Electrostatic Speakers Vs. Horn/component Tweeter

Ok... So, crossover between panel and woofersx2 at 400Hz... I don’t think I would try and bi-amp with an AVR like that... You could be pushing 150 watts x 4 just for RMS... And when panels dive to 2 ohms your pulling 150 x 2 per channel (std) for the woofers and 150 x 3 (8, 4, 2 ohms with a doubling AVR/Amp) per channel... Ouch!!! No wonder you would have a thermal problem and clipping... Wonder what the total wattage output of that AVR can handle is... Spec is 150 watts per channel in _Stereo mode_ I read that as 2 channel... And I don’t see anything about multichannel mode... Also not sure how you would drive 2 left and 2 right stereo channels to bi-amp from an AVR like that... And how would driver time alignment work out... Speaker placement and time alinement is critical with these ESL hybrids... Hoping you have your room acoustics in order and use something like REW to get your speaker placement and room right...

The receiver is a 9 channel receiver with 9x150w 8ohn channels.  Designed to do a 9.1 or 9.2 setup.  Instead of doing front left and right and front high left and right, there is an option to bi amp the left and right which is what I’ve done.  Since the speaker nominal power is something like 320w RMS (I don’t recall exactly, been a while since I looked it up), it gives the power, and it says you can run it at 8ohm, but we all know that a speaker will suck down every bit of juice it can, and if a speaker can run down to 2ohm, it will try to suck that out of your receiver, whether the receiver can handle it or not.  I don’t have the clipping issue since I added the sub, however, there has definitely been a degradation of quality.  I believe it to be because of the limitation of setting the speakers to “small” and having the receiver apply it’s own filters/crossovers as it sees fit with no ability to manually adjust those.  That said, there isn’t much I can do to avoid clipping otherwise, unless I get a nice amp that will cost thousands I don’t have atm until I can get a reliable source of income.  You work with what you’ve got!  On the bright side, I don’t have a piece of crap Arcam receiver to ruin my day with constant failures ;)

ML suggests a power amplifier in the 20 to 400 watt range... I think they should do just fine with 150 watts... Although the ESL X are rated at 6 ohms which will cause your AVR to run up 190 watts per channel... Again more than enough to properly power your ESL Xs...

Back to you initial question about how your speakers may be damaged... The mylar may decompose with age, sun, dust... There is no voice coil like in a cone speaker which may deform or melt in an overpower situation...

I would be curious how the ESLs sound running as a vanilla 2 channel with out that extra subwoofer and set as large speakers in the AVR... You may be able to connect that subwoofer to other left and right channels or even tap directly to the standard left and rights... There is no reason to run them as anything less than full range speakers... You could then crossover your subwoofer in your subwoofer, given it has the capability to manage its own gain, crossover and phase or polarity...

My current setup is how ML recommended I configure it until I can get a dedicated amp.  Set to large mode, there is no need for a sub.  They sound incredible and have plenty of bass.  But when turned up, my receiver overheats on heavy bass songs and starts clipping.  Since this room is used more for movies than music, I need the sub to handle the various surround modes, but an also using it to reduce the workload on the receiver until I get a dedicated 2 channel for the speakers.  Then they will be set to large again :)

There is a wealth of information on ESL's at diyaudio.com under the Planars & Exotics forum.  The technical guru's there are extremely helpful and generous with their knowledge for both the novice and the more experienced enthusiasts.  They have helped me with mine on several issues I've had.  The Martin Logan owners forum should also have plenty of info.

Now I am not technical, but I will give you my understanding of what can go wrong with ESL speakers:

Because a normal amplifier does not produce enough volts to properly drive an ESL, a step up transformer is used for this purpose... anywhere from 50 to 150:1 ratio.  If over driven, they can fail causing low output and distortion...kind of a crackling noise.  This happened to me one night on my left speaker while listening  to some very loud and dynamic music.  However, this was pilot error on my part since I wired the transformer for maximum output vs a lower safer output(I'm still mad at myself for this!).  I don't think Martin Logan's have this problem?

A bias power supply charges the diaphragm to a high voltage(2000-4000 volts!) so it can interact with the stators-the curved perforated metal on your speakers.  If the power supply fails, there will be less sound or hardly any sound at all.

The thin mylar diaphragm vibrates by being attracted to the + or - stator, producing music.  Over time, the conductive coating may lose its effectiveness or actually separate from the diaphragm. Dirt, dust, and bugs can find their way between the diaphragm and the stators.  Bugs at nighttime can be quite entertaining with a light show as they are electrocuted...but this may cause a burnt hole in the diaphragm. The ML's should be well insulated to prevent this?

The stators are usually trouble free, unless they somehow lose their insulation or bent too close to the diaphragm.

These are items that may go wrong but most likely will not.  Hope this helps a bit.  Look into the forums for the real experts, though!

Bond-san