@ brandon3212276
I have been reading your excellent description on your Aerius mod a few times.
I did the re-capping modification on the x-over a few years ago which brought more clarity to the sound stage.
I would like to do the Bracing mod.
Would you mind describing if your Bracing made an audible difference to the Bass response / firming up the Bass?
If anyone else have done cabinet bracing on passive MLs, you are of cause more than welcome to comment on the question above.
I have been reading your excellent description on your Aerius mod a few times.
I did the re-capping modification on the x-over a few years ago which brought more clarity to the sound stage.
I would like to do the Bracing mod.
Would you mind describing if your Bracing made an audible difference to the Bass response / firming up the Bass?
If anyone else have done cabinet bracing on passive MLs, you are of cause more than welcome to comment on the question above.
Please allow me to specify in short words what I am looking for in my thread above.
Is the bracing of passive ML Hybrid speakers like Aerius worth the work?
Does it make an audible difference?
Thank you for your help.
Is the bracing of passive ML Hybrid speakers like Aerius worth the work?
Does it make an audible difference?
Thank you for your help.
@HiFiFuchs the bracing didn't necessarily make a huge difference, changing the crossovers to active digital Xovers did make a substantial improvement though. That's where I'd spend most of my efforts, the rest is all just extra.
@brandon3212276 - thank you for your reply.
As I am a Tube purist 🙂 I am not so keen on active Xover. Would you mind telling me which active Xover you have used? Just in case I would want to try it out 😉
What I am currently trying to achieve is improving the Bass response (tightening the Bass).
There is a German company called HiFi-Zenit offering an update the the Bass Xover. As far as I understand, taking out the xover Caps and implementing a choke. The idea is to lower the Xover frequency, which is supposed amongst others to firm the Bass and make it interfere less with the panel frequency.
If anyone have experience with a such procedure, I would love to hear from you.
As I am a Tube purist 🙂 I am not so keen on active Xover. Would you mind telling me which active Xover you have used? Just in case I would want to try it out 😉
What I am currently trying to achieve is improving the Bass response (tightening the Bass).
There is a German company called HiFi-Zenit offering an update the the Bass Xover. As far as I understand, taking out the xover Caps and implementing a choke. The idea is to lower the Xover frequency, which is supposed amongst others to firm the Bass and make it interfere less with the panel frequency.
If anyone have experience with a such procedure, I would love to hear from you.
I've heard of this company and the updated bass crossover but I've never heard of anyone actually using it.
The best solution is to use an amplifier with built in active crossovers such as the new Crown XLS pro amps. Use something simple like this on the woofer and use your tubes on the panel. The passive vs active argument has been beaten to death over on the Martin Logan forums and the active solution has been shown to be better many times. Taking the load imbalance away from the tube amplifier might also help.
I use a Dayton 4X8 DSP crossover as detailed in the earlier pages of this thread.
The best solution is to use an amplifier with built in active crossovers such as the new Crown XLS pro amps. Use something simple like this on the woofer and use your tubes on the panel. The passive vs active argument has been beaten to death over on the Martin Logan forums and the active solution has been shown to be better many times. Taking the load imbalance away from the tube amplifier might also help.
I use a Dayton 4X8 DSP crossover as detailed in the earlier pages of this thread.
I took a look at the HiFi Zenit website and it looks like they're just reworking the passive bass crossover to target a lower frequency cutoff. I'm sure this is an improvement over stock but it's still only 12db/octave. I doubt it's anywhere near as good as an active Xover.
Attachments
@brandon3212276 - Thank you for taking time to look at the HiFi Zenit modification. You are right they just rework the passive Bass XO, apparently with quite some sound improvement. As I do not want to go active I am going to let them do the rework. I will write a review as soon as I have it back in the speakers.
Some years ago I upgraded parts of the XO like follows referencing the attached schematic:
Panel XO part:
C2 - 22UF swapped to a Audyn Q4 22UF
C1 and C2 bypassed with a Audyn Q4 0,1UF
C1 - 10UF Audyn Q4 was not in stock back then so I left the stock PP - 10UF in.
Bass XO part:
C4 - 100UF swapped to a Audyn Q4 100UF (quite big)
The improvement was quite audible, I was satisfied.
Today I decided to swap
the original C1 PP 10UF with a Audyn Q4 10UF
also swapped the C3 - 15UF ELECTRO to a Audyn Q4 15UF
at the same time I removed the bypass Audyn Q4 and installed a Audyn Plus 0,1UF in the same place bypassing C1 and C2
I left the Bass XO part as described above as I am going to get the HiFi Zenit Bass XO rework done.
WOW was that an improvement, I´m absolutely flabbergasted!
The soundstage turned deeper and wider and the high frequencies is far more detailed. I did not expect such a vast improvement.
Some years ago I upgraded parts of the XO like follows referencing the attached schematic:
Panel XO part:
C2 - 22UF swapped to a Audyn Q4 22UF
C1 and C2 bypassed with a Audyn Q4 0,1UF
C1 - 10UF Audyn Q4 was not in stock back then so I left the stock PP - 10UF in.
Bass XO part:
C4 - 100UF swapped to a Audyn Q4 100UF (quite big)
The improvement was quite audible, I was satisfied.
