A little big Help

[user 49888]

Good morning everyone
I bought a pair of ML Impression ESL 11As about 8 months ago after listening to some other speakers along with a dear friend, and we were very enthusiastic listening to them at the point that I bought them. At the time of choice I had no doubts about my EAM LAB Element 701 mono amplifiers capable of Power rms 650/1000/1800 - 8/4/2 ohm and so I enjoyed good music at medium low level until a few days ago.
Taking advantage that some neighbor is on vacation I finally turned up the volume and ... I had a big disappointment !! The full and full-bodied sound became thinner: bass and mid-bass that tend to disappear as the volume increases with a very disappointing sensation.
I do not hide that I am on the ground as I hoped to have found a definitive solution and I ask for advice in this Forum as I do not know which path to take.
Thanks in advance to everyone who has a suggestion for me and sorry for my English.
Best
Paolo

 

[Don Quichotte]

Hi! Your amplifiers are real beasts it seems, so I cannot imagine them as being the culprit. I also own the Impression 11A and I haven't heard the thinning you are describing, but then my "loud" is not very loud so I don't know how they behave at 90+ dB. My feeling though is that they are not really suitable for very loud listening, for that you would need the larger 10' drivers of the Expression 13A.

On the other hand, I don't know how much experience have you had with electrostats before. The room treatment and speaker placement are HUGELY important in my experience, to the point that if I had to remove a couple of pillows I'm using as improvised absorption treatment I would simply sell the speakers the next day. I learned this the hard way, by trial and (a lot of) error. Too little absorption and the sound becomes very thin, dry, remote, synthetic and very boring; too much and you get a congested soup without texture - and, interestingly, the treble extension suffers in both cases. So, by all means, do experiment with some absorption behind the speakers (try less and more, move it around inch by inch etc., don't just throw something absorbing there and call it done), it might restore a lot of body and bass.

 

[ttocs]

The woofers in the 11A are powered by internal amps, so I don't understand why the bass would disappear unless when at full volume there is not enough electrical power for the amps to produce their full power.

If it were me, I'd check all the electrical outlets.

How many electrical circuits are your audio components plugged into?

 

[user 49888]

Hi! Your amplifiers are real beasts it seems, so I cannot imagine them as being the culprit. I also own the Impression 11A and I haven't heard the thinning you are describing, but then my "loud" is not very loud so I don't know how they behave at 90+ dB. My feeling though is that they are not really suitable for very loud listening, for that you would need the larger 10' drivers of the Expression 13A.

On the other hand, I don't know how much experience have you had with electrostats before. The room treatment and speaker placement are HUGELY important in my experience, to the point that if I had to remove a couple of pillows I'm using as improvised absorption treatment I would simply sell the speakers the next day. I learned this the hard way, by trial and (a lot of) error. Too little absorption and the sound becomes very thin, dry, remote, synthetic and very boring; too much and you get a congested soup without texture - and, interestingly, the treble extension suffers in both cases. So, by all means, do experiment with some absorption behind the speakers (try less and more, move it around inch by inch etc., don't just throw something absorbing there and call it done), it might restore a lot of body and bass.

Hi Don and 1000 thanks for your answer .. in fact the problem starts after 75db and sometimes I would like to go a little further.
I have not had any experience with electrostatic transducers before but what I can say is that my dear friend with whom I have listened to the ML and has the same EAM LABs in the end bought a pair of Perlisten S7t with extraordinary results !!
I thank you again for all the suggestions and I confirm that in recent months I have made all the possible movements once positioned approximately in the best listening point (a little ahead, a little back, a little to the right and a little left) by putting something absorbent behind them and something reflective behind them.
The problem in my opinion remains this cut of the low / medium-low frequencies as the volume increases.
A test to do is to look for (here in Rome) a dealer for a home test with another amp to verify the interface with ML or to think of replacing them with others.
Regards
Paolo

 

[user 49888]

The woofers in the 11A are powered by internal amps, so I don't understand why the bass would disappear unless when at full volume there is not enough electrical power for the amps to produce their full power.

If it were me, I'd check all the electrical outlets.

How many electrical circuits are your audio components plugged into?

Hi ttoc and thanks to you too for your observation ... actually on the wall behind speakers, amplifiers etc (at a distance of about 90 / 100cm) there are a series of wall sockets with which I feed the two MLs, the two EAM LAB power amplifiers and a PS Audio Stellar Power Plant 3 feeding a CA X50D a Sw1x DAC and a phono pre.
Pensi che ci possa essere un problema qui?
Regards

 

[ttocs]

Here's the thing. If the wires attached to the electric receptacle are loose, whatever is plugged in will not get full power. Also, it can be dangerous if those wires are loose. If you know a electrician, or know someone with knowledge about electrical, this would be best to have someone check the wiring.

