Quad ESL help appreciated!

[Opti-cal]

Hi guys,

hope everyone is enjoying the run up to Christmas and some cozy nights in with their hifi (especially nice for the tube brigade!).

Anyway, a few weeks ago as a little treat to myself I decided to give my Quad ESL 57's a full service. Both transformers were rebuilt with new boards and all resistors and wires replaced. Both treble panels were replaced and one bass panel also. This was not exactly cheap.

Upon getting them back into my listening room and in their mm perfect positions (marked with tape), I charged them for a few hours and then began listening. Or at least I tried to. The bass output was now completely overwhelming. Boomy and uncontrolled which was killing the dynamics and imaging.

I tried a different amp and on different output taps 8 & 4 ohm but the issue was only slightly rectified using the 4 ohm taps. Plus they sounded great on the 8 ohm ones before.

Now here is my suspicion. Before the service the bass output was extremely low from the speakers enabling me to move them very close to the pitched roof in my loft where they reside. There is probably at least 3 feet of space behind most of the speaker to the back wall but where the pitched roof angles towards the back of the speaker at the top, that clearance is probably only 15-25cm.

Now I believe the now corrected bass output creates a massive standing wave reflected by this pitched roof as the design of the room previously compensated for the weak output of the bass from the speaker (and actually made it sound even more delicate than the 57 is in standard form, it really was "magic").

Does this sound plausible or am I missing something completely here?

I've tried pulling them out a bit more away from the wall but the boomy bass is still quite present but due to the small dimensions of the room I can't pull them out much more as they will be in the middle of the room!

It's at quite a specific frequency around 100-200Hz so most bass notes and drum kicks are very blurred and resonant.

It is also not from one speaker specifically (I could understand if it was from the one new bass panel) so this indicates to me there is no actual issue with the speakers themselves, more my listening environment.


The speakers are dead silent with or without source turned on and at high volume with nothing playing and I can see the new parts inside so I have no reason to suspect anything is amiss there.

Is there anything I can do to "tune", tweak or lower the bass output from the speakers? I don't really want to add an equaliser to the signal path but I will if that is the only option.

Perhaps a different resistor in the speaker somewhere in the crossover?

I've tried putting a lot of sound damping material behind the speakers (cloth panels/pillows etc) but again this only helped a little bit.

Unfortunately I don't have any tone controls on any of my amplifiers either or I'd give that a try.

I was expecting perhaps some extended break-in time for them after the service but they have been playing for the last week (probably 3 hours a day) and there hasn't been any audible improvement to my ears.


I'll be devastated if I can't get them to sound like they used to again having forked out for the service which appears to have actually made them unusable in my environment!

Any comments, help or advice much appreciated.

Cheers,

Chris

[eisenach]

Oh, dear! I'd be pretty fed up, too. Commiserations.

For what it's worth, I use 63s in a loft room and placed in a way that sounds very similar to your set-up, although I have a couple of feet of vertical wall before the roof slope takes over. I put piles of magazines and/or foam packaging behind the speakers. Anything that might help absorb the rear sound radiation. It's worth a try.

[Audio Al]

Did you rebuild them ? or done professionaly , If professionaly get back to the company and seek advice / return them as problematic

[Opti-cal]

Thanks for the reply,

I'd kill for a couple of feet! I have 63's also serviced a few months ago (not as expensive a service mind) . . .

I was surprised how well they worked in such a space actually but it looks like I have wrongly presumed that a service would improve things even further.

It is a small room with a pitched roof after all. Horses for courses as they say.

Seeing as I have tried a lot of absorption material already with minimal improvement it looks like it could be all over for the 57's in the loft . . . .

Not sure I can be bothered to wait a few years for the bass output to drop again!

My options are now, to:

a) sell a mint pair of freshly serviced Quad 57's.
b) move house to facilitate aforementioned speakers.

I think the choice is fairly clear.

[Opti-cal]

I would return (again) if I thought that was the problem Allen! Good call on giving them a ring though and seeing if they have any tips.

They were done by Quad themselves and checked meticulously.

I already returned one of them once because the bass panel was ticking slightly during charging. I'd rather it was an issue with the speakers but I fear it is the room they are in . . .

As I say in the original post as both speakers exhibit the same sound signature (which happens to not fit it with my room dimensions!) I'm fairly sure its a relocate/sell situation.

They sounded pretty decent in my lounge with some room to breath . . . unfortunately with a 7 month old rolling about down there they cannot live there permanently . . .

[Audio Al]

Is your roof 2 , 3 or 4 sided ?

[Firebottle]

I feel for your problem. I have 57's and appreciate what you are saying.

The only thing I can suggest is to have one of the bass panels disconnected to reduce the bass output.

Do not try this yourself unless very confident you know what you are doing.

[Opti-cal]

Is your roof 2 , 3 or 4 sided ?

Ceiling is 3 sided but the pitch of the roof goes nearly all the way to the floor with only a small (2 foot long) flat part in the middle before the pitched slope on the other side starts if that makes sense?

This pic should illustrate things better than my words . . .

[Opti-cal]

IMAG1167.jpgIMAG1167.jpg

[Opti-cal]

I feel for your problem. I have 57's and appreciate what you are saying.

The only thing I can suggest is to have one of the bass panels disconnected to reduce the bass output.

Do not try this yourself unless very confident you know what you are doing.

Haha, certainly one for the professionals there Alan!

Great suggestion, it might be worth looking into however I doubt I would ever be able to recreate the exact sound I had with a lower output panel with a disconnected one but its an interesting idea.

I truly didn't realise the synergy between components and room albeit with some of the components running at less than optimal to provide that sound.

It was genuinely spine tingly with proper 3D images. Probably a bit coloured and overly warm but everything was there for me. Even slam which is difficult to get out of 57's.