Today I decided to swap
the original C1 PP 10UF with a Audyn Q4 10UF
also swapped the C3 - 15UF ELECTRO to a Audyn Q4 15UF
at the same time I removed the bypass Audyn Q4 and installed a Audyn Plus 0,1UF in the same place bypassing C1 and C2
I left the Bass XO part as described above as I am going to get the HiFi Zenit Bass XO rework done.
WOW was that an improvement, I´m absolutely flabbergasted!
The soundstage turned deeper and wider and the high frequencies is far more detailed. I did not expect such a vast improvement.
Just think how good it would sound with no crossover 😜.
I ditched the passives years ago and never looked back.
I ditched the passives years ago and never looked back.
I know OP doesn't want to hear it, but for the rest of you: Go active xo on only the bass, and a new underworld of low, tuneful bass is revealed. Stay passive xo on just the ESL, and any amp will be happier...
You need a pretty stable amplifier to drive the panels without any crossover. My Jeff Rowland Model 1 does it fine but a lot of amps definitely won't be very happy.
I just wanted to add that a Sunfire amp can easily drive the naked ML ESL panel, including the huge Monolith III panels. Just wire the high input straight to the transformer.
Oh, and 1+ for using all-active DSP XOs makes a world of difference.
Oh, and 1+ for using all-active DSP XOs makes a world of difference.
Hi Folks I have done the high pass upgrade on my aerius i, using clarity caps. I've been quite impressed with the results, mainly I think coming from a reduction in distortion which I assume was high due to the age of the original capacitors in there.
So I think I will do the low pass as a matter of course to see if there are gains to be had there. At the moment I'm only interested in restoration so will replace the components like for like (I might look at active cross over later).
My question for you good people relates to C5. This seems to be a signal path to ground not to the output and therefore would seem a waste of money to "upgrade" the quality and a lower cost component (like the original) could be used there. C4 is in signal path and therefore may be worth spending a little more.. Or am I missing something?
So I think I will do the low pass as a matter of course to see if there are gains to be had there. At the moment I'm only interested in restoration so will replace the components like for like (I might look at active cross over later).
My question for you good people relates to C5. This seems to be a signal path to ground not to the output and therefore would seem a waste of money to "upgrade" the quality and a lower cost component (like the original) could be used there. C4 is in signal path and therefore may be worth spending a little more.. Or am I missing something?
I'm in the middle ofe doing all of this right now, bypassing the crossover and biamping with an active. From what I see, I should be able to simply run amp out put directly to the transformer (black/red & green wires currently input to transformer)?
I built a set of 2 way Electrostats during Covid using 28 JansZen panels and 2 woofers that turned out absolutely amazing sounding. Sadly last year (1/15/24) I had a fire at my place after I left for an hour and returned to a thick cloud of pitch black smoke billowing out the front door when I opened it. My Electrostats melted (all but 4 panels) and I lost tons of other speakers and gear I was getting ready to sell.
It took 11 months before I could move back in and my new speakers are the Aerius, they definitely are nothing like what I had but after living off my savings and my insurance only covered the structure I don't have cash to throw around right now. Good thing is my system is all vintage gear and it all is still working fine. A set of Heresy's I modded were right in the middle of it all and they are still working as well, cabinets got scorched and woofers needed a bit of glue on the bottom where water soaked in and the glue came loose from the cone about 1 or 2 inches on one woofer.
The Aerius really are about a tie with my Heresy's right now and I know I can get better sound out of these than what ML has tried. I spent a full year testing woofer integration with my last build.
Contrary to what everyone has been doing with hybrids, I found it I tested the panels without any restrictions and found their natural roll off (660Hz on JansZen panels) and I found woofers that had a slight dip at 700Hz, I could use a 3-way active crossover and create a 1 octave overlap (600Hz to 800Hz). By not using the mid control and leaving the crossover in 3-way mode I could control the lower and uppers to overlap.
I tried 5 different DSPs and found them all to have problems with loss of fine detail (very easy to hear with my last speakers, probably not noticable with Aerius. It's obvious that the AD/DA/AD was the problem. Not enough memory and not enough computer power to do everything and convert losslessly.
One more thing I found that played a magical role was a BBE maximizer set at flat, zero, with all controls at zero. I connected it after my dual 31 band EQ and before the crossover. What it does is corrects the phase shift and defines the midrange to "you are there" performance. I didn't need to do much tinkering with the EQ, I spent the time getting it right so it was good in my room as it was.
I just ran some sweeps today and to get these close to even it took quite a bit of sliding of bands to get something that would not hit huge peaks. You can tell instantly where you're at when that first run starts and you have to quickly run for the volume before your neighbors start to hate you.
The bass is never felt but somehow it registers on the plot. I tried 4 different 8" drivers so far and have 6 more to test. I have come to a conclusion from my previous tests, the size and shape of the cabinet will be the largest factor in how much bass you will get no matter what driver you use.
They all pretty much sounded the same and I used vastly different drivers. My last set I really wanted to use my old Mirage BP150i sub, I bypassed the amp and it was flat from 30Hz to 3KHz and mildly shook the walls at realistic levels.
The sub design is isobaric and my plan was to buy another and aim one driver towards me and the other out the back. Problem was I couldn't find a second sub to do it.
I did find a better bass set up that you felt the bass string wiggle, there was nothing missing and pinpoint in your head clear sound from 24Hz to 24KHz. They were awesome. I'm ready to build another woofer system and put it next to the panels since I know I can't get real bass from these cabinets.
