic cubes for the H frame enclosures for some time now. How are they holding up?

A) I had no issues with them. The baffle was made of ¾” ply and served to help keep the shell intact. I used construction adhesive on the inside sealing the baffle to the cabinet walls in addition to the Way Basic adhesive strip. Also note that when you orient the cube, the top/bottom is different from the sides. It’s important to make sure it rests on its bottom and not one of the sides. This concept only works (compressed cardboard) due to the absence of any real air pressure inside an H frame. The Way Basics cube really just served to delay the back wave, but the baffle itself was the key structural part.   

Q) As for the baffles, you designed them on the Hestia SLs tilting backwards some. I believe that was to make the voice coils of the various drivers line up in the vertical plane. You didn't do that on the forte or the V designs as far as I can see. Do I have your reasoning right and did you decide it wasn't critical?

A) Yes correct. Quite frankly, it’s hard enough getting a reasonable outcome from a 3 or 4 way design, that concepts like ‘aligning a driver’s acoustic center’ often get kicked down the road. Your observation seems right; inverting them may better serve the vertical alignment.   

[sjhomey]

Thank you Ed

Regarding the components, which might not be easy an answer since you no longer have the speakers and given the time since you built them, I'm not quite sure what they should be. You listed the following earlier in the thread.

Eminence B102...............9.00 mH 15 AWG Sledge Hammer Inductor (series)
Seas MU10RB-SL.............Mundorf 15 ohm MOX metal oxide film resistor (series)
Vifa XT19.........................Mundorf  1.5 uF EVO Oil capacitor (series)

I'll be using the Peerless for the lower midrange and the Eminence will be down in the WayBasics.

Would you recommend the components and values as listed above?

You also mentioned the following.

"There is also a 10 ohm shunt resistor placed across the two auxiliary terminals (in parallel) of the Eminence B102. Here too I am using the Mundorf MOX brand. This is a critical part of the woofer integration. Without it there is too much high frequency overlap from the B102.  The resistance across the terminals helps the large inductor track better and chokes at least one additional octave of high frequency information. In this alignment the Eminence B102 reinforces the lower octaves of the MU10's range and it sounds like one coherent driver." 

Would that 10 ohm shunt resistor be valid on the Peerless?

I will change the value of the resistor on the MU10s from 15 to 22 ohms.

I know that much of the magic happens at the crossover level and in this case modifying drivers outputs, but it is beyond my abilities so I plead ignorance and ask for your help.

Thanks
Peter

[matevana]

Be glad to help. First a few questions. Why did you decide to move the Eminence to sub duty and make the Peerless the lower mid? Also, can I assume the H frame will be powered by a plate amp with its own adjustable crossover?

The Eminence is at least 5dB louder and it’s TS parameters are quite a bit different. Not a bad thing, but the crossover will require some changes. The Peerless has better extension on the low end; the Eminence better on the top. All of these things are workable however.

[sjhomey]

Ed, I apologize for asking you to revisit a design from several years ago. In post #43 above you wrote ' I've relegated the Eminence bass-guitar speaker to bass duty in the lower cabs (where they excel), and use both Usher and Peerless 10" drivers for the lower mid units. The crossovers have since been tweaked as a result of this change.'

That is what made me plan to switch those two drivers and to ask what crossover changes you made. I am not so far along that I can not switch back again if you think the original setup sounds better.

Thanks
Peter

[matevana]

Thanks Peter. I actually didn't remember that. I had the Usher 10" drivers in the lower mid position for a short time, before someone approached me about buying the V's. The Peerless 10" SLS has very similar parameters to the Usher 10", so let me see if I can find any notes about the component values used. Is it OK to PM you with further info?     

[sjhomey]

Sure Ed that would be fine. Sorry to put you to the trouble.

[calupi]

Hi Ed,
I like your project Hestia V & Dome for his simplicity and low cost.
I'm looking  for a good substitute of my omnis speakers.
I bought Lxmini plans already, after that I discovered a lot of other project I'm curious about.
I saw best projects are 4 way and eventually not much more expensive than Lxmini.
But...my room is small: 4.5m x 3.75m x 3m.
My speakers position is along the long wall.
Lx521 and Nao are for bigger rooms.
How far  should be Hestia from front and side walls and to sweet spot?
How they perform with big orchestras, symphonies and operas (vocals).
Any advice?
In any case, congrats for your valuable design.
Thank you!
carlo

[matevana]

Hi Calupi,

Sorry for the delayed response but I have been busy with Work. The Hestia V and V-Dome will require similar breathing space as most full size systems; it's really just physics. In a pinch you could try a half meter from the front wall, but 1 M is generally best.

For the past 2 years I have come around to the full range camp (the dark side). While there are definite limitations such as high intermodulation distortion and limits on maximum volume, there is something about the lack of phase abnormalities that MOST crossovers seem to suffer from. A good 3 or 4 way design, such as the two examples you mentioned, can be very difficult to achieve. My current designs are centered around a well made full range driver, a reasonably sized baffle elevated to ear level, and a well integrated sealed or aperiodically damped woofer. I have been very happy with these designs for longer than I have with any multi-way OB system. I never thought I'd find myself agreeing with FullRangeMan, but as I get older he seems to be getting smarter!