One test you can easily do is to disconnect as much as you can, but leave connected the preamp, one amp, and one speaker. If the same problem happens with bass disappearing, then it's got to be something with the electric.

 

[Brandon Hartwick]

Most likely placement related

 

[msimanyi]

I agree with Brandon.

But... the person who responded juuuust before him - ttocs - is, in my opinion, one of the best resources for *that* specific problem, as he has lots of experience with complex audio hardware, placement and room correction. Given his simpler suggestion to check the electrical connections, I'd start with that.

Is the PS Audio regenerator showing any faults or power problems? Even if the amps and speakers aren't plugged into it, that might reinforce ttocs' idea.

Important question: Have you acquired the PBK (Perfect Bass Kit) and run ARC on the 11As? If not, that would be my next step. The difference in my room (admittedly, on my BalancedForce subwoofers) was astounding.

If neither of those help you, you'll probably be best served acquiring a decent microphone and downloading REW so you can measure what's happening and post the graphs for feedback. Alternatively, posting a room layout sketch or some photos might help too, if you're looking for possible placement suggestions.

Edit: I almost hesitate to ask this because it seems so unlikely. Is there any kind of loudness function being applied by your pre-amp / processor?

 

[ttocs]

Important question: Have you acquired the PBK (Perfect Bass Kit) and run ARC on the 11As? If not, that would be my next step. The difference is my room (admittedly, on my BalancedForce subwoofers) was astounding.

If neither of those help you, you'll probably be best served acquiring a decent microphone and downloading REW so you can measure what's happening and post the graphs for feedback.

Yes to both of these suggestions.

With REW involved it is much easier to "see" what's going on with the sound.

You don't need a good mic for a quick test, you can just use the built-in mic on a laptop. It's the "difference" of low volume vs high volume you'll want to look at, and not the overall level which of course will be different, but the relationship of bass vs treble. If it looks like the bass is lower in output than treble when using loud volume but the bass is the same level as treble at low volume, then you know what you're hearing is accurate. This just confirms the problem. Next you need to find out why it's happening.

 

[MisterB]

Very interesting issue. I don't know how much I can help, but I'm interested to see how this progresses. It does seem like some kind of power issue with the 11A's bass modules. It doesn't seem like a bass null issue. I've never known nulls to just appear at louder volumes. They're usually there all the time.

Crazy theory here (and maybe a dumb one that shows my lack of knowledge...) but could the OP's amps be putting out too much current and/or wattage into the Impressions, causing the built-in bass amps to shut down at higher volumes? The 11's are rated for 20-550 watts. The EAM's are putting out 650/1000/1800 watts rms at 8/4/2 ohms. I would think the ML bass module amps would have some sort of built-in protection. Maybe that's kicking in?

 

[ttocs]

Very interesting issue. I don't know how much I can help, but I'm interested to see how this progresses. It does seem like some kind of power issue with the 11A's bass modules. It doesn't seem like a bass null issue. I've never known nulls to just appear at louder volumes. They're usually there all the time.

Crazy theory here (and maybe a dumb one that shows my lack of knowledge...) but could the OP's amps be putting out too much current and/or wattage into the Impressions, causing the built-in bass amps to shut down at higher volumes? The 11's are rated for 20-550 watts. The EAM's are putting out 650/1000/1800 watts rms at 8/4/2 ohms. I would think the ML bass module amps would have some sort of built-in protection. Maybe that's kicking in?

hmmmmmm, this is interesting.
I don't know the answer either, but I think this is a valid theory, overloading the speaker input with too much power.

 

[Ronin]

If you have not already, try taking the PSA Re-Gen out of the system completely (or at least for speakers and amp) ,then try your volume test.

 

[Robert D]

Very interesting issue. I don't know how much I can help, but I'm interested to see how this progresses. It does seem like some kind of power issue with the 11A's bass modules. It doesn't seem like a bass null issue. I've never known nulls to just appear at louder volumes. They're usually there all the time.