The panels just don't have the definition that the 65 year old JansZens had, with the size if the Aerius panel they should easily be able to hit 370 to 420Hz without any problem. They are extremely lacking over 10KHz, they roll off at a steady rate starting at 2KHz.
Much help from the EQ brought it into acceptable range but where I used to be removing sound from the panels is now where I'm boosting it and twice as much plus all the way on up through the highest range. The JansZens needed a bit of attenuation around 5 to 8KHz and a tiny boost at 10KHz to plot a flat line.
The panels have been in Arizona their life span and I used a toothpick with a drop of water on it to see if they are dirty and I got a little bit of black on the tip after twisting it in a hole in the stator.
I'm leery of washing after reading peoples edges separated while doing it and I don't think they're dirty enough to have it be a factor.
Has anyone done it? I'm considering using some wood strips along the edges with c-grips clamping them on the edges while I rinse them off.
They amount of sound coming off them is far less than my Heresy's and my JansZens used to be even more efficient than the Herseys.
I'm really considering just running the burnt up Heresy's but I'll still have to build another bass set up since the Heresy is about on oar with the Aerius for bass!
Thanks to all that contributed to this interesting post and I'm going to get back to it now and see if I can't salvage anything worth my time from these.
The design of the ML panels is way different than the JansZen. JansZen uses push pull and ML is just push. Plus I'm positive the coloration you're hearing this due to the curved panels rear waves crossing each other before they reflect off the wall. That was part of my testing I did. I arranged the 5" x 5" JansZen panels in a curved arc and the in your head like headphones sound disappeared. I made mine all flat on the same plane as the woofer cone voice coil. 14 panels around a 10" Monitor Audio sub with another 12" infinity Kappa 7 woofer below. Both in sealed boxes, the monitor audio was in a box that barely fit the driver in it and the bass was incredible. All 4 of those woofers made it through the fire but the cabinets didn't.
I'll report back if I find anything worth reporting, I don't think MLs are going to be hanging around for much longer. Very disappointed to say the least.
@zinda it sounds like your Aerius panels are on their way out, they shouldn't be rolling off at 10K. Unfortunately it seems older Martin Logan panels are rather unreliable and some seem to last forever while other die an early death from low high frequency output. This is talked about all the time over on the Martin Logan forums.
Yeah, I have been able to get the low end working better by bypassing the crossovers on both the panels and woofers and replaced the woofers, I also removed half of the filler inside the cabinets.
I ran a sweep to see where the panels low end roll off is and found they can play down to 250Hz. I'm not sure why they're crossing them at such a high frequency when they can be used effectively to cover the entire midrange band.
Bypassing the crossovers has brought some life into them. They sound fine, basically like really good speakers should sound but they're missing that magic that an electrostat has. I'm certain that the curve of the panel is messing up the back waves reflection off the wall.
They don't have that perfect rear waves that normally will meet back up with the front wave but 1 cycle behind. But that's another point I e been thinking about for years. If the front and back waves leave 180 degrees apart, which side is the first to produce sound?
It would seem like the rear should be the 1st to leave so it can reflect back to the front and match up in sync with the front wave?
I tried experimenting with my old DIY assembled multi panel project and tried positioning the panels in a curve. Since they were only 5" x 5" (the old JansZen cabinets were made in a curved model 30 and 130) I could position them any way I chose to.
What I found was, the sound bubble disappeared when I did that. The best I could do and keep that perfect headphone effect was to aim the outermost panel (I had 4 rows tall and 5 rows wide with the woofer mounted in the center of 14 panels per side) at about a 20 degree angle towards the side wall.
That's basically how infinity mounted their smaller panels in their cabinets but failed to make mirrored sets of speakers. That was a huge mistake on their part. Without the same exact positioning on both sides, the bubble failed to exist. JansZen blocked off the back waves and I found that to be a mistake as well. That's what lead me to remove all panels from cabinets and properly assembled them. The sound was amazing and addictive.
The MLs will never be able to achieve that type of sound due to the curved panels rear waves crossing before the rear reflection.
The sound will end up coming off the rear wall in such a crazy mixed up pattern, it will end up with half of it reflecting back in between the speakers rather than off the side wall and back to you. That's what creates that huge depth and realistic sound.
Jazzman has come to this same conclusion in his full DIY builds. Even though I used small premade panels the effect will come through if they are set up correctly. The rear wall is part of the speaker and has nothing to do with low tones at all. The side wall is important as well but it's not as critical you can see up panels nearly straight forward and not have a side wall and they will form the bubble.
Typically a tiny tie in is needed to keep the rear waves from ending up in between the speakers.
What's strange is how my old heavily modified Klipsch Heresy series 1s are nearly identical sounding to the MLs (before I fixed the bass) they have a bit less off axis change in sound when you move around. I'm considering making a new speaker using the horns and assembling my old bass drivers that I used for my JansZen build. I've tried other woofers in Heresy cabinets and found there's something inherently wrong with the size and shape of those cabinets that destroys sub harmonics.
I read there's a certain shape of cabinet that has been proven to tried the most pure bass. I can't remember which maker claimed this but their stuff starts at $20k and up.
I ran a sweep to see where the panels low end roll off is and found they can play down to 250Hz. I'm not sure why they're crossing them at such a high frequency when they can be used effectively to cover the entire midrange band.
