Has anyone tried double CLS

Sorry Lacee, I would never do that. The CLS (Curvilinear Line Source) is designed to provide a single, uniform, wavefront. Good dispersion, not generally a feature of flat electrostatic panels, is achieved using the (single line) curved driver. (Soundlab achieves a similar result using many smaller flat drivers in a curved array.)

Placing two (curved) lines side by side will create addition and subtraction nodes resulting from combining the two offset wavefronts, and will produce reinforcement and/or subtraction nodes all the way out in to the listening space. This cannot possibly reproduce an accurate soundstage hologram, rather just a "wall of sound".

Nor will adding more panels change (extend) the bass response lower than that of a single panel as Greg points out. If you are not getting adequate performance because the amp is having trouble driving an admittedly difficult load, then get a different amp, or perhaps try using an autoformer like the one made by Paul Speltz.

This subject has been covered ad nauseum for years. If you want confirmation of the points I've made, I suggest you speak with Jim Power or one of the other senior technical people at Martin Logan. It's a dead issue for me ;--)

As for stacking the old Quad 57s, that's an entirely different matter. The (individual) electrostatic drivers (1 bass in the middle 3 HF each side) run vertically top to bottom. So stacking 2 of the them still results in a uniform wavefront, twice as strong. A good thing too because 57s didn't play very loud without arcing and burning up! Again, this arrangement didn't increase their upper or lower frequency response specifications, and when Mark Levinson designed his "Super Quad" system, it consisted of subwoofer and super-tweeter units as well.
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The more panels, the more radiating area the more sound.Is this too hard to comprehend?The stacked Quads didn't magically have any different bass than they had before.They did not go lower.The bass just radiated into the room more so that you did not feel the need to augment it in any way.This is what I have found by doubling up on the CLS.My claim is that there is more bass, not deeper or different sounding bass.Just more bass power ,if that is easier to understand.The bass no longer feels like the poor country cousin.There is more bass loading the room.Would you have us believe that an Acoustat 2(2 panels per side) has the same bass energy as an Acoustat 4( 4 panels per side)?Yet this is your argument that an extra set of CLS will make no difference. The basic principal involved is air movement.More panels more air movement.More sound in the room is generated by 4 CLS as there is by 2.This is like saying that the panel sound from a pair of Aerius is no different than the sound generated from the Summit panels. It just isn't so in the real world, or in my listening. Larger panels, more sound.Four panels equates to more sound,and there are no problems.Addition and subtraction nodes?You should get some hands on experience and not postulate wild assumptions.What about the nodes created trying to pair up woofers and stat panels?Why do you think that most stacked or doubled up Quads systems don't have subs? I am sure there were a lot of people who said it was blasphemy and that it just wouldn't work as well.In any event,this set up works for me and it will for those who try it.

I think you don't know much about the Quad ESL.There is one treble panel in the centre of each ESL 57,flanked by a bass panel to either side. Three panels per speaker only.
So when you stack you get 2 treble panels and four bass panels per stack.You get more of the bass into the room this way and the result is you do not feel the need to add on subwoofers,neither do you need a super tweeter.When you add the subs and super tweeters you change the sound of the Quads and move into territory that is frought with problems,beaming tweeters, booming bass.Talk about room node problems. Doubling up on Quads or doubling up on CLS is not meant to change anything about the sound of either speaker, and I have never claimed it would.It is all about delivering more of the sound you liked about the speaker in the first place.

There is a difference between frequency response, dynamiccs loudness and volume. Frequency reponse will not be corrected by increasing loudness and or volume.

Many speakers bump up the bass to mask thier lack of low frequency extension. While your existing bass may get louder so does everytihng else. You get more volume but the same frequency curve.

Greg,

You hit it right! That is what I heard. The volume went up 5 fold on the CLS 1. There was no added extension in the bass or in the highs, not possible with this design. The point here is the CLS and any speaker for that matter can be "tweaked" to load a room so there is the "appearance" of more bass or dynamics using tweaks like anchor stands or direct drive amplification or just using a "fast" sub.

By the way in my old set up I used a subwoofer comprised of 2x10" paper cones and 1 passive 12" cone driver. Clever mechanical roll offs, which helped with the integration in that 100hz area.

Fun times with that speaker, the most transparent midrange but not the sweetest, that honor goes to the Stax 81's.