Electrostatic Speakers Vs. Horn/component Tweeter

I’m curious… when a horn or tweeter goes bad, it’s clearly obvious.  The driver is shot and the audio sounds clipped and distorted.  Electrostatic however, have massive surface areas and use static electricity to vibrate the material…. So when an electrostatic speaker goes bad, what actually happens to cause it to go bad, and does it go bad like a tweeter, where it goes from sounding fine to sounding like crap in a split second?  Or will an electrostatic speaker slowly decay over time, so you don’t notice it initially, and then one day, it just doesn’t sound as good as you remember it sounding?  If an electrostatic speaker goes bad, what causes it?  Is it torn material?  Is it something where you can replace a single small part?  Or do you typically have to replace the entire panel?

I’ve come across plenty of blown regular speakers in my life, but never a blown (if that’s even possible) electrostatic speaker.


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!



Do the speakers sound good in stereo set to full range? If so you’ve obviously got no issue and it’s all in the crossover. Also, when income allows don’t get an amp — get a stereo integrated amp.  Getting the Denon’s preamp outta the picture for stereo listening is at least as important as upgrading the amp if not more. The preamp section of your AVR sucks — they pretty much all do — and the preamp is crucial to get the best performance out of a system. Just my $0.02 FWIW.

This is always a good read when considering amplifiers for ESLs...


For stereo music a proper line stage preamplifier is always the best way forward...  And of course the proper paradigm amplifier for the type of speakers used...

Good luck in you choices...

All things suffer from entropy and degrade with time. E-statics are one of the more fragile designs in loudspeakers. The panels are plastic the electrical parts that energize the panels all break down a bit faster than in conventional dynamic designs they also attract dust another longevity killer they can arc causing burns in diaphragms and stators. If you want a timeless loudspeaker that can last generations look into horns. I have horn speakers from the 1940s that still meet the specs and work wonderfully. Or plan on repairs from time to time and enjoy your panels.

My receiver won’t utilize the subwoofer if the main speakers are set to stereo mode and large speakers. Setting them to small, tells the receiver to use the sub for low frequencies and thus reduces the draw from the speakers. My receiver is biamping the speakers at 150w per channel x2 per speaker, but it’s only 8ohm stable. It can do 6ohm above 1k frequency. I think these speakers can pull as low as 2ohm, so it’s just too much for the receiver to handle. This is why I need to eventually get a new amp when I can afford it.

@maverick3n1 The 1 Ohm impedance occurs at 20KHz where there is hardly any musical energy so your receiver will be fine. The speaker is higher impedance where there is more music energy, such as in the bass region.

When ESLs fail they have several symptoms. One is low volume which can be caused by a power supply failure. Buzzing and flapping is another due to tears in the diaphragm. Arcing (which might sound like a loud background hiss or actual sparking) is caused by too much power or excessive exposure to dust and moisture (possibly in the form of humidity); once that happens the panel can continue to arc, leading to failure of the membrane. They can degrade slowly or quite quickly depending on how they are treated. An underpowered receiver won’t be able to damage the speaker.