Thanks, that was very helpful, even if it cannot explain what I heard. I'll have to ask the seller to run a few tests by ear before I go on another 2x 200 km drive.
So if those panels are radiating full range over their full area, I understand how you would get horizontal beaming and a tight sweet spot. Vertically, if in a room that is not much higher than they are, they should form an inifinite line source (the very opposite of what I experienced). Since I have never listetened to a full range line source extending floor to ceiling: is that something that takes getting used to?
So if those panels are radiating full range over their full area, I understand how you would get horizontal beaming and a tight sweet spot. Vertically, if in a room that is not much higher than they are, they should form an inifinite line source (the very opposite of what I experienced). Since I have never listetened to a full range line source extending floor to ceiling: is that something that takes getting used to?
Still trying to understand what I heard earlier this week. How long does it take for the panels to charge? Would a degraded panel take signficantly longer to charge and then still play more softly?
But there is no way an incompletely charged or degraded panel sould have a skewed frequency response, i.e. close to no treble, is there?
But there is no way an incompletely charged or degraded panel sould have a skewed frequency response, i.e. close to no treble, is there?
In my limited experience, they seem to mostly charge within a couple minutes, but may get better over a day or two.
They can be damaged, the grids get brittle, they can get dust or other stuff between the wires and the diaphragm, but they don't otherwise degrade. 35 (40?) year old Acoustats, with C-mod and cleaning and any needed maintenance, can sound better than new.
If you want the Troubleshooting Guide search this thread.
Brandon
They can be damaged, the grids get brittle, they can get dust or other stuff between the wires and the diaphragm, but they don't otherwise degrade. 35 (40?) year old Acoustats, with C-mod and cleaning and any needed maintenance, can sound better than new.
If you want the Troubleshooting Guide search this thread.
Brandon
A panel with a defect in the bias circuit can take longer to fully charge, and it may never reach full charge. This is often caused by foreign material caught in the gap (causing stray leakage of the charge on the diaphragm). This is usually easy to remedy. A bad connection between the bias wire and the conductive coating can also cause charging issues, but that is less common and not easily repairable. However, I have never experienced a situation where a lack of charge caused poor treble response - it should just play at a lower level, equally at all frequencies. I won't say it CAN'T happen, only that I've never experienced that, nor can I fathom any form of fault whereby that would occur.
And since you observed this anomaly only in the upper of the two panels, we can rule out any defect in the driving electronics. If you heard the issue in both panels of one speaker, there are several things in the electronics that could cause this (some are an easy fix, others not so much).
There's also always the chance that someone, during the speaker's long life, that may done something to the panel that has affected its performance. I've seen some pretty crazy modifications done over the years, well meaning, but just plain wrong. If you're still contemplating purchase of these speakers, another listen is definitely warranted to make sure that what you heard is not just a weird effect of room acoustics. If you are convinced that is something wrong with the speakers, perhaps you should move on. Unless of course, the price is right and you like to tinker.
Thanks. At least for Martin Logan panels, one user seems to have experienced reduced trebles with degraded foils, and ER audio seems to say that a highly conductive coating is better for treble reproduction.
https://www.diyaudio.com/community/...ogan-and-audiostatic-esls.411321/post-7652097
I don't yet understand why this would be.
https://www.diyaudio.com/community/...ogan-and-audiostatic-esls.411321/post-7652097
I don't yet understand why this would be.
Be careful of the comparisons you make, between different brands, and even different models. Some speakers use a segmented approach (of various means), where not all panel is driven full range. Acoustat's later Spectra models use segmented panels, but the 1+1 should produce all frequencies equally from all panel surface area.
The ideal conductive coating should be extremely high in resistance, so that charge migration/localization does not occur during large excursions. Acoustat's panels took a huge leap in performance when the resistivity of the coating was increased from its previous (and already very high) resistance.
The ideal conductive coating should be extremely high in resistance, so that charge migration/localization does not occur during large excursions. Acoustat's panels took a huge leap in performance when the resistivity of the coating was increased from its previous (and already very high) resistance.
This may be true for Constant Voltage (low resistance - high conductivity) ESLs like Beveridge, but most ESLs like Acoustats, ML and Soundlabs are Constant Charge (high resistivity - low conductivity) ESLs.
The Constant Charge ESLs are said to have lower distortion, and much safer.
I think I have that right...
Constant Voltage diaphragms, like ones in Beveridge ESLs, are made of Aluminized Mylar - that NASA "Space Blanket" stuff. I re-mylared some ML CLS once with this stuff....then tore it all out and replaced with 6 micron regular mylar with Licron Crystal as coating....cannot remember if it sounded any better...
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I did if only briefly because after initially finding that I had to sit do get anything like a normal sound, I was operating under the false idea of a height limited tweeter segment.
I have two questions re stator wires:
Sometimes Acoustat hobbyists connect wires across the ends of the stator wires, to enable better electrical flow.
And claim it sounds better.
1. How the heck do you get insulation off the wire end loops with damaging the copper strands??
2. Do you know of wire available that works for well this purpose available in minimal quantities at an easy price?
Brandon
Sometimes Acoustat hobbyists connect wires across the ends of the stator wires, to enable better electrical flow.
And claim it sounds better.