Bypassing the crossovers has brought some life into them. They sound fine, basically like really good speakers should sound but they're missing that magic that an electrostat has. I'm certain that the curve of the panel is messing up the back waves reflection off the wall.
They don't have that perfect rear waves that normally will meet back up with the front wave but 1 cycle behind. But that's another point I e been thinking about for years. If the front and back waves leave 180 degrees apart, which side is the first to produce sound?
It would seem like the rear should be the 1st to leave so it can reflect back to the front and match up in sync with the front wave?
I tried experimenting with my old DIY assembled multi panel project and tried positioning the panels in a curve. Since they were only 5" x 5" (the old JansZen cabinets were made in a curved model 30 and 130) I could position them any way I chose to.
What I found was, the sound bubble disappeared when I did that. The best I could do and keep that perfect headphone effect was to aim the outermost panel (I had 4 rows tall and 5 rows wide with the woofer mounted in the center of 14 panels per side) at about a 20 degree angle towards the side wall.
That's basically how infinity mounted their smaller panels in their cabinets but failed to make mirrored sets of speakers. That was a huge mistake on their part. Without the same exact positioning on both sides, the bubble failed to exist. JansZen blocked off the back waves and I found that to be a mistake as well. That's what lead me to remove all panels from cabinets and properly assembled them. The sound was amazing and addictive.
The MLs will never be able to achieve that type of sound due to the curved panels rear waves crossing before the rear reflection.
The sound will end up coming off the rear wall in such a crazy mixed up pattern, it will end up with half of it reflecting back in between the speakers rather than off the side wall and back to you. That's what creates that huge depth and realistic sound.
Jazzman has come to this same conclusion in his full DIY builds. Even though I used small premade panels the effect will come through if they are set up correctly. The rear wall is part of the speaker and has nothing to do with low tones at all. The side wall is important as well but it's not as critical you can see up panels nearly straight forward and not have a side wall and they will form the bubble.
Typically a tiny tie in is needed to keep the rear waves from ending up in between the speakers.
What's strange is how my old heavily modified Klipsch Heresy series 1s are nearly identical sounding to the MLs (before I fixed the bass) they have a bit less off axis change in sound when you move around. I'm considering making a new speaker using the horns and assembling my old bass drivers that I used for my JansZen build. I've tried other woofers in Heresy cabinets and found there's something inherently wrong with the size and shape of those cabinets that destroys sub harmonics.
I read there's a certain shape of cabinet that has been proven to tried the most pure bass. I can't remember which maker claimed this but their stuff starts at $20k and up.
It does sound like you're losing treble for one of two reasons - either the panels are dirty or they've lost their conductive coating.
Only one way to find out.
Wash them. There's a procedure to do it, given to me by the service rep at ML and I followed that. Basically you dismantle them from the towers and run them under a warm shower for a period of time, followed by a drying period of 24 hours.
The results were pretty staggering.
Of course, if the issue is the loss of membrane conductivity then the only remedy is to replace the panels. A pricey venture that will cost more than a decent set of used (or even new) speakers.
I have found some answers. First off the test mic I was using has an issue! I was able to find a version of my favorite RTA app called SPECTRUM RTA. The newest version won't work with my Moto stylus 5G Running And 13 but runs fine on my tablet. The version 2.10 or 2.12 is the one that runs on my phone, 2.40 is the newest.
My Moto phones have always had really good mics that are pretty close to reality when using that test app. I found the built in mic to be better than the Dayton calibrated test mic.
So I was able to run more tests and I eventually bypassed the internal crossovers and am back to active. Using a 3 way in 3 way mode. I tried the 2 way mode and even another 2 way crossover and the slope for the crossover makes for an obvious transition point.
The panels tested down to 260Hz usable output without anything crazy going on. I replaced the woofers, it appears 1 was replaced and the other has been reglued on the surround and they looked the same on the front, they were different years or something. I also removed half the fiber fill from the cab. Typically sealed cabs don't need to be packed full.
The bass has improved dramatically and the tests I have done need to be reran again just to see where I'm at. I have been swapping amps a bunch lately since I have 2 channels that get hot, I have removed those channels and tried several others in different configurations. I have 5 matching BGW A150s that can be bridged for 150w output , the 50w x2 Just isn't enough to do it and while I'm figuring out the bias settings I've subbed my old faithful Peavey CS400 with fan mod for the bass.
After tipping my the speakers down instead of upward, I have gained a huge improvement in sound quality and focus. Still not the same as the old flat panels.
I have moved them over 3 ft off the back wall and tied them so they cross in front of me while in an equal triangle set up. I'm crossed at 350Hz for the woofers the panels are running to natural roll off and I have been setting levels in the Crossover . Also finding if I need to reverse polarity on the panels or on the woofers or both!
The way the sound eminates from the panels needs to start with the rear side first (is what I would think to be logical) since it's traveling further via reflection, it should have a head start so it can meet with the front sound back in phase (somewhat).
Then theres the woofers phase, there's no way to predict if the crossover point is going to be in phase or not and using the overlap of sound could benefit front out of phase tones in the band where it would otherwise be gaining. Since the timber is different, the amount of cancellation is little but what is cancelled will help the 2 drivers transition without as much noticable change in sound.
