Here's what the finished addition looks like
The change is dramatic, the imaging has improved greatly but is still lacking, they sound more like a dome tweeters in that they have a bit of harshness, like a slight sybilence (not sure how it's spelled) I'm very hesitant to wash them since I keep reading how they are coming loose on the sides. Doesn't that completely destroy them when they loose tension? People act like that's not a big deal, but to me that would make them junk.
They seem to work as they should there's plenty of sound coming from them and they test good from 250 to 20kHz.
The change is dramatic, the imaging has improved greatly but is still lacking, they sound more like a dome tweeters in that they have a bit of harshness, like a slight sybilence (not sure how it's spelled) I'm very hesitant to wash them since I keep reading how they are coming loose on the sides. Doesn't that completely destroy them when they loose tension? People act like that's not a big deal, but to me that would make them junk.
They seem to work as they should there's plenty of sound coming from them and they test good from 250 to 20kHz.
Modern electrostatic speakers are push-pull (including Martin Logan). The fact that the diaphragm is between the front and back stators tells you this. Single-ended electrostatics have high levels of distortion at higher excursion.
What you are describing is most likely just the effect of extremely narrow vs wider dispersion. I think you may be assigning too much importance to the shape of the rear output. Narrow dispersion designs tend to sound more focused at the expense of soundstage depth and breadth. You get less room interaction with narrow dispersion speakers in general.
https://www.linkwitzlab.com/rooms.htm
"The off-axis radiation behavior of a speaker determines the degree to which speaker placement and room acoustics degrade the accuracy of the perceived sound."
https://www.linkwitzlab.com/listening_room.htm
"the loudspeakers must be placed at some minimum distance from those large surfaces in order to delay specular reflections by more than 6 ms. This allows the brain to give primary attention to the earlier arriving direct sound from the loudspeakers"
Since wavelength is different for each frequency, but distance to the wall is fixed, I'm not sure what you are getting at here.
https://www.linkwitzlab.com/rooms.htm
"Often concern is expressed over the fact that the rear radiation from a dipole is out of phase with the front radiation, and that thus any sound reflected from a wall behind the speaker would cancel sound coming from the front of the speaker. Cancellation can only occur when direct and reflected sounds are exactly of opposite phase (180 degrees) and of the same strength. Since direct and reflected sounds travel paths of different length, they undergo different amounts of phase shift. Thus, the phase and magnitude conditions for cancellation are given only at certain frequencies, if at all. At some other frequencies direct and reflected sounds will add. The same also applies to a monopole speaker in front of a wall. The only difference is in the frequencies for which addition and subtraction occur. The best remedy is to move the speaker away from the wall, or to make the wall as sound absorptive or diffusive as possible."
Which one of these waves is the first to move?
If you compare a flat panel of similar width whose entire area is playing midrange and up, you do see wider dispersion with the Martin Logan approach.
Innersound Kaya
https://www.stereophile.com/content/innersound-kaya-reference-loudspeaker-measurements
Martin-Logan SL3
https://www.stereophile.com/content/martinlogan-sl3-loudspeaker-measurements-part-2
Yes. In a completely open, essentially undamped panel the fundamental diaphragm resonance has very high Q and a large peak in output, which is difficult to use. Distributing the resonances across multiple frequencies makes them sound more natural. This was referenced at least as far back as Janszen's US Patent 2,631,196 (1953). Sound Lab also uses this approach and described it more thoroughly in US Patent 5,054,081 (1991), which didn't survive re-examination (1994).
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What I was asking about the segment, was each brace forms a segment, each segment has a specific size, do they act as a separate and individual output? There's 15 spaces total, I saw there's a small piece of clear plastic attached on the back of the panels in 3 spots, I don't know what they do. I'm still convinced that the curve is a detriment to their overall sound.
I've done quite a bit of testing using multiple JansZen panels in various configurations. I had a total of 28 panels to work with, 8 were the smaller 2.5" x 5" and 20 of the 5" x 5". When I placed them in a circular configuration with 4 panels horizontally and each panel placed about 8 degrees angled from each other evenly, my staging and imaging disappeared.
I basically copied the same layout that JansZen had with their 4 panel systems that were mounted with the backs blocked off but used them with the backs open.
I also tried copying the Infinity layout where 4 panels were on a horizontal plane with the outer panel angled outwards toward the side wall, that improved the focus a bit and have a bit more off axis sound but it didn't have the same sound as when all panels were aimed on the same plane.
I came to the conclusion that the curving would cause huge reflections or refraction as the waves crossed paths, blurring the rear waves. I haven't tried blocking the back side of the MLs yet but I intend to do test it this week. My guess is they will benefit from this in the stage and imaging, I will disconnect the rear woofer while testing. I should be able to move them back to the wall a bit as well.
It may surprise you that when I mounted the rear woofers, I tested them mounted in both directions, firing in the cabinet as shown and out and I tested with straight and reverse polarity. What I found was the best ended up as shown but I the wiring ended up connected in reverse, the positive connected to the negative on the driver?
