[Androb]

   

Spoiler: Warning: Spoiler!

 

Wow... beautiful! I have to get some of these nice vintage amps myself one day..

 

[moodyrn]

Just want to make quick post of some vintage electrostatic speakers I've been playing with the past few weeks. They are acoustat spectra 11 esl hybrids, featuring a four foot tall esl panel on top of a bass unit with an 8 inch driver. Everything I've read about them points to the esl panel being gold and the bass unit being horrible. I will say I think both are under statements.

The sound coming from the esl panel is as good as "any" electrostatic I've listened to. But the bass is just atrocious. I mean probably the worse bass I've listen too which is why probably 99% of all owners replace the driver with something else. This gave me an opportunity to play around(a lot) with winisd, and over the last couple of weeks I've gone through 5 sets of drivers. But I will say with all of the ones I've tried, modeling with winisd has been spot on with the response I've gotten from each one of them.

One of the large obstacles is the enclosure for the 8in drive was way too large at 1.639cu. In this day and time that air space is too large for many 12 in drivers. But I did end up going with a 12in that is very renown for accuracy and sound quality. I've also rebuilt the bias and power supply with some caps on the way for the crossover along with making some small adjustment to the low pass crossover so that the 12s integrate perfectly with the esl panels.

These things are now sounding like one of the best speakers I've listened to at any price. I have them four feet off the rear wall and the sound is literally coming from the back wall 4ft behind the speakers and everywhere else in the room. They are just a beautiful sounding match with my macs..... Not bad for a 25 year old esl. Much more to follow in the vintage speaker thread.




Here's a before and after of the bias and power supply rebuild






and a pic of the back of the board with all of the flux removed. For some reason this is something the manufacturer neglected to do. And this board was caked full of it.





Oh and the speaker as a whole stands at just over six feet.

 

[analogsurviver]

Just want to make quick post of some vintage electrostatic speakers I've been playing with the past few weeks. They are acoustat spectra 11 esl hybrids, featuring a four foot tall esl panel on top of a bass unit with an 8 inch driver. Everything I've read about them points to the esl panel being gold and the bass unit being horrible. I will say I think both are under statements.

The sound coming from the esl panel is as good as "any" electrostatic I've listened to. But the bass is just atrocious. I mean probably the worse bass I've listen too which is why probably 99% of all owners replace the driver with something else. This gave me an opportunity to play around(a lot) with winisd, and over the last couple of weeks I've gone through 5 sets of drivers. But I will say with all of the ones I've tried, modeling with winisd has been spot on with the response I've gotten from each one of them.

One of the large obstacles is the enclosure for the 8in drive was way too large at 1.639cu. In this day and time that air space is too large for many 12 in drivers. But I did end up going with a 12in that is very renown for accuracy and sound quality. I've also rebuilt the bias and power supply with some caps on the way for the crossover along with making some small adjustment to the low pass crossover so that the 12s integrate perfectly with the esl panels.

These things are now sounding like one of the best speakers I've listened to at any price. I have them four feet off the rear wall and the sound is literally coming from the back wall 4ft behind the speakers and everywhere else in the room. They are just a beautiful sounding match with my macs..... Not bad for a 25 year old esl. Much more to follow in the vintage speaker thread.




Here's a before and after of the bias and power supply rebuild






and a pic of the back of the board with all of the flux removed. For some reason this is something the manufacturer neglected to do. And this board was caked full of it.





Oh and the speaker as a whole stands at just over six feet.

Great. ESL is absolutely the way to go. 
 
Beveridge. The "upside down" ESL, if you will. The lowest distortion speaker on the planet - by order(s) of magnitude ...
 
Then several light years - nothing.
 
Then also refurbished/modified properly driven Acoustats can step into the picture. Of the "below Beveridge class", probably the most affordable these days.
 
Congrats on the good job. Enjoy them !
 
( but I would anticipate ANY manufacturer of high voltage electronics to clean the flux residue and not leave that to the user ...)

 

[moodyrn]

I've always loved esl and thought they were the cleanest, purest sounding most accurate speaker types. It's nice not to have to listen to the box if you know what I mean. You never realize how colored any conventional speaker is until you listen to an esl right beside it. With that said, I'm about to fire up the moody mobile to head to Huntsville to pick up a pair so of speakers many say should be on every audiophile's bucket list to own at least once. But on the bad side, only one of them is working. But I think it will definitely be worth it to get it repaired.

 

[SpeakerBox]

Another issue that can contribute to bad bass is using too high of a wire gauge in any inductor in series with the woofer (i.e. as part of the xover).  In speakers I have built I have taken to using 14awg mag wire to wind my coils (air core to avoid hysteresis).  Otherwise the added resistance will trash your damping factor (transient response out the door).

 

[musicman59]

I've always loved esl and thought they were the cleanest, purest sounding most accurate speaker types. It's nice not to have to listen to the box if you know what I mean. You never realize how colored any conventional speaker is until you listen to an esl right beside it. With that said, I'm about to fire up the moody mobile to head to Huntsville to pick up a pair so of speakers many say should be on every audiophile's bucket list to own at least once. But on the bad side, only one of them is working. But I think it will definitely be worth it to get it repaired.