It worked on my last set and I'm getting closer to a cohesive sound again. The mids are starting to be more directional and focused. There's a need to EQ them though there should be more mid detail in the 1kHz area. Sound like a hole there. When your speakers can reproduce that area without distortion, it becomes a huge part of realistic sounds. Increasing on other speakers just makes it sound awful and sqwauky. Where the panel will use that to bring things to life. Kinda like the opposite of what everyone used to set their 1970s eqs . The smiley face curve.
They're shaping up slowly. I've been thinking of moving the power supply into one of the side walls and using the back to mount a 2nd rear firing woofer in an isobaric config. There again comes the need to test with driver facing in or out and in phase with the front or not.
Cutting another back board to do do tests will make things easier too. I can cut 3 or 4 to have changes ready to go to mount and remove. Probably glue some blocks in the corners to run screws so I don't strip out the original holes. I can know them out later.
The isobaric set up won't be to add more bass but to reach lower to bring out the subharmonics that these speakers are missing. You don't realize how important it is to the overall impact of each song until it's no longer there and you're expecting to feel a certain vibration at some moment and it's not there. Without ever experiencing it, you'd never know it was gone, once it completes the song as it was intended to be, it just sets the mood. Of course it's only effective if it's really clean throughout the entire range. Only hearing bass as the recording has supplied it was another realization for me. The bass is only there when it's supposed to be.
In my car, I hear bass constantly but the old home system played the same songs completely differently with a much defined sense of reality and way deeper bass that only kicked in when it should. All bass tones are not just one note but formed several different sources at different levels of frequencies. It seems years of using a dedicated subwoofer has done to ruin music for so long.
Car is unavoidable, but I made sure to fix it with my last build and now it's gone and these speakers bring a much harder set of restrictions to work with to achieve it will take some time but I think it's doable with the correct plan.
My Moto phones have always had really good mics that are pretty close to reality when using that test app. I found the built in mic to be better than the Dayton calibrated test mic.
So I was able to run more tests and I eventually bypassed the internal crossovers and am back to active. Using a 3 way in 3 way mode. I tried the 2 way mode and even another 2 way crossover and the slope for the crossover makes for an obvious transition point.
The panels tested down to 260Hz usable output without anything crazy going on. I replaced the woofers, it appears 1 was replaced and the other has been reglued on the surround and they looked the same on the front, they were different years or something. I also removed half the fiber fill from the cab. Typically sealed cabs don't need to be packed full.
The bass has improved dramatically and the tests I have done need to be reran again just to see where I'm at. I have been swapping amps a bunch lately since I have 2 channels that get hot, I have removed those channels and tried several others in different configurations. I have 5 matching BGW A150s that can be bridged for 150w output , the 50w x2 Just isn't enough to do it and while I'm figuring out the bias settings I've subbed my old faithful Peavey CS400 with fan mod for the bass.
After tipping my the speakers down instead of upward, I have gained a huge improvement in sound quality and focus. Still not the same as the old flat panels.
I have moved them over 3 ft off the back wall and tied them so they cross in front of me while in an equal triangle set up. I'm crossed at 350Hz for the woofers the panels are running to natural roll off and I have been setting levels in the Crossover . Also finding if I need to reverse polarity on the panels or on the woofers or both!
The way the sound eminates from the panels needs to start with the rear side first (is what I would think to be logical) since it's traveling further via reflection, it should have a head start so it can meet with the front sound back in phase (somewhat).
Then theres the woofers phase, there's no way to predict if the crossover point is going to be in phase or not and using the overlap of sound could benefit front out of phase tones in the band where it would otherwise be gaining. Since the timber is different, the amount of cancellation is little but what is cancelled will help the 2 drivers transition without as much noticable change in sound.
It worked on my last set and I'm getting closer to a cohesive sound again. The mids are starting to be more directional and focused. There's a need to EQ them though there should be more mid detail in the 1kHz area. Sound like a hole there. When your speakers can reproduce that area without distortion, it becomes a huge part of realistic sounds. Increasing on other speakers just makes it sound awful and sqwauky. Where the panel will use that to bring things to life. Kinda like the opposite of what everyone used to set their 1970s eqs . The smiley face curve.
They're shaping up slowly. I've been thinking of moving the power supply into one of the side walls and using the back to mount a 2nd rear firing woofer in an isobaric config. There again comes the need to test with driver facing in or out and in phase with the front or not.
Cutting another back board to do do tests will make things easier too. I can cut 3 or 4 to have changes ready to go to mount and remove. Probably glue some blocks in the corners to run screws so I don't strip out the original holes. I can know them out later.
The isobaric set up won't be to add more bass but to reach lower to bring out the subharmonics that these speakers are missing. You don't realize how important it is to the overall impact of each song until it's no longer there and you're expecting to feel a certain vibration at some moment and it's not there. Without ever experiencing it, you'd never know it was gone, once it completes the song as it was intended to be, it just sets the mood. Of course it's only effective if it's really clean throughout the entire range. Only hearing bass as the recording has supplied it was another realization for me. The bass is only there when it's supposed to be.
In my car, I hear bass constantly but the old home system played the same songs completely differently with a much defined sense of reality and way deeper bass that only kicked in when it should. All bass tones are not just one note but formed several different sources at different levels of frequencies. It seems years of using a dedicated subwoofer has done to ruin music for so long.
Car is unavoidable, but I made sure to fix it with my last build and now it's gone and these speakers bring a much harder set of restrictions to work with to achieve it will take some time but I think it's doable with the correct plan.