Crazy theory here (and maybe a dumb one that shows my lack of knowledge...) but could the OP's amps be putting out too much current and/or wattage into the Impressions, causing the built-in bass amps to shut down at higher volumes? The 11's are rated for 20-550 watts. The EAM's are putting out 650/1000/1800 watts rms at 8/4/2 ohms. I would think the ML bass module amps would have some sort of built-in protection. Maybe that's kicking in?

Yeah, it might just be a fact that the amps in the speakers for the woofers are maxed out at a certain wattage input from the EAM amp, and then anything over that will increase the volume of the panel but the woofers dont increase their output to match?

It sounds like the speaker woofer amps dont shut down, and that they are still putting out sound. Perhaps they are maxed out but the panels will play louder?

 

[user 49888]

Ecco la cosa. Se i cavi collegati alla presa elettrica sono allentati, qualunque cosa sia collegata non otterrà piena potenza. Inoltre, può essere pericoloso se quei fili sono allentati. Se conosci un elettricista o conosci qualcuno con conoscenze elettriche, sarebbe meglio che qualcuno controlli il cablaggio.

Un test che puoi facilmente fare è disconnettere il più possibile, ma lasciare collegato il preamplificatore, un amplificatore e un altoparlante. Se succede lo stesso problema con la scomparsa del basso, allora deve essere qualcosa con l'elettrico.

Hi ttocs .. I just checked personally (even if I am not an electrician) the cables leading to the sockets (they go in and out towards each other) and they are fine.
Now I try to do the test you suggested with just an amp, speaker and dac to see if the problem remains.
I forgot to mention (I sincerely thank everyone for every suggestion received) that
- the value of the voltage measured at the entrance to my apartment almost never exceeds 214V against the 220V declared by my supplier .. unfortunately in my area it is a common problem.
- PS Audio Stellar 3 went into protection a few times due to this.
Thanks again everyone

 

[user 49888]

While waiting to carry out further tests, I wanted to say that together with the speakers I bought PBK (Perfect Bass Kit) and I calibrated the room with ARC and I must say that the general situation from an acoustic point of view has improved a lot ... moreover, for as much as I could, I spent a lot of time positioning the speakers in my room, achieving a good final balance.
For what has been said up to now and according to my perception, it would seem either a power supply problem of the amp / ML or an interface problem with the speakers which, according to what someone has suggested (Mister b and Robert D), may have some sort of protection excluding the amp.
Thanks again everyone and sorry again for my English.
Regards
Paolo

 

[user 49888]

..a small update for the moment..as suggested, I tested only on a power amp and realtive speaker but the problem persists.
The impression is that there is a sub amp cutoff or incompatibility with the power amp (trying even without ARC the problem remains).
Regards

 

[msimanyi]

Can you give us some sense of dB level (peak) when you notice the problem? If you’re hitting 98dB peaks before the problem strikes, that’s considerably different than 83dB peaks, for example.

For this info, a phone-based app would be fine. There‘s no need for exotic gear.

And… your English is easily understood! You are much more capable in English than most of us are in Italian.

 

[user 49888]

Can you give us some sense of dB level (peak) when you notice the problem? If you’re hitting 98dB peaks before the problem strikes, that’s considerably different than 83dB peaks, for example.

For this info, a phone-based app would be fine. There‘s no need for exotic gear.

And… your English is easily understood! You are much more capable in English than most of us are in Italian.

Hi msimanyl..that's right..
The problem hits at about 75/78 db.
In the evening I'll try to get off the PS Audio (where there are only CA and DAC).
Best for all

Thank again

 

[msimanyi]

Hmm. Okay, that’s not insanely loud. I’d expect the 11A speakers to easily achieve that if everything is in good order.

Hopefully that information triggers additional suggestions from other users.

Are the speakers plugged into the PS Audio regenerator? I thought your post (#5 in this thread) implied that wasn’t the case, but if they are I would definitely try plugging directly into an outlet.

 

[user 49888]

Hmm. Okay, that’s not insanely loud. I’d expect the 11A speakers to easily achieve that if everything is in good order.

Hopefully that information triggers additional suggestions from other users.

Are the speakers plugged into the PS Audio regenerator? I thought your post (#5 in this thread) implied that wasn’t the case, but if they are I would definitely try plugging directly into an outlet.

No.. I only connected the source, the DAC and the phono pre to the PS Audio.
I forgot to mention (I sincerely thank everyone for every suggestion received) that
- the value of the voltage measured at the entrance to my apartment almost never exceeds 214V against the 220V declared by my supplier .. unfortunately in my area it is a common problem.
- PS Audio Stellar 3 went into protection a few times due to this.
..what do you think?