Minimal Output from ML Source panels

[DouginDallas]

Hey everyone, first post here.

I bought some used ML Source speakers on Sunday. They are in great condition. I hooked them up to a Marantz SR5015 AV receiver and the speakers sounded great Sunday evening and Monday evening. I turned on the system last night to listen to music and watch a couple shows and the sound was very foggy and there was minimal output from the electrostatic panels, however the subs were running fine. I tried unplugging the speakers and plugging them back in and that didn’t make a change. I checked all the connections and everything was connected properly and tightly. If I lean in close to the electrostatic panels, I can hear audio but it is very minimal.
I unplugged both speakers and left the unplugged all night and tried vacuuming them this morning but that also did not make a difference. Any ideas on how to remedy this?

 

[DouginDallas]

Let me add that I will try connecting the speakers to other channels on the receiver this evening and setting up through that to see if that makes a difference. I contacted the seller and he also suggested that and said that the receiver may not be powerful enough for the speakers. If that is the case, why did it work for two days? The Marantz supposedly is 100W per channel.

 

[Robert D]

The panels should still be good on those, since they werent launched until 2007. You can look on your speakers and there is a code that will show when they were made. The codes are listed somewhere on this board.

We have a lot of knowledgeable guys on here, hopefully someone will have an idea for you.

 

[Robert D]

https://www.martinloganowners.com/attachments/martin-logan-serial-number-decoder-pdf.20392/

 

[ttocs]

If you have a meter handy you can check the volts coming from the AC adapter(s). Recheck all the connections.

Vacuum the panels. Yes, vacuum the panels. I vacuum mine every other month, front and back.
Set the Source speakers as Large in the processor to isolate just the speakers themselves.
Try connecting to other outputs.

 

[DouginDallas]

I had already vacuumed the panels and that did not solve the problem, but I figured it out. Occam’s razor—I thought it seemed odd that both speakers would fail at the exact same time, so I began to wonder if it were my Marantz receiver. I swapped the outputs to different channels and tested and it seemed to work. So I did a hard reset on the Marantz and everything is operating at normal parameters and the speakers sound great.
So now to figure out why the Marantz receiver messed up....

 

[roberto]

Hola,
To me, the speakers are not getting the working bias voltage. Just make sure the power cords are fully inn into their socket. Power Conditioner suppling the working voltage to the AC cables too.

 

[Dgeez]

Can you borrow a friends amp rated at 100 watts RMS ? I'm not sure the Marantz has enough horse power.

 

[Russr]

"Sounds" to me like the Marantz was not happy working with the low impedance presented by the MLs.

Were you listening at increased volume prior to the "muffled" sound?

The Source is a lot newer than most of the MLs I have had/worked with, but assuming it's a passive design, and presents "the usual" low impedances associated with MLs, that would be my bet. Receiver protection circuit kicked it, and after cooling down/cycling power, it came back "OK".

If this IS the case, I would not suggest you adopt this as your "normal"... the receiver might be clipping, and you will damage your speakers.

If you like your receiver, maybe look at adding an external power amplifier - lots of info on here talking about which amps are well-rated for MLs.

Russ

 

[DouginDallas]

"Sounds" to me like the Marantz was not happy working with the low impedance presented by the MLs.

Were you listening at increased volume prior to the "muffled" sound?

The Source is a lot newer than most of the MLs I have had/worked with, but assuming it's a passive design, and presents "the usual" low impedances associated with MLs, that would be my bet. Receiver protection circuit kicked it, and after cooling down/cycling power, it came back "OK".

If this IS the case, I would not suggest you adopt this as your "normal"... the receiver might be clipping, and you will damage your speakers.

If you like your receiver, maybe look at adding an external power amplifier - lots of info on here talking about which amps are well-rated for MLs.

Russ

I will add an amp to my setup. But It wasn’t just cooling down/cycling power that made it come back “ok.” It had been off for 24 hours when I tried it and it wasn’t working properly. Then 24 hours after that I completely reset the microprocessor and everything works as it should.

 

[spkrdctr]

That is a simple microprocessor reset. It DOES NOT MEAN YOU NEED AN AMP. It happens all the time. They just mess up and a reset fixes them. Nothing wrong regarding power output of the unit. If the unit shut down while listening to it or cycled on and off then yes, that would mean the amp is going into protection mode. That most likely will not happen unless you turn it up quite a bit. So just use it as is and if it works for the next few months then you have no problem. If it starts needing a lot of resets then you do have a Marantz problem. Then it "could be" a power issue but right now you have to use it for awhile as "most likely" it is not a power problem. I look forward to hearing how this plays out. Good Luck!

 

[DouginDallas]

That is a simple microprocessor reset. It DOES NOT MEAN YOU NEED AN AMP. It happens all the time. They just mess up and a reset fixes them. Nothing wrong regarding power output of the unit. If the unit shut down while listening to it or cycled on and off then yes, that would mean the amp is going into protection mode. That most likely will not happen unless you turn it up quite a bit. So just use it as is and if it works for the next few months then you have no problem. If it starts needing a lot of resets then you do have a Marantz problem. Then it "could be" a power issue but right now you have to use it for awhile as "most likely" it is not a power problem. I look forward to hearing how this plays out. Good Luck!

I added an amp rather than going straight from the receiver and everything has sounded great until tonight, same problem. I tried resetting everything after powering everything down for twenty minutes and that did not fix the problem. I’ve left everything unplugged, will try vacuuming the speakers again in the morning and go from there.

 

[spkrdctr]

It sounds like you need your receiver repaired. Using your amp means it was not a power problem. So you may have a pre-amp problem in your Marantz. Once that is fixed you will be good to go. That little bit of troubleshooting helped you know what to fix. Good work! Maybe your Marantz finally broke for good which is a good thing. The repair guy will be able to fix a broken unit. Fixing an intermittent problem is near impossible. Let us know what they find and fix. I'm interested!

 

[wrat]

I added an amp rather than going straight from the receiver and everything has sounded great until tonight, same problem. I tried resetting everything after powering everything down for twenty minutes and that did not fix the problem. I’ve left everything unplugged, will try vacuuming the speakers again in the morning and go from there.

Do you have high humidity ? are your windows open? I have had similar issues that I am pretty sure are humidity related , I Had to remove speakers from usual room unplug , vacuum and leave them in a very dry room for 3 days, having both fail at same time is unlikely, now if humidity is high I just dont open the house

Unusual occurrences in the swamp | MartinLogan Owners (MLO)

 

[spkrdctr]

You should listen to the doctor!

 

[Phil in Ocala]

I live in Central Florida...humidity is always high..I have ML Clarity ESL + ESL ML center....no problem with humidity.

 

[ttocs]

I added an amp rather than going straight from the receiver and everything has sounded great until tonight, same problem. I tried resetting everything after powering everything down for twenty minutes and that did not fix the problem. I’ve left everything unplugged, will try vacuuming the speakers again in the morning and go from there.

I think we need more info in order to help you better.

When sound stops, is it one speaker, a pair of speakers at the same time, or all speakers at the same time?

If the no sound issue is ONLY with the Source speakers, and the problem follows whichever output the Sources are on and all other speakers work fine on the outputs that the Sources were previously connected to, then you need to check into Roberto's answer. Contact ML to ask for diagnosing assistance.