I have gained a little bit more of the type of sound I'm looking for, the woofers adjustment made a considerable difference but it's still far from the bandwidth that I'm used to.
One more thing I found was to get them to produce a more perfect image was to bring them even further from the back wall. They were at 33" and now they're like 4 feet or more and 6 feet or more from side walls. I do believe that they would be better off with the back side covered and not even using the back waves. This would allow for them to be moved back to the wall which is much more practical for most users and it removes the positioning challenges and should help improve the bass as well. I do have a roll of thin insulation that's made for hot water tanks and it's sealed on both sides. I'm considering sticking a piece directly behind the entire length of the panel to see how much it changes the sound.
The curved panel does very little to increase the sweet spot in fact I'm thinking these have an even smaller area that can be considered to be the "spot". After moving them out into the room more, I finally did have a bit of the bubble of sound. It's far from the captivating experience that I once had but it's kind of there. The one thing I think curved panels do is improve the overall mixed sound when standing and not in front of them. But that's really not much use and makes little sense to bother with the design when it's taking away from their main goal of realistic headphone like quality sound.
One thing I have been wondering is if each segment of the panel is acting as it's own smaller panel within the overall length. There are cross supports that run horizontally and that's what holds the curvature in place, so since it's touching on those braces, does that make that area like its own smaller panel? The 2 upper spaces are smaller than the 3rd from the top and then they alternate sizes as they go down until the 8th and 9th segments, those 2 are both larger. Then they alternate till the last bottom 2 where they are small like the top 2.
This must have been planned for some reason. The thing I initially thought about the panel size was it was huge compared to the RTR JansZen panels and couldn't see why they were crossed at such a high point. I figured a panel as large as these should be able to hit 100Hz easily. But now that I see exactly how they're made it appears that they are acting as individual panels and not as one large panel. This becomes a problem since the tension of the mylar needs to be set evenly across the area. The amount of tension pulling on the top to bottom will be different in the middle than the top and bottom areas just due to the length of the mylar. The deflection will increase at the middle even though the divider braces hold it in place, there has to be a difference in the center on the vertical axis. From what I know the tension must be even across the entire area and the curving just seems to make this much harder to do than a flat and square surface. Maybe that's part of why JansZens design works so well for such a long time.
The curve also has to put more tension in the center of the brace since pulling it across the curved peak will always try to pull the curve flat at the highest point. There has to be some peaks as it vertically passes over the braces then in the center of the segment there has to be a different tension where the film will actually be curved inward due to the horizontal tension pulling it flatter across the center?
Maybe it's just me but I can't see how they can expect to produce the same correct sound that a flat panel can do quite easily and with very little thought into production.
I read Jazzmans rebuild of a curved panel and how he determines tension but I didn't see any reference as to where he specifically measured it. Since the segments on an Aerius are much smaller than the one he did you'd have to think that the tension in the center of the segment and the tension of the middle of the end segment would differ. I'll have to reread it again but I know that he explains the importance of tension being equal in all directions. Even drawing a square on the face to make sure it has stretched evenly. I wonder what it does when it's pulled across those arches? Peaks at the brace arch and a valley between the horizontal braces. You can't keep the curve and keep the exact tension when you're using a brace to curve it. It's impossible the side to side tension will be lost at the center of each segment and the shape of the film will have to change in order to maintain equal tension, there will be more film running across the arch brace than in the center of the segment if equal tension is kept. The film will be slightly flatter in the horizontal center ot it will have less tension than the tension across the brace. The differences in the length of film would be very small but it will be an imperfection that cannot be avoided.
Does this make sense? Maybe the loss in high frequency has more to do with the curve and film tension than dirt and loss of conductive material. How are the larger panels affected by age? It sounds like it's a ML problem and not a specific model that suffers from the loss. Maybe they could put some type of tuning tensioners at key positions like a guitar string. Then they could try to re-tension where it's needed later in life by just turning a screw or increase or decrease the arch height or width by fractions of millimeters using a set screw behind each arch brace?
One more thing I found was to get them to produce a more perfect image was to bring them even further from the back wall. They were at 33" and now they're like 4 feet or more and 6 feet or more from side walls. I do believe that they would be better off with the back side covered and not even using the back waves. This would allow for them to be moved back to the wall which is much more practical for most users and it removes the positioning challenges and should help improve the bass as well. I do have a roll of thin insulation that's made for hot water tanks and it's sealed on both sides. I'm considering sticking a piece directly behind the entire length of the panel to see how much it changes the sound.
The curved panel does very little to increase the sweet spot in fact I'm thinking these have an even smaller area that can be considered to be the "spot". After moving them out into the room more, I finally did have a bit of the bubble of sound. It's far from the captivating experience that I once had but it's kind of there. The one thing I think curved panels do is improve the overall mixed sound when standing and not in front of them. But that's really not much use and makes little sense to bother with the design when it's taking away from their main goal of realistic headphone like quality sound.
One thing I have been wondering is if each segment of the panel is acting as it's own smaller panel within the overall length. There are cross supports that run horizontally and that's what holds the curvature in place, so since it's touching on those braces, does that make that area like its own smaller panel? The 2 upper spaces are smaller than the 3rd from the top and then they alternate sizes as they go down until the 8th and 9th segments, those 2 are both larger. Then they alternate till the last bottom 2 where they are small like the top 2.