1. How the heck do you get insulation off the wire end loops with damaging the copper strands??
2. Do you know of wire available that works for well this purpose available in minimal quantities at an easy price?
Brandon
I would not bother with this mod - like AAM indicated - it works or it doesn't. If the panel works, the electrons are flowing. Connecting the stators in parallel instead of series should not provide any benefit.
You very well could trip it all up and wind up with a dead panel. If you do this mods and bugger it up, I can sell you a few good 3 wire panels
I agree, this is a bad idea. You will likely damage the panel in the process. Even if successful, the chances of any audible sonic improvement is very low. and not worth the effort. People come up with all sorts of ideas for modifying the speaker. Ideas for modifying the panel are the worst. Most of them yield no improvement if they don't ruin the speaker in the process. Sit back and enjoy.
The answer to your second question lies within my answer to your first question.
The answer to your second question lies within my answer to your first question.
Hi everybody, hi Andy,
I'm new to this forum but as an Acoustat lover for the past 43 years I thought that it was time to chime in.
Recently I've been tinkering with replacements for the 47uF electrolytic cap in the 121-C interfaces. I have read posts in this forum that
endorse the use of polypropylene caps and I know that they are a big step up. But aside from suggestions listing Dayton and Solen Caps
I have not come across a discussion of other brands that may offer even higher sound quality. In my recent experiments I have tried Solen Fast Caps,
Jantzen Standard caps, Mundorf EVO Aluminum.Oil, and Claritycap CSA's. The biggest revelation so far has been that the choice of a 47uF cap has a great influence on bass as far down as 100Hz, if not below that. What we call the High Frequency transformer appears to cover almost the entire frequency spectrum! I have found that each PP cap seems to have it's strong points: The Solens are a bit rough but have fantastic contrast and are very exciting. The Mundorfs are hyper-detailed but lack bass. The Standard Z's are boring but well balanced, lacking dynamics and the Claritycap CSA's are
smooth, coherent and have good dynamics but may have a slight lack of spaciousness (jury still out on that.) So the best all-around cap at this
point is the Claritycap CSA. But I've swapped caps so often in the last few months that I lost my way and had to find the trail again. To do that I reinstalled the electrolytics. This was informative because they sounded pretty good! The bass was just right and other qualities were well balanced. This, after all is how Jim Strickland auditioned these speakers. My feeling now is that there are PP caps that are not as good in Acoustats as well bypassed electrolytics but that the right PP can be spectacular and deliver results beyond any bi-polar electrolytic. However I have yet to find one that does everything at the highest level. Next, the Mundorfs will go back in but with an added 1.5 uF cap to increase bass. Maybe that will be the keeper. So, can some of you let me know what your preferences are in this regard? It would be great to know which caps you like in your Acoustats. I apologize if this has already been covered but with 166 pages, I might have missed something. Thanks!
JGBart
System:
Acoustat 1+1+1's (1+1's with an added panel on the side) or are they 2+2-1 ?
VTL ST150 amp (also Mac MC60's)
ARC SP8 preamp
Mogami 3082 coax speaker cable (as per Roger Sander's suggestion, amazing)
Janis W1 sub
Linn LP12
Line Magnetic LM502CA DAC
I'm new to this forum but as an Acoustat lover for the past 43 years I thought that it was time to chime in.
Recently I've been tinkering with replacements for the 47uF electrolytic cap in the 121-C interfaces. I have read posts in this forum that
endorse the use of polypropylene caps and I know that they are a big step up. But aside from suggestions listing Dayton and Solen Caps
I have not come across a discussion of other brands that may offer even higher sound quality. In my recent experiments I have tried Solen Fast Caps,
Jantzen Standard caps, Mundorf EVO Aluminum.Oil, and Claritycap CSA's. The biggest revelation so far has been that the choice of a 47uF cap has a great influence on bass as far down as 100Hz, if not below that. What we call the High Frequency transformer appears to cover almost the entire frequency spectrum! I have found that each PP cap seems to have it's strong points: The Solens are a bit rough but have fantastic contrast and are very exciting. The Mundorfs are hyper-detailed but lack bass. The Standard Z's are boring but well balanced, lacking dynamics and the Claritycap CSA's are
smooth, coherent and have good dynamics but may have a slight lack of spaciousness (jury still out on that.) So the best all-around cap at this
point is the Claritycap CSA. But I've swapped caps so often in the last few months that I lost my way and had to find the trail again. To do that I reinstalled the electrolytics. This was informative because they sounded pretty good! The bass was just right and other qualities were well balanced. This, after all is how Jim Strickland auditioned these speakers. My feeling now is that there are PP caps that are not as good in Acoustats as well bypassed electrolytics but that the right PP can be spectacular and deliver results beyond any bi-polar electrolytic. However I have yet to find one that does everything at the highest level. Next, the Mundorfs will go back in but with an added 1.5 uF cap to increase bass. Maybe that will be the keeper. So, can some of you let me know what your preferences are in this regard? It would be great to know which caps you like in your Acoustats. I apologize if this has already been covered but with 166 pages, I might have missed something. Thanks!
JGBart
System:
Acoustat 1+1+1's (1+1's with an added panel on the side) or are they 2+2-1 ?
VTL ST150 amp (also Mac MC60's)
ARC SP8 preamp
Mogami 3082 coax speaker cable (as per Roger Sander's suggestion, amazing)
Janis W1 sub
Linn LP12
Line Magnetic LM502CA DAC
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