Small Hiss sound from EM ESLs

[dmimis1]

Hi,

I recently purchased a pair of (used but quite new) Electromotion ESls.

I have them about a week now and today i noticed something that i think I need some help with.

When I muted the source, and the whole room was completely quiet, I noticed a small hiss sound from both speakers (that I would describe as electrical)

Is the normal for esls which are using power for the panels, or is something wrong with my speakers.? The sound is definatly from the speakers, cause I shut down the power amp, and the hiss continued until the speakers stoped powering themselves after a couple o minutes.

Please help... these are my 1st of what I feel will be many MLs

Thanks in advance.

 

[roberto]

Hola and welcome,

The electrostatic speakers are very sensitive. If you turn off the amplifier, does this hissing noise is still present? Your electromotions, once they are activated with the music, can play a complete song, after you had taken off their power supply. If you turn off the amplifier-receiver, what ever you are using to drive them, if a noise is present, usually the culprit is the amp. If you have funny noises, this is a debris on the stat panels, and you can vacuum them with no problem, the whole panel, from top to bottom and from left to right. You must do this at the front of the stat panels. The front side is where the bias voltage is applied to the diaphragm.

If the hissing sound is coming from your amp, it is harmless and will not affect or could damage your speakers.

If I missunderstood something, please explain us again. We love to help! Do not panic...that's a normal thing. If you do not have the operation manual, here is what Martin Logan says about funny noises:

A problem has recently developed with my MartinLogan speakers. The right speaker seems to be hissing even when the amplifier and such are not connected. I was wondering if this sounds like any problem you have encoun- tered previously and have a simple solution for or might it be something which will need to be looked into more carefully.
Your speakers are dusty. See the vacuuming FAQ. The electrostatic charge on the element has attracted airborne dust or pollen. Since 1993, all of our speakers have been built with a charging circuit board that only charges the electrostatic element when music plays. At other times they are not charged and cannot collect dust. You can get the same benefit by simply unplugging them whenever they are not in use. A power strip is an easy way to do that.

You can download the users manual from here: https://www.martinlogan.com/uploads/documents/manuals/manual-electromotion-esl.pdf

Happy listening!

 

[dmimis1]

Roberto Hi,

Thanks for the quick reply.

A bit more confused now, but maybe my fault so let me clarify again. The hissing is there only when the speakers are powered (by their own supply). If the music is muted or even if the power amp is shut off completely the hissing continues until the speakers power goes off (in about two minutes) or I unplug their own power supply.

To make it completely clear: they hiss when powered even with no amp or connected!! I'll try vacuuming and hope that helps.

Thanks again

 

[roberto]

Hola dmimis1,

The panels are like a big capacitor and to charge them takes less than 2 seconds. But they remain charged for several minutes. Turn off your amp. The hiss could come from the output stage of the amp. I am trying to track from where the hiss is coming. No matter is you mute the music. The panels remain actives, and if you have noise from the output stage, this noise will be reproduced. Please, turn off the amp and report.

Reading you again, many amps while being turned off, their power supply remains supplying voltage from the power supply capacitors... Just watch at the back of the speakers a blue LED. Even having the power supplies plugged to the Main AC, their charge remains. Do not disconnect the power supplies of the speakers. Just turn off your amp and look if the blue led are led on. When the led goes off, then the stat panels working voltage has being not supplied, but they remain charged. I do believe that your problem is a signal to noise ration from your amp. Bring also the volume knob to the minimum. If the hiss had gone, them it is coming from the preamp section. The funny noises from the debris at the panels are really annoying. And it is a high pitch noise. Usually the debris can be located. What makes me to believe that the speakers are not the culprit, is because both are showing the same problem. If you have a faulty on the speakers, usually is one, not both at the same time...but it could happen too. I am just giving you the possibilities.

Happy listening!

 

[Ishaansuri]

Roberto Hi,

Thanks for the quick reply.

A bit more confused now, but maybe my fault so let me clarify again. The hissing is there only when the speakers are powered (by their own supply). If the music is muted or even if the power amp is shut off completely the hissing continues until the speakers power goes off (in about two minutes) or I unplug their own power supply.

To make it completely clear: they hiss when powered even with no amp or connected!! I'll try vacuuming and hope that helps.

Thanks again

Hi i am having the similar issue with fairly new ESL 9s. Did you manage to get to the solution of this one ?

 

[Robert D]

You guys are scaring me. My Prodigy speakers never did that. I figured the newer speakers would be improved even more. This does not sound good.

 

[msimanyi]

I'm guessing it's not "normal." I will have to put my ear right next to my panels on my new speakers, but I'm pretty sure they're silent and my old Aerius were dead quiet.

Edit: confirmed - dead quiet. So properly functioning "newer" speakers should be silent.

 

[Ishaansuri]

You guys are scaring me. My Prodigy speakers never did that. I figured the newer speakers would be improved even more. This does not sound good.

As heard from ML ..see attached screenshot

 

[msimanyi]

Perhaps some other "9" owners can give their speakers an up-close listen and share their results.

My 15As don't produce any kind of hiss, and I made sure they were on, powered up from playing, then paused everything to listen for it.

 

[Ishaansuri]

Perhaps some other "9" owners can give their speakers an up-close listen and share their results.

My 15As don't produce any kind of hiss, and I made sure they were on, powered up from playing, then paused everything to listen for it.

So this is like a static sound hiss. Like a squeal bzzz but not like white noise or like a record player ground sound. It's not being produced by the diaphram itself but i think the connection points or at joints on the panels. You touch the spot and it changes goes away comes back.

When your 15s are on and blue lights on. Keeping all on mute run your ear close and along the entire panel surface. Edges at the frame and like close to the stator. Front and back. Seebif there is a static sound. Doubt would be. Mine didn't have either for the last 18 months of active ownership.

I got these July 2021. New panels bias boards replaced Jan 2022 under warranty as they had some defect. Different thread on this.

Both speakers exhibit this consistently last 3 weeks or so. Monitoring it now daily to make notes when it's less more or different correlating to dust weather etc. Happens amps cables disengaged. They just need their power to begin showing this static hiss.

I swear my speakers are so clean they look like silver diamond mirrors sparkling. I like my things very clean so they can't be dusty to do this.

Absolute sound quality is not effected as of now. It's still fab.

Let's hope there are more ESL 9 owners around here to check. We seem to be a curious bunch