This must have been planned for some reason. The thing I initially thought about the panel size was it was huge compared to the RTR JansZen panels and couldn't see why they were crossed at such a high point. I figured a panel as large as these should be able to hit 100Hz easily. But now that I see exactly how they're made it appears that they are acting as individual panels and not as one large panel. This becomes a problem since the tension of the mylar needs to be set evenly across the area. The amount of tension pulling on the top to bottom will be different in the middle than the top and bottom areas just due to the length of the mylar. The deflection will increase at the middle even though the divider braces hold it in place, there has to be a difference in the center on the vertical axis. From what I know the tension must be even across the entire area and the curving just seems to make this much harder to do than a flat and square surface. Maybe that's part of why JansZens design works so well for such a long time.
The curve also has to put more tension in the center of the brace since pulling it across the curved peak will always try to pull the curve flat at the highest point. There has to be some peaks as it vertically passes over the braces then in the center of the segment there has to be a different tension where the film will actually be curved inward due to the horizontal tension pulling it flatter across the center?
Maybe it's just me but I can't see how they can expect to produce the same correct sound that a flat panel can do quite easily and with very little thought into production.
I read Jazzmans rebuild of a curved panel and how he determines tension but I didn't see any reference as to where he specifically measured it. Since the segments on an Aerius are much smaller than the one he did you'd have to think that the tension in the center of the segment and the tension of the middle of the end segment would differ. I'll have to reread it again but I know that he explains the importance of tension being equal in all directions. Even drawing a square on the face to make sure it has stretched evenly. I wonder what it does when it's pulled across those arches? Peaks at the brace arch and a valley between the horizontal braces. You can't keep the curve and keep the exact tension when you're using a brace to curve it. It's impossible the side to side tension will be lost at the center of each segment and the shape of the film will have to change in order to maintain equal tension, there will be more film running across the arch brace than in the center of the segment if equal tension is kept. The film will be slightly flatter in the horizontal center ot it will have less tension than the tension across the brace. The differences in the length of film would be very small but it will be an imperfection that cannot be avoided.
Does this make sense? Maybe the loss in high frequency has more to do with the curve and film tension than dirt and loss of conductive material. How are the larger panels affected by age? It sounds like it's a ML problem and not a specific model that suffers from the loss. Maybe they could put some type of tuning tensioners at key positions like a guitar string. Then they could try to re-tension where it's needed later in life by just turning a screw or increase or decrease the arch height or width by fractions of millimeters using a set screw behind each arch brace?
I am in the middle of adding a 2nd woofer to one of my Aerius right now, I removed the crossover since I'm all active. While I was moving the HT board I noticed there are 2 burnt resistors (#23 and #24) they're right after the 120v input. I didn't notice them when I bypassed the crossover but I also wasn't really looking that close at the other board. So I can't say it was like this when I got them. I tested them and still have resistance. The board is a bit burnt (they should have been mounted suspended off the board) but there's no trace damage.
Has anyone heard of this happening before? I thought it was really strange that those 2 would get so hot, I can't even think of what could have caused this. I'm going to cut the main body part of the resistors out and leave the leads connected to the board and wire new resistors on the leads and keep them away from the board. I don't even want to chance removing them from the board at the solder joints since the board is crusty and will end up with damage to that connection.
I'm right at the point of installing the second driver. I don't need the panels running to do the woofers tests, they were still working fine before I removed the back cover and I certainly would have smelled those big resistors burning at some point if it happened while I owned them.
I had a crossover burn up on me in an old Infinity ESL, when that happened I could smell it like crazy and it was just the cardboard roll former they used to make a coil. It was barely burnt, there's no smoke residue on the stuffing and I have a feeling that the previous owner (I have never cranked them up yet) did it and replaced the stuffing and sold them to me. He knew they had a problem but they did work. I'm going to check the other one right now a d see if it's ok.
I'll post pictures of the 2nd woofer once I figure out which way to mount and wire that will increase depth. As it is now, (I'll see if I can post a screenshot of my last sweep I did earlier today as my before) this is what it looks like. I'm running an old Peavey CS 400 on my woofers while I figure out setting bias on one of my QSC 3500 series 3 amps. Have had a random but very seldom idle heat issue with one channel. I leave them on 24/7 and a few times I've seen the red light on while idle. If I play music, the light goes out but the amp is always warm on that side.
Just last week I had a hot led flash on one side of my other amp so I swapped both good amps in one case and have the boards on my bench.
I know the one is a bias issue that requires a distortion meter and a noise generator along with a scope to set bias. I have a scope that I verified is still working but that's it. Also need load resistors and it's a complex 4 part test and set up that sets the crossover from low rail to high rail when switching from A to AB when setting the bias. I have other amps but needed to test the Peavey. It had a blown fuse and I parked it years ago, replaced the fuse and it works great?
I had acceptable bass with different woofers and the Peavey amp. The amp is barely working and only see the first LED lit during normal listening. After much repositioning of the speakers I was able to get a little bit of what I expected when I moved them over 4ft from the front wall and about 8ft apart with slight toe in. My JansZens were just 2.5ft from the front wall with a toe in that crossed in front of the seat position. I'm still not getting the full headphone effect but it's close. I still think the curve is interfering with the rear waves. The rear woofer may be able to reinforce it and bring it together but I'm worried about the distance from the wall being to far away to get it timed correctly. I've always had all woofers aimed in at me in previous designs.
