Hi guys, I have acquired 2 nearly new panels from a Martin Logan Quest with both 12" woofers and power supplies and I was planning on making my own woofer enclosures and frames. I was planning on building a passive crossover for the ESL panel using the original schematics and then using one or more pro audio DSP amps for the woofers depending on the orientation. I currently have a set of Aeries I speakers that are powered this way and the results have been fantastic. I see the newer models use a pair of woofers per speaker in a push-push configuration with DSP on the rear firing woofer.
I am wondering if I should design these with rear firing woofers as well? Since the bass sections will be ran in an active configuration I'm not really tied to using the original woofers, I would likely stay with sealed boxes for the sake of simplicity. I am asking this question because I am new to speaker building outside of some sealed and ported subwoofers I have made in the past and I don't want to go down a path that makes these very difficult to design/integrate. I am very good at mechanical design and fabrication as that's part of what I do for a living, but not so much speaker design.
I have only just started design work so I am not really tied to any one configuration. Any advise is much appreciated!
I am wondering if I should design these with rear firing woofers as well? Since the bass sections will be ran in an active configuration I'm not really tied to using the original woofers, I would likely stay with sealed boxes for the sake of simplicity. I am asking this question because I am new to speaker building outside of some sealed and ported subwoofers I have made in the past and I don't want to go down a path that makes these very difficult to design/integrate. I am very good at mechanical design and fabrication as that's part of what I do for a living, but not so much speaker design.
I have only just started design work so I am not really tied to any one configuration. Any advise is much appreciated!
Make them totally separate and have the ESL sit on 4 posts which straddle the woofer cabinet with no physical contact.
ML should make a 'BYOB' ESL panel like that!
ML should make a 'BYOB' ESL panel like that!
That actually what I was planning on doing, I just didn't draw it. I thought it might be useful to be able to slide the woofer forward or backward seperate from the panel.
Time alignment and vibrations kept off the esl panels. Woofers should be well in front of the esl line source
You see this mess in Martin Logan impulse response tests. More concerned with looks than performance
A dual setup at least keeps some vibrations to a minium. If you can electronically move the phase into alignment
then you would be well ahead of the game
You see this mess in Martin Logan impulse response tests. More concerned with looks than performance
A dual setup at least keeps some vibrations to a minium. If you can electronically move the phase into alignment
then you would be well ahead of the game
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I was probably going to use the time alignment feature on some of the Crown pro amplifiers. It wouldn't be hard at all to move the enclosure forward as I'd likely have the position adjustable.
It's an ESL hybrid commercial offering from member Capaciti and appears to have 7 inch woofers. Must be getting on 12-15 years old now? Maybe you can find more about it?
I'm definitely going to look into it, it's a very interesting design. It's not what I had in mind but maybe it has some advantages over the convention hybrid designs. It's also easy to build and space efficient so that's awesome.
Might be worth having a think about what the pressure wave created by a box woofer powered by hundreds of watts positioned under an ESL out of planar alignment, can do to the ESL Mylar membrane. Try suspending an A4 paper sheet in front of a sub for a visual indicator
https://www.diyaudio.com/community/threads/two-way-active-esl-dynamic-line-array.324345/post-5481957
@Calvin Purist speakers are gorgeous:
The @Calvin design cunningly positions the ESL in the equipressure zone of the woofer tower. There are multiple other clever design reasons for this woofer array and there are also the inevitable compromises. Its worth working those out before selecting drivers. Loads of info on this forum with other threads.
Hi,
I´m flattered to see my designs beeing liked so well still after so many years 😎
You can find infos on my personal website also.
Both, the 8-woofer ESLmk2, as well as the smaller 6-woofer eslmk2 designs are mine in fullness.
The woofers are indeed 7" drivers of medium Q, medium Fs and long stroke (within their size class).
Crossed overactively and well, I couldn´t detect much differences when varying Bass-tower against ESL-panel position.
Varying the x-over frequency had much more impact on the outcome.
Changing the discrete analog active X-over to a digital SpeakerManagementSystem (SMS) improved the system measurements clearly, but remained sonically less involving -in acoustically ok surroundings. Digital gained the lead though in unfavourable surroundings.
The DACs of the SMS proved to be the eye of the needle.
With a new multichannel DAC and the accourate software running on our music servers (running filtering and room correction on the fly while working as music server) sonics improved and lifted the system to a extremely high level of authenticity and lifelike experience.
".....but maybe it has some advantages over the convention hybrid designs."
Of course has it it´s advantages 😉
The conventional designs show a stark variation in distribution character between panel and woofer section.
This becomes audible in a way as if the woofers sound slow and lagging, leading to the wrong myth that ´hybrids can´t work properly ... lightweight film and heavy paper don´t match!´
Also the SPL over distance relationship differs.
