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A/D/S L710 problem

Walnut_z

Walnut_z

New Member
I have a set of early A/D/S L710s. Cloth grills, square corners, no fuses on backs, screw terminals. They have foam surrounds and look to have been refoamed pretty recently.
One speaker sounds amazing just as it should. The other seems to be lacking bass. The woofers are both putting out sound, top one I hear midrange, bottom one I hear the lows, but compared to the tweeters they just dont seem balanced on this one speaker. Any advice before I blindly start pulling thus one speaker apart? I know there are some A/D/S geniuses in here.... is this a problem with the crossover?

They're such amazing speakers Id like to get them running the way they should.
 
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Could be a phase problem- if they were refoamed perhaps the leads were crossed when they were reinstalled. At any rate it sounds like you're going to have to pull the woofers out of the one bad speaker to have a look regardless.
 
First swap the two speakers to make sure problem is not external, such as amp.

Once sure problem is a speaker:
The two woofers of a 710 are parallel connected, so they should sound same. I suggest pulling woofers. Check they are connected with same polarity. Try swapping to see if problem moves.
 
ah.. Thanks guys, didn't think of this but it does sound like a phase issue. I have tried swapping speakers left for right, and even moved in a different amplifier and problem still existed so its definitely in the speaker. I will pull out the woofers on the speaker that seems out of phase and check the wiring. Thanks for the advice, I'll keep y'all updated.
 
Hey hey hey... little update here. A year ago I pulled the woofers and decided not to de-solder the connections or mess with them because I'm lazy and tbh, they didn't sound that bad. Ive been enjoying the L710s daily and most people don't notice the 2 speakers sound slightly different.

Fast forward to yesterday when I discovered a pretty minty set of L420s at the secondhand store. So of course I brought them home. They sound great but I can see how the L710s would be superior... so I started poking around the L710s again. I pulled the tweeters this time and lo and behold, the smallest tweeter on the odd sounding speaker was not even connected. Makes sense when you read my first post. Duh..... So I hooked up the original tweeter and got no sound. I tested with another random speaker and it did work. So... blown high tweeter eh?

So now I have some serious questions.
Should I look for a replacement tweeter?... it would be # 206 0100 for the L710 and I'm not really feelin like spending $
Should I steal one tweeter from the L420s and load it in the L710? They are different tweeters used on the 2 different models, right? Although same size.
Or should I replace tweeters on both L710s with the tweeters from the L420s and part out the remainders?

What does anyone think? I'm really having trouble deciding what I want to do.
 
Depends on the serial and which version tweeter you have. Both of the L420 tweeters used originally were superseded by the 206-0116 as a replacement part, as was the 206-0100 from the earlier L710. It's the later 710's with the 3/4" 2016-0107/2016-0117 that wouldn't match as well, but I think you can do this sub. That said, why not source replacements and keep them both functional?

John
 
hmm.. website doesnt appear to be working for me. i think i may just pillage the tweets from the 420s to keep my 710s for the simple reason I have too many sets of vintage speakers.
 
Walnut_z said:
I have a set of early A/D/S L710s. Cloth grills, square corners, no fuses on backs, screw terminals. They have foam surrounds and look to have been refoamed pretty recently.
One speaker sounds amazing just as it should. The other seems to be lacking bass. The woofers are both putting out sound, top one I hear midrange, bottom one I hear the lows, but compared to the tweeters they just dont seem balanced on this one speaker. Any advice before I blindly start pulling thus one speaker apart? I know there are some A/D/S geniuses in here.... is this a problem with the crossover?

They're such amazing speakers Id like to get them running the way they should.
Click to expand...
Foam surrounds? Did I read that right? On An Early A/D/S? That could be a problem. I have 1st Gen 810's rubber surrounds. Rebuild woofers with correct surrounds , that could be your problem, who knows what happened, the Braun woofers are nice....when original. Definitely recommend Richard So, a little hard to understand, work is top notch. I stand corrected! Here comes some help.
 
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I had a pair of the early ones, all 4 woofers were foam surrounds, and they were quite difficult to refoam. The dust caps were a strange size and shape, and the voice coil gap must've been really small, because it took ALOT of attempts to center them test tones.

More descriptions of these, they had small thumbscrew binding posts, which were difficult to replace because the crossover was mounted on a thick rear baffle, so you needed really long replacements. The corners were all sqaured, the grill was cloth stapled to a wood frame, held on by velcro. The one electrolytic cap was a 90uf (quite difficult to find), I believe some of the later ones had a 100uf.
 
jdurbin1 said:
Yes, the earliest ones had foam surrounds - four of them in all :-(

John
Click to expand...
Thanks J! I didn't Know that! I have a early set same as O.P. with rubber surrounds. I remember I removed the woofers took photos of the insides for a crossover reference. Thanks for the education...i learn new things here all the time.
 
bigx5murf said:
I had a pair of the early ones, all 4 woofers were foam surrounds, and they were quite difficult to refoam. The dust caps were a strange size and shape, and the voice coil gap must've been really small, because it took ALOT of attempts to center them test tones.

More descriptions of these, they had small thumbscrew binding posts, which were difficult to replace because the crossover was mounted on a thick rear baffle, so you needed really long replacements. The corners were all sqaured, the grill was cloth stapled to a wood frame, held on by velcro. The one electrolytic cap was a 90uf (quite difficult to find), I believe some of the later ones had a 100uf.
Click to expand...
Describing the ones I had to a T.... except rubber sourronds. My thought was a bad refoam causing drag or a rub/ sticking spot in the V.C . Clearance.1548299747257-1289839189.jpg 1548299863743-323639314.jpg
 
9EA374CF-FEFE-4AD0-9053-B875E14A24CF.jpeg I have an early L810 and had Richard redo woofers. Attached is something he found that you wouldn’t see but certainly would affect the sound quality. Speakers are 40 years old.
 
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