My old Mirage subwoofer (BPS150i) uses 2 8" drivers both aimed outward and connected normally with both pos and neg connected to the drivers position and neg posts yet they called it an isobaric configuration. Technically that's not an isobaric configuration, but that sub has a fantastic sound. It's too bad that they didn't make it capable of turning the cutoff low enough to actually match other speakers properly.
I was surprised when I got both better bass, in frequency and in db there was an improvement, but, what I was really looking for was to help the imaging and stage that was eluding me with the MLs. That too was vastly improved, but I rechecked the tests to be certain what I found the first 4 times I tested and I saw duplicate results.
I ran 4 x 12's in my car in a clamshell isobaric configuration and had great results using cheaper drivers, I did that for 20 years and swapped out drivers a few times with the same results. The car subs were ported though, the ML woofers are sealed and I made sure the cabinets were sealed as well, filling any possible leaks with wood glue. They're about as good as sealed as can be possible with all drivers and the rear panels mounted with foam gasket. I made sure to use screws that do not penetrate the panel and sealed the front panel screw holes, then turned the new woofers to use fresh screw mounting that didn't penetrate the front baffel.
I summized that the back waves coming from the back side of the cone had helped to disperse the sound more like a dome driver would. Rather than firing in a more direct concentrated wave as it would when mounted normally. The pattern diffuses in all directions in a way that matches with the panels diffusion and solidifies the rear wave forming a more dynamic and coherent overall sound.
When standing up, the panels don't lose their highs and walking out of the room doesn't lose the sound as it did prior. My old JansZen panels had a major loss of sound once you left the bubble in the sweet spot, standing up was like flipping a switch. Since I'm not listening to them while I'm moving around, gaining off axis sound makes no difference to me, but at least I can say that they are much more enjoyable now than when I got them.
This may surprise you but I had no idea ML had other similar models that have rear mounted woofers until after I did this to mine. I found out after I went to post my plans and came across a few other models that incorporated the design. I know that they mounted the woofer aimed magnet inside the cabinet, I figured due to obvious reasons but I don't know how it's wired. I haven't heard any of those models yet so I can't say what the intension was for adding the 2nd woofer. From what I've read, the specs don't reflect much of a gain in lower frequency from models with 1 driver, so they may have been trying to reinforce the rear wave as I was. I'm wondering if there is any gain of the woofers is mounted as I did mine and of course a change in polarity might be needed.
I'm currently considering a pair of ESL X, is there anything I should know about that model? I know they make claims of a better designed panel but I've also read that the assembly is not nearly as stiff as they were in prior models. Some have complained the stator can easily move and would be better mounted with more isolation from the woofer cabinet.
I've also seen a few Sequals locally for a little bit less but they're quite a bit older (not as old the Aerius) than the ESL X and people are asking only a few hundred $ less which doesn't calculate properly on my eyes. $1200 for the ESL X and $1000 for the sequels with a center channel witch I won't need and not sure if it's desirable enough to sell.
I'm nearly done with my Heresy rebuild, cabinets are assembled and I'm nearly done painting 1 cabinet, need to finish polishing. Cabinets fit up is perfect, major upgrade in cabinet design over the original series 1. They sound great, nearly matching the MLs highs but a bit weaker bass output even with a slight increase in cabinet volume. Once again I tested with several 12" woofers and subs but found little to no gain in
I've done quite a bit of testing using multiple JansZen panels in various configurations. I had a total of 28 panels to work with, 8 were the smaller 2.5" x 5" and 20 of the 5" x 5". When I placed them in a circular configuration with 4 panels horizontally and each panel placed about 8 degrees angled from each other evenly, my staging and imaging disappeared.
I basically copied the same layout that JansZen had with their 4 panel systems that were mounted with the backs blocked off but used them with the backs open.
I also tried copying the Infinity layout where 4 panels were on a horizontal plane with the outer panel angled outwards toward the side wall, that improved the focus a bit and have a bit more off axis sound but it didn't have the same sound as when all panels were aimed on the same plane.
I came to the conclusion that the curving would cause huge reflections or refraction as the waves crossed paths, blurring the rear waves. I haven't tried blocking the back side of the MLs yet but I intend to do test it this week. My guess is they will benefit from this in the stage and imaging, I will disconnect the rear woofer while testing. I should be able to move them back to the wall a bit as well.
It may surprise you that when I mounted the rear woofers, I tested them mounted in both directions, firing in the cabinet as shown and out and I tested with straight and reverse polarity. What I found was the best ended up as shown but I the wiring ended up connected in reverse, the positive connected to the negative on the driver?
My old Mirage subwoofer (BPS150i) uses 2 8" drivers both aimed outward and connected normally with both pos and neg connected to the drivers position and neg posts yet they called it an isobaric configuration. Technically that's not an isobaric configuration, but that sub has a fantastic sound. It's too bad that they didn't make it capable of turning the cutoff low enough to actually match other speakers properly.