I have a noise that enters at around 160Hz, cabinet vibration on the side I'm currently working on and I couldn't find it or stop it using my hands on the outside and I'm hoping that removing and remounting the boards on the side wall will fix it. The HT board will fit perfectly behind the brace and I replaced those tiny wire posts with true 10ga type screw down all metal ones and a 4 post cup type terminal. I'll be sealing everything with hot glue to try and make the isobaric idea working properly. There can't be any leaks or the isobaric loading will not be effective.
I'll report back in the afternoon tomorrow with more results.
Oh yeah here's today's sweep with no EQ.
This is last week after new woofers and EQ.1
Before new woofers
Here's one of a speaker I put together using some old drivers just to prove that paper cone drivers and mismatched parts can sound better than most bookshelf speakers made by Infinity using dome tweeters. This is an old Sonic cabinet with 10" Marantz woofers, a sealed back sonic (pioneer) 3in mid and a Bose 501 2.5in tweeter with a 3 way crossover that uses 3 caps, 2 resistors and 2 coils.
The median line disappears some times when I do screen shots but this isn't at all too bad for no tweaks or EQ. I have other sweeps with different mid and tweeter combinations. DLK and KLH as well as the sonics and a few other paper tweeters had similar results. This was the best sounding overall using a tiny AliExpress 50wx2 +100sub (not using the sub output) amp powered by a 24v 20A PSU.
Has anyone heard of this happening before? I thought it was really strange that those 2 would get so hot, I can't even think of what could have caused this. I'm going to cut the main body part of the resistors out and leave the leads connected to the board and wire new resistors on the leads and keep them away from the board. I don't even want to chance removing them from the board at the solder joints since the board is crusty and will end up with damage to that connection.
I'm right at the point of installing the second driver. I don't need the panels running to do the woofers tests, they were still working fine before I removed the back cover and I certainly would have smelled those big resistors burning at some point if it happened while I owned them.
I had a crossover burn up on me in an old Infinity ESL, when that happened I could smell it like crazy and it was just the cardboard roll former they used to make a coil. It was barely burnt, there's no smoke residue on the stuffing and I have a feeling that the previous owner (I have never cranked them up yet) did it and replaced the stuffing and sold them to me. He knew they had a problem but they did work. I'm going to check the other one right now a d see if it's ok.
I'll post pictures of the 2nd woofer once I figure out which way to mount and wire that will increase depth. As it is now, (I'll see if I can post a screenshot of my last sweep I did earlier today as my before) this is what it looks like. I'm running an old Peavey CS 400 on my woofers while I figure out setting bias on one of my QSC 3500 series 3 amps. Have had a random but very seldom idle heat issue with one channel. I leave them on 24/7 and a few times I've seen the red light on while idle. If I play music, the light goes out but the amp is always warm on that side.
Just last week I had a hot led flash on one side of my other amp so I swapped both good amps in one case and have the boards on my bench.
I know the one is a bias issue that requires a distortion meter and a noise generator along with a scope to set bias. I have a scope that I verified is still working but that's it. Also need load resistors and it's a complex 4 part test and set up that sets the crossover from low rail to high rail when switching from A to AB when setting the bias. I have other amps but needed to test the Peavey. It had a blown fuse and I parked it years ago, replaced the fuse and it works great?
I had acceptable bass with different woofers and the Peavey amp. The amp is barely working and only see the first LED lit during normal listening. After much repositioning of the speakers I was able to get a little bit of what I expected when I moved them over 4ft from the front wall and about 8ft apart with slight toe in. My JansZens were just 2.5ft from the front wall with a toe in that crossed in front of the seat position. I'm still not getting the full headphone effect but it's close. I still think the curve is interfering with the rear waves. The rear woofer may be able to reinforce it and bring it together but I'm worried about the distance from the wall being to far away to get it timed correctly. I've always had all woofers aimed in at me in previous designs.
I have a noise that enters at around 160Hz, cabinet vibration on the side I'm currently working on and I couldn't find it or stop it using my hands on the outside and I'm hoping that removing and remounting the boards on the side wall will fix it. The HT board will fit perfectly behind the brace and I replaced those tiny wire posts with true 10ga type screw down all metal ones and a 4 post cup type terminal. I'll be sealing everything with hot glue to try and make the isobaric idea working properly. There can't be any leaks or the isobaric loading will not be effective.
I'll report back in the afternoon tomorrow with more results.
Oh yeah here's today's sweep with no EQ.
This is last week after new woofers and EQ.1
Before new woofers
Here's one of a speaker I put together using some old drivers just to prove that paper cone drivers and mismatched parts can sound better than most bookshelf speakers made by Infinity using dome tweeters. This is an old Sonic cabinet with 10" Marantz woofers, a sealed back sonic (pioneer) 3in mid and a Bose 501 2.5in tweeter with a 3 way crossover that uses 3 caps, 2 resistors and 2 coils.
The median line disappears some times when I do screen shots but this isn't at all too bad for no tweaks or EQ. I have other sweeps with different mid and tweeter combinations. DLK and KLH as well as the sonics and a few other paper tweeters had similar results. This was the best sounding overall using a tiny AliExpress 50wx2 +100sub (not using the sub output) amp powered by a 24v 20A PSU.