You are killing me.. what are those????

 

[analogsurviver]

I've always loved esl and thought they were the cleanest, purest sounding most accurate speaker types. It's nice not to have to listen to the box if you know what I mean. You never realize how colored any conventional speaker is until you listen to an esl right beside it. With that said, I'm about to fire up the moody mobile to head to Huntsville to pick up a pair so of speakers many say should be on every audiophile's bucket list to own at least once. But on the bad side, only one of them is working. But I think it will definitely be worth it to get it repaired.

MANY times i wish i did not audition the Beveridge  - in 1979. Ever since, no matter how good any other speaker might be, sooner than later the dreaded question pops up " HOW would this music sound on the Bev ?" ...
 
With EU regulations, the good Bevs ( the ones with direct drive high voltage tube amps, NO transformer in the signal path ) got banned from importing into EU. So, even in case I scrape somehow together the ( anything but insignificant, see http://www.bevaudio.com/ ) doe required, I STILL can not have them.
 
Unless moving to non EU terrritory....

 

[moodyrn]

Another issue that can contribute to bad bass is using too high of a wire gauge in any inductor in series with the woofer (i.e. as part of the xover).  In speakers I have built I have taken to using 14awg mag wire to wind my coils (air core to avoid hysteresis).  Otherwise the added resistance will trash your damping factor (transient response out the door).

Very true. There was an EE guy who thought the same thing and built a zobel network to even out response the great success. That's the first thing I did, and it did help a great deal. The bass was a lot less boomy and integrated much better with the esl panel. But there's no fixing a cheap 3.00 woofer. The sound quality was still horrible. If I showed you a pic of it, you would know what I mean. The magnet is literally the size of a neo magnet, and the paper cone is as thin and flimsy as a brown paper bag.

You are killing me.. what are those????:rolleyes:

Lol, ok I'll let the cat out of the bag. It's a pair of first gen quad esl 57 from 1969. The owner is a guy 80 years old who bought them new when he was stationed in Germany in 1970. He still have all of the original paperwork.

 

[moodyrn]

MANY times i wish i did not audition the Beveridge  - in 1979. Ever since, no matter how good any other speaker might be, sooner than later the dreaded question pops up " HOW would this music sound on the Bev ?" ...

With EU regulations, the good Bevs ( the ones with direct drive high voltage tube amps, NO transformer in the signal path ) got banned from importing into EU. So, even in case I scrape somehow together the ( anything but insignificant, see http://www.bevaudio.com/ ) doe required, I STILL can not have them.

Unless moving to non EU terrritory....

That's a speaker I would love to hear and unfortunately probably never will. At least you get a chance to taste them. Better to have loved and lost than to never have loved at all.

 

[SpeakerBox]

I lived with ESL 57s for my entire Bachelors degree at RIT.  My roommate owned a pair.  The best mid-range ever!!!.  They were the heart of the HQD (Hartely/Quad/Decca) recommended my Mark Levinson (our dorm system only had the quads - no HQD for us poor college students ).  The Hartley woofers were 24" in diameter and many times mounted in the floor to use the basement as a box.

 

[SpeakerBox]

By the way - a Zobel network won't fix the high resistance in a xover coil (damping factor still the same or worse).  It will help flaten response though.

 

[moodyrn]

The coil resistance is 2.5 ohm. They also added an additional 4ohm resistor just after the coil. I removed it, and it made them even worse. Also, I talked to one of their engineers who still post on their forum who said the 2.5 resistance at the coil was by design to mate well with the woofer. But the 4 ohm resistor after the coil is now gone because it didn't play nice with the replacement woofers.

 

[SpeakerBox]

Yes, it is possible that the resistance of the coil is used as part of the crossover (i.e. maybe the woofer had a 5.5 ohm resistance and they add the 2.5 ohms to give them 8 ohms).  I have seen that done before.

 

[Silent One]

Lol, ok I'll let the cat out of the bag. It's a pair of first gen quad esl 57 from 1969. The owner is a guy 80 years old who bought them new when he was stationed in Germany in 1970. He still have all of the original paperwork.

Congrats on your find and your effort! I see the moody mobile is gassed and waxed... again.

 

[Silent One]

  MANY times i wish i did not audition the Beveridge  - in 1979. Ever since, no matter how good any other speaker might be, sooner than later the dreaded question pops up " HOW would this music sound on the Bev ?" ...
 
With EU regulations, the good Bevs ( the ones with direct drive high voltage tube amps, NO transformer in the signal path ) got banned from importing into EU. So, even in case I scrape somehow together the ( anything but insignificant, see http://www.bevaudio.com/ ) doe required, I STILL can not have them.
 
Unless moving to non EU terrritory....

 I just discovered BevAudio is only some 125 miles north in Santa Barbara. I might have to push my luxo sedan up the coast and get thy understanding of stats!