I was surprised when I got both better bass, in frequency and in db there was an improvement, but, what I was really looking for was to help the imaging and stage that was eluding me with the MLs. That too was vastly improved, but I rechecked the tests to be certain what I found the first 4 times I tested and I saw duplicate results.
I ran 4 x 12's in my car in a clamshell isobaric configuration and had great results using cheaper drivers, I did that for 20 years and swapped out drivers a few times with the same results. The car subs were ported though, the ML woofers are sealed and I made sure the cabinets were sealed as well, filling any possible leaks with wood glue. They're about as good as sealed as can be possible with all drivers and the rear panels mounted with foam gasket. I made sure to use screws that do not penetrate the panel and sealed the front panel screw holes, then turned the new woofers to use fresh screw mounting that didn't penetrate the front baffel.
I summized that the back waves coming from the back side of the cone had helped to disperse the sound more like a dome driver would. Rather than firing in a more direct concentrated wave as it would when mounted normally. The pattern diffuses in all directions in a way that matches with the panels diffusion and solidifies the rear wave forming a more dynamic and coherent overall sound.
When standing up, the panels don't lose their highs and walking out of the room doesn't lose the sound as it did prior. My old JansZen panels had a major loss of sound once you left the bubble in the sweet spot, standing up was like flipping a switch. Since I'm not listening to them while I'm moving around, gaining off axis sound makes no difference to me, but at least I can say that they are much more enjoyable now than when I got them.
This may surprise you but I had no idea ML had other similar models that have rear mounted woofers until after I did this to mine. I found out after I went to post my plans and came across a few other models that incorporated the design. I know that they mounted the woofer aimed magnet inside the cabinet, I figured due to obvious reasons but I don't know how it's wired. I haven't heard any of those models yet so I can't say what the intension was for adding the 2nd woofer. From what I've read, the specs don't reflect much of a gain in lower frequency from models with 1 driver, so they may have been trying to reinforce the rear wave as I was. I'm wondering if there is any gain of the woofers is mounted as I did mine and of course a change in polarity might be needed.
I'm currently considering a pair of ESL X, is there anything I should know about that model? I know they make claims of a better designed panel but I've also read that the assembly is not nearly as stiff as they were in prior models. Some have complained the stator can easily move and would be better mounted with more isolation from the woofer cabinet.
I've also seen a few Sequals locally for a little bit less but they're quite a bit older (not as old the Aerius) than the ESL X and people are asking only a few hundred $ less which doesn't calculate properly on my eyes. $1200 for the ESL X and $1000 for the sequels with a center channel witch I won't need and not sure if it's desirable enough to sell.
I'm nearly done with my Heresy rebuild, cabinets are assembled and I'm nearly done painting 1 cabinet, need to finish polishing. Cabinets fit up is perfect, major upgrade in cabinet design over the original series 1. They sound great, nearly matching the MLs highs but a bit weaker bass output even with a slight increase in cabinet volume. Once again I tested with several 12" woofers and subs but found little to no gain in
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Your terminology is a little confusing on this topic, but so is theirs, so that's understandable.
In Martin Logan speakers, each electrostatic panel is subdivided into multiple sections/segments. This is achieved through adding spacers made of 2-side tape within the overall panel (pink arrows pointing at them in image below). These fix the diaphragm at those points, so there's no diaphragm motion there. It's worth noting that typical Janszen panels are also divided in this way, but the sections are smaller and equally sized.
They're called "spars" in newer Martin Logan speakers, and they do increase stiffness, but their primary function is to divide the diaphragm into smaller sections, so proper stability is maintained and the fundamental diaphragm resonances of each section are where they want them. 100x the diaphragm-to-stator spacing is the typical limit used for diaphragm free span in electrostatics. Keeping free span below this limit prevents the diaphragm from collapsing into one stator when bias is applied. Less free span can be used though, especially if you are trying to shape the frequency response by using multiple diaphragm fundamental resonances - which is a natural result of using different sized diaphragm free areas. Longer skinny sections can be used as well; since the free span in one axis is small, you can exceed the 100x rule of thumb in the other direction.
So yes, the individual diaphragm areas are behaving as if they are separate. But they are close enough to their neighbors that they still behave as a single larger sound source in a general sense. This is similar to line sources using cone or dome drivers: yes, there are many drivers behaving individually, but they are close enough together that they behave like one larger speaker.
Though they use the flowery "innovative pressure compensation technology" description, my take on these elements in more normal terminology is that they're a form of damping to shape the diaphragm's frequency response (likely around fundamental resonance for that section). That's much cheaper, easier, and more reliable than trying to shape response around resonance electrically.
https://www.martinlogan.com/uploads/documents/manuals/manual_aerius.pdf
"The clear Lexan® panels on the back of the Aerius stator are the key elements of an innovative pressure compensation technology. Martin-Logan is able to tone-shape the diaphragm + or - 6dB without the use of an insertion loss crossover. The advantage of this system is a high efficiency driver with wide bandwidth capabilities of dimensions which are easily integrated into a domestic environment"
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