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Post by rexton on May 3, 2020 10:03:36 GMT
Hi everyone I hope you can help. I've been looking into updating my Quad ESL 57's. I got the service history from One Thing Audio. They were last fully serviced in June 2010. There has been some suggestion that the Bass panel might by down on output. To be brutally honest the 57's hardly get used and were bought on a whim. I originally intended moving to be a bigger house and then start using them. This never happened . So, as you all know I love to restore things and I have thought about replacing the bass and treble panels with the more efficient products from OTA, this would make an excellent project, however, I also just feel like sending them off and getting them fully overhauled. I'm at a loss to understand how the bass panels may be down on output considering they have hardly been used. Could anyone explain this phenomenon? I've not fired them up for a year or so. I'm doing my research first before I make any rash decisions. That's why I'd like to understand a little about bass panel deterioration. I understand that the bass panels can lose their diaphragm coating over a period of time. Some have suggested 10-15 years. I appreciate I will get suboptimal bass output if the diaphragm is compromised or worn down. It's the deterioration process in the bass diaphragm that interests me. The speakers are stored in a warm environment and barely used, perhaps less than 50 hours, yes it's a crime, sorry! Finally is there any way of measuring bass panel output?
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Post by firebottle on May 3, 2020 10:12:13 GMT
Storing in a dry environment is the best approach.
Measuring the 6kV EHT needs specialised equipment but is a good indicator of whether the bass panels are 'firing on all cylinders'.
I have a high voltage probe (ooh err).
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Post by rexton on May 3, 2020 10:17:36 GMT
Shame your in bloody Brum and this sodding COVID19 lockdown.
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Post by sq225917 on May 3, 2020 11:16:44 GMT
Andy,
For the record, your room has nowhere near enough space for quads to 'work'.
That said, I'd ignore suggestions that there may be something wrong with your quads and actually measure the damn things, in the garage, one at a time. Then decide if anything needs fixing.
Honestly though mate, I've never heard 57's deliver their full bandwidth in anything less than a 15 foot wide room, and ideally with more depth behind them than width.
If you heard Angus's set at last years wam show youd know what I meant.
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Post by rexton on May 3, 2020 11:20:13 GMT
Yes, sadly they were purchased for a bigger house. Here's OTA service report.
The service we carried out at the time would’ve been : -
2 x Treble panel rebuild
2 x Eht unit
2 x Clamp board
The components in the audio transformer updated.
The bass panels were within spec at the time.
The only thing likely to have changed by now is the
Performance of the bass panels.
Given past experience they are probably well down
In output by now.
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Post by firebottle on May 3, 2020 11:25:30 GMT
Hmmm. I have never had my bass panels 'serviced' and they are now around 46 years old. I have exceedingly good bass response.
I have replaced the EHT units though.
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Post by rexton on May 3, 2020 12:58:30 GMT
Alan, have you any idea what serial numbers are on the 57's? Did you buy them new? I'd like to see how old mine are.
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Post by jandl100 on May 3, 2020 13:17:42 GMT
Why not call up Quad in the UK?
Not sure if they'll be working atm, but if they are I bet one of their engineers would be happy to chat.
... do they still have engineers in the UK, and would they know owt about the old '57?
One way to find out!
CONTACT INFO
Quad Hifi
IAG House, 13/14 Glebe Road. PE29 7DL
+ 44 (0)1480 452561
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Post by firebottle on May 3, 2020 14:07:36 GMT
Bought second hand, one has Serial 22440. I believe they were made around 1974, certainly early 70's.
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Post by rexton on May 3, 2020 16:23:09 GMT
Guys, thanks for all your help.
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