You can´t solve that problem electronically in the crossover ... You have to tackle it mechanically.
At least +- one octave around the x-over point should the distribution characters be similar and/or softly transiting into each other.
Placing dipolar woofer tower and ESL panel side by side solves the distribution and SPL problems, but may lead to comb filter effects in the horizontal when x-overed too high.
Crossed over low enough -when wavelengths are still large- the concept of dipolar woofer tower and tall ESL panel is probabely the concept of lowest possible compromise though.
jauu
Calvin
@Andersonix: Capaciti -whom I respect as one of the most ESL knowledgeable and truely nice guy- afair never commercialized such a hybrid design, certainly not in that quality of manufacture, though he tested the concept at least in private.
I´m flattered to see my designs beeing liked so well still after so many years 😎
You can find infos on my personal website also.
Both, the 8-woofer ESLmk2, as well as the smaller 6-woofer eslmk2 designs are mine in fullness.
The woofers are indeed 7" drivers of medium Q, medium Fs and long stroke (within their size class).
Crossed overactively and well, I couldn´t detect much differences when varying Bass-tower against ESL-panel position.
Varying the x-over frequency had much more impact on the outcome.
Changing the discrete analog active X-over to a digital SpeakerManagementSystem (SMS) improved the system measurements clearly, but remained sonically less involving -in acoustically ok surroundings. Digital gained the lead though in unfavourable surroundings.
The DACs of the SMS proved to be the eye of the needle.
With a new multichannel DAC and the accourate software running on our music servers (running filtering and room correction on the fly while working as music server) sonics improved and lifted the system to a extremely high level of authenticity and lifelike experience.
".....but maybe it has some advantages over the convention hybrid designs."
Of course has it it´s advantages 😉
The conventional designs show a stark variation in distribution character between panel and woofer section.
This becomes audible in a way as if the woofers sound slow and lagging, leading to the wrong myth that ´hybrids can´t work properly ... lightweight film and heavy paper don´t match!´
Also the SPL over distance relationship differs.
You can´t solve that problem electronically in the crossover ... You have to tackle it mechanically.
At least +- one octave around the x-over point should the distribution characters be similar and/or softly transiting into each other.
Placing dipolar woofer tower and ESL panel side by side solves the distribution and SPL problems, but may lead to comb filter effects in the horizontal when x-overed too high.
Crossed over low enough -when wavelengths are still large- the concept of dipolar woofer tower and tall ESL panel is probabely the concept of lowest possible compromise though.
jauu
Calvin
@Andersonix: Capaciti -whom I respect as one of the most ESL knowledgeable and truely nice guy- afair never commercialized such a hybrid design, certainly not in that quality of manufacture, though he tested the concept at least in private.
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Interesting. What might be an upper crossover frequency to aim for roughly? The ML panels can sound thin to some and might benefit from woofer help up to maybe 300Hz = 114cm wavelength to fill in the lower mids. Is that too high?
'
Whats best for the woofer tower: Dipolar / Bipolar / Sealed Box / Open Baffle ?
Please dont let reality get in the way of good theory 🙂 Besides it looks "right"
Tanks a lot for all the information Calvin, very interesting stuff on your website. I'll have to look into it in more detail when I get a chance.
I've built lots of sealed and ported enclosures but never anything open baffle. Would this behave similarly with a sealed enclosure? Also I had heard that driving ESL panels without passive crossovers would cause most amplifiers to oscillate?
I've built lots of sealed and ported enclosures but never anything open baffle. Would this behave similarly with a sealed enclosure? Also I had heard that driving ESL panels without passive crossovers would cause most amplifiers to oscillate?
Hi,
afair ML used a 12u thick ITO sputtered standard off-the-shelf film and stretched it extremely tight without heat treatment.
This lead to a high fs, which sank considerably during a rather long break-in period.
Over this period the speakers were kind of 'detuned'.
Fresh out of the box a ML could indeed sound thin.
ML also utilized rather high xover frequencies even with their large wide panels.
Around 400Hz our hearing is very sensitive and I preferred to keep this range free from xover artefacts.
Its also a range where dimensions/wavelengths become increasingly critical for the acoustic output.
Crossing around 300Hz could be ok, if bass tower and panel are close enough and of small enough width.
If the speaker is a highly directive concept where You expect the listener to listen from a single fixed position a higher xover frequency and hence more prominent comb filter efects might be tolerable.
In the end You need to test what compromise suits Your requirements the best.
The same applies to the Q which bass tower concept is the best.
The dipolar distribution character of the panel is best matched to a dipolar distributing partner, yes.
But that is just one single aspect.
A dipolar bass sounds very different to a monopolar or bipolar one.
Typically it sounds very precise with less boom, and a fast snappy kickbass.
A sonic character that mates well with ESL panels.
It lacks though on the slam and authority in the low register we are used to.
