Martin Logan Aerius i crossover upgrades

[zinda]

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.

 

[mattstat]

JansZen uses push pull and ML is just push.

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.

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.

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."

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.

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"

They don't have that perfect rear waves that normally will meet back up with the front wave but 1 cycle behind.

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 side is the first to produce sound?

Which one of these waves is the first to move?

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".

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

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.

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).