Acoustat Answer Man is here

[david yost]

The only times I have heard of frames cracking is when they have been tightly anchored or wedged to the ceiling and with rigid factory plinths, and I suspect that the frames fatigued because of upstairs foot falls causing the ceiling to flex downwards -- even if only several thousandths or hundredths of an inch. Over time, that is all it takes to break mdf or hdf. i don't think this would happen with hardwood or plywood frames. IOW, I don't think the movement of the diaphragms is responsible for the failures.

Best wishes,
David

[speedracer5]

Cracking wood frames? C'mon really guys? I'm slapping the membrane into the wires at that point the speakers are rendering distortion. Any hearing loss?

What about 4 room high baffles out of thick ply that are overall with of 15 - 16 inches with a 8" x 44" rectangle cutout for the 9" drivers? Add on some long reinforcement strips of 2" x 3/4" tacked to the back side of the baffle running the full length of each edge of each baffle. Put the bottom rectangle cut about 12 - 14 inches off the floor. The panels screw into the front side to reduce diffraction from the cut edge of the baffle hole. Ugly yes but figure a grill cloth assay. later for the covering the driver. To experiment with tilt back secure the test baffles with some propping sticks in the back. When you get all the rich angles cut some thin angled 45.5" strips that shim out the bottom of the driver to the best angle, that way the drive units are tilted and the baffle can remain plumb vertically.

[david yost]

Interesting ideas, speed, but if I can do the 1+1 layout no tilt will be needed.

Have you experimented with different baffle widths? What were your results?

Best,
David

[speedracer5]

David I have a very weird way of developing little unsubstantiated theories so bear with me here. I have an intuition from setting up the single panels several ways that they sound better with more imaging and bass by tilted back in toed in slightly. Listening with the panels parallel with the planes of the walls in the vertical there is something "wrong" with the soundstage and the weight of the bass is weaker. My theory is that using various slight tilt and toe in has more to do with pointing the back wave in a slight downward outward slope and I think the bass wave propagates toward the corners giving weight to the bass and the strong midrange is diffused and absorbed by carpet and other items behind (if thats the case) the speakers. Whatever does escape to the listener comes mostly around the outside edge rather than the center expanding the ambient "extras" added by that rear reflection which is going to take place no matter what. Also I contend that with any planar dipole that rear wave propagation as well as front, when parallel with the walls tends to cause an increase in "bouncing around" of the wave front for longer time and thus more reflections and destruction of good phase relationship with the room.

I can't prove any of this but even expensive ribbons like Apogee, other Stats like ML, the original Acoustat X, and countless others have a rearward tilt. I suppose since the 1+1 and 2+2 are floor to ceiling line source type arrangement that there really is not choice but I hooked up a pristine pair of 2+2 that I got a few months ago and it was lack luster compared to the single panels tilted slightly. Yeah more bass but the treble spaced out over 4 drive units just sounded to diffuse and weak. Lack of coherence in the sound stage. Now in a giant room with cathedral ceilings and plenty of power I have no doubt that the 2+2 might sound way better and more "right". I will have to avail myself of setting up a pair of 1+1 since I understand they have a tighter image. I think the 2+2 sounded tremendously tall. Which is what common sense would tell you. Well see.

If you can get a chance hook up one stereo pair of single 9" panels and put a base on them about 10" tall and some 3 or 4 inch cardboard wings. I used the stiff corner shipping caps that come in the packing on large appliances like fridge and stove.
If your so inclined, do this and tell me if there is anything special you hear happening with one panel per side despite the obvious compromises.
Oh sorry did not answer your question.
No really have not experimented with anything other than what I described cobbled together.
Have fun with it though it sure is neat to hear the magic when it happens.
Chris.

[tyu]

speed
M3s
I just can't stand the imaging anomalies that come with it. I'm not much help here but sharing what I've fiddled with might lead to some insight.

Sharing is all were doing...i say one panel is the best....but i can not live with one...

I Diyed a pr of 2+2s in the 90s.. an had to lean them back to get the sound right...An then put a Apogee ribbion for the mid-hi,s.... but can,t live with that...so if like you all are saying the 1+1s are the best....an thay are vary good... i cant live with them....i have ML,CLS,SL A1...an Acoustats...The ML with some mods do a better job than any Acoustats setup....what ever set up you have...1,2,4 8,...so for me the M3s give the best sound of Acoustat....as a ture full rang ESL...good luck have fun...happy hoho

[tyu]

I forgot...
The THD is so low with all ESL....That i wont more an more...ouT of them,i think most are the same...the only ESL that i can get Loud...is a 2way...like the Acoustat 1100..
So i just went to the ML an got the CSL, SL3s an the Ascent....an reworket the panels...an can get loud,Clear,sweet, big sound stage, out of the logans with a 60-80 watt tube amp.....but that me.

[AcoustatAnswerMan]

Originally Posted by hella356

I do know that the panels have sufficient force to crack the frames of a 2+2. Mine are cracked, and Moray James has noted that he's seen this several times. I think it could effect your results, but I guess there's only one way to find out. I'd just suggest you consider testing some form of bottom bracing.

If your frames are cracked, there can be only two possible reasons besides deliberate physical abuse of the speaker.

1. The wood has dried out, and internal stress has caused the wood to crack. This is more likely with the solid wood components of the frame, but I suppose it could happen to the MDF parts as well.

2. Much more likely, the speaker was not handled properly. I have seen this many times! NEVER pick-up and carry an Acoustat with the interface attached. The frame is not designed to withstand the twisting that the weight of the interface can exert. Always remove the interface, and preferably the base too, before picking up the speaker.

When doing the final positioning of the speaker, NEVER grab it by the frame to move it across the floor. This will place undue stress on the frame. Get down on your hands and knees and push the speaker by the base.

When I bought my Spectra 4400's (used) these simple rules had not been followed by the previous owner, and I had to repair the frames at several points.

[speedracer5]

Any further developments?

[MrAcoustat]

Originally Posted by speedracer5

Any further developments?

Here is one solution these will never crack but they weigh 200 pounds

[Reefin Dude]

Glad to see you are still around Andy. you helped me once before on my Monitor 4's disabling the auto turn off circuit. worked like a charm. unfortunately i now have an odd whistling sound coming from one of my servo amps. i have tried to get it fixed by two people local to me, but within 6 months the sound comes back. it is definitely in the amp and not in the panels. the last person i took the amp to replaced nearly all of the caps except the 1microfarad 3000VDC one, because they were not able to source it. i have replaced both of the monster transformers in the units many years ago. do you have any ideas on where to start to try and find remove the whistling, or to find a place that would fix the problem for more than 6 months? i guess i could hunt down a set of interfaces, but would rather keep the servo amps.

thanks,

G~