The larger Your listening room the more difficult it gets to 'fill' the room sufficiently.
A dedicated (monopolar) subwoofer is then required to make the system 'complete'.
A monopolar bass tower could in the end be a better overall compromise even if it matches the panel less well.
Driving a ESL via active or passive Xover makes a difference for the amp behaviour.
The passive parts may indeed reduce the phase shift of the panel in the upper midrange, which presents a serious problem to many amp's stability.
But then ... only use good and stable amps in first place 😉
jauu
Calvin
afair ML used a 12u thick ITO sputtered standard off-the-shelf film and stretched it extremely tight without heat treatment.
This lead to a high fs, which sank considerably during a rather long break-in period.
Over this period the speakers were kind of 'detuned'.
Fresh out of the box a ML could indeed sound thin.
ML also utilized rather high xover frequencies even with their large wide panels.
Around 400Hz our hearing is very sensitive and I preferred to keep this range free from xover artefacts.
Its also a range where dimensions/wavelengths become increasingly critical for the acoustic output.
Crossing around 300Hz could be ok, if bass tower and panel are close enough and of small enough width.
If the speaker is a highly directive concept where You expect the listener to listen from a single fixed position a higher xover frequency and hence more prominent comb filter efects might be tolerable.
In the end You need to test what compromise suits Your requirements the best.
The same applies to the Q which bass tower concept is the best.
The dipolar distribution character of the panel is best matched to a dipolar distributing partner, yes.
But that is just one single aspect.
A dipolar bass sounds very different to a monopolar or bipolar one.
Typically it sounds very precise with less boom, and a fast snappy kickbass.
A sonic character that mates well with ESL panels.
It lacks though on the slam and authority in the low register we are used to.
The larger Your listening room the more difficult it gets to 'fill' the room sufficiently.
A dedicated (monopolar) subwoofer is then required to make the system 'complete'.
A monopolar bass tower could in the end be a better overall compromise even if it matches the panel less well.
Driving a ESL via active or passive Xover makes a difference for the amp behaviour.
The passive parts may indeed reduce the phase shift of the panel in the upper midrange, which presents a serious problem to many amp's stability.
But then ... only use good and stable amps in first place 😉
jauu
Calvin
Doing some quick sketches in Draftsight, it looks like I could do 4 10" woofers on per speaker and that would nicely match the height of the 48" X 12" ESL panel.
For crossovers I was thinking of keeping it simple to start and doing a copy of the stock passive highpass at 150HZ on the panel, same as factory. For the woofer tower I would use adjustable electronic crossovers/DSP and a sealed enclosure.
For crossovers I was thinking of keeping it simple to start and doing a copy of the stock passive highpass at 150HZ on the panel, same as factory. For the woofer tower I would use adjustable electronic crossovers/DSP and a sealed enclosure.
After many, many delays, this project is starting to go somewhere. Life got in the way and the laser cutter botched the first batch of parts. I
have the panels roughly fitted in the frames but the retaining brackets could use some additional work as the fitment is pretty bad.
I'm not sure what I'm doing for the bass section as of yet, I'm less excited about making an expensive tower of woofers as vet bills have recently destroyed my bank account. More to come in time.
have the panels roughly fitted in the frames but the retaining brackets could use some additional work as the fitment is pretty bad.
I'm not sure what I'm doing for the bass section as of yet, I'm less excited about making an expensive tower of woofers as vet bills have recently destroyed my bank account. More to come in time.
I just happened to open this thread today. Sorry about vet bills...
Since you have great experience with monopole subwoofers, and obviously have some, why not just use dsp like minidsp 2x4HD to start trying different crossover settings and placement. M&L concept is good but dsp will really make it work right! Stereo SW is needed to be able to set xo up to 200Hz, and delay adjustment is needed to avoid nulls.
Dipole subs are difficult to get working in mid/small rooms (might work well in your hall) and I actually haven't even tried them. Closed box SW sounds very good, but settings with dsp take lot of time and measurements.
My diy project here https://www.diyaudio.com/community/threads/aino-gradient-a-collaborative-speaker-project.231353/
Google album https://photos.app.goo.gl/9qtxDZfZYhda3L5fA
Since you have great experience with monopole subwoofers, and obviously have some, why not just use dsp like minidsp 2x4HD to start trying different crossover settings and placement. M&L concept is good but dsp will really make it work right! Stereo SW is needed to be able to set xo up to 200Hz, and delay adjustment is needed to avoid nulls.
Dipole subs are difficult to get working in mid/small rooms (might work well in your hall) and I actually haven't even tried them. Closed box SW sounds very good, but settings with dsp take lot of time and measurements.
My diy project here https://www.diyaudio.com/community/threads/aino-gradient-a-collaborative-speaker-project.231353/
Google album https://photos.app.goo.gl/9qtxDZfZYhda3L5fA