I have a pair of Speakerlab S7 speakers that I bought as a kit in 1978, gave away in 2006, and have recently re-acquired. They have been abused (dropped) while not in my possession. When they were recently given back to me, one speaker was dropped hard enough to have the 12" woofer popped out of its RTV nest, and it appears the big mid-range resistor tore out the connection to the capacitor in that circuit during that event. I hooked up the one complete speaker that still seems intact and heard that wonderful sound that I loved so much years ago. I have decided to attempt repairs, as I would like to enjoy their sound for the time I have left, so am asking for any hints, tips, guidance in getting the heavily damaged speaker talking again.
It appears that one of the crossovers was damaged in that the lead from the 12uF 100V non-polar capacitor [Rubycon] (picture below) was torn out of the capacitor body. Paul Johnston from The Loudspeaker Store was kind enough to respond to my e-mail and get me started on the parts quest and not make the process complicated. My need is simple: I just want to get this damaged speaker working enough so it can work together with its aged (but apparently intact) partner for a little while. I would like to get close to the original specs in replacement before I seal up the cabinet with RTV. I don't have a "listening room" any more, but will simply stack the two and leave them wherever I can find room in my tiny office where I hide out. Won't be able to muscle these 95 pound beasts around much longer without help.
Getting the old RTV off of the woofer cabinet face is a challenge without tearing up the MDF mounting board - any hints other than being extra careful in peeling this nearly 50-year old stuff off without destroying the MDF?
I was planning on using RTV silicone to button things back up once it produced sound again - all the individual horns and woofers seem intact, and produce sound when tested. Hoping there is enough lip left on the MDF board for that woofer to hang on to. I will be heeding the advice of others here and refrain from hot melt glue. I am not in a good enough shape to install hardwood backer for T-screws. I suppose it's RTV and pray... any other thoughts appreciated.
RB in flyover country USA - Mountain time
It appears that one of the crossovers was damaged in that the lead from the 12uF 100V non-polar capacitor [Rubycon] (picture below) was torn out of the capacitor body. Paul Johnston from The Loudspeaker Store was kind enough to respond to my e-mail and get me started on the parts quest and not make the process complicated. My need is simple: I just want to get this damaged speaker working enough so it can work together with its aged (but apparently intact) partner for a little while. I would like to get close to the original specs in replacement before I seal up the cabinet with RTV. I don't have a "listening room" any more, but will simply stack the two and leave them wherever I can find room in my tiny office where I hide out. Won't be able to muscle these 95 pound beasts around much longer without help.
Getting the old RTV off of the woofer cabinet face is a challenge without tearing up the MDF mounting board - any hints other than being extra careful in peeling this nearly 50-year old stuff off without destroying the MDF?
I was planning on using RTV silicone to button things back up once it produced sound again - all the individual horns and woofers seem intact, and produce sound when tested. Hoping there is enough lip left on the MDF board for that woofer to hang on to. I will be heeding the advice of others here and refrain from hot melt glue. I am not in a good enough shape to install hardwood backer for T-screws. I suppose it's RTV and pray... any other thoughts appreciated.
RB in flyover country USA - Mountain time
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I've pulled speakerlab off MDF before. It is very doable. Use a razor cutter and gently go around the speakers applying some upwards pull with a thin blade screwdriver or some other method to pry up. The wider the pry the better, the thinner the better. It can take an hour or so to pull off a speaker. I have some W1208's (4) two have tears in the butyl and 2 are pretty intact. They were a brute of a woofer. I miss speakerlab, well the speakerlab of the 70's.
Wow, a few of us SpeakerLab fans out there (from the 70's). Good for us. I built a set of the big horns that they had and never forgot how great they sounded. I agree with the removal by way of either a thin screwdriver or sometimes even a razor knife will do it. No matter which, much care should be taken or you will end up with a harder job than you first imagined. The 7's were a really cool model. Too bad someone trashed them the way that they did.
The best precise scraper is a wood chisel. Sold in sets of 1/2" wide, 3/4" wide, 1" wide, at home stores. You can tap gently on the plastic head with a small hammer to provide force. I put the straight edge on top and hold it so the angled edge is flush with the surface I am trying to remove gasket material from.
Perhaps soften the stuff with lacquer thinner? It'll work on most any substance ... a vapour mask and nitrile gloves are in order, though.
Sometimes adhesives just work too well. I saw someone make a mistake by using an adhesive tar-based sheet cut to the driver mounting dimensions. No, it did not come off in one piece. Sure was sealed nicely though.
A follow-up: the front panel MDF mostly disintegrated when I peeled the RTV off as carefully as I could (manual, NO solvents!), so this looks like a major tear-apart and rebuild to me. While I was able to find a replacement capacitor and install it, the remaining reconstruction work was more than I want to take on. So these have gone to the recycle bin, I enjoyed the memories of better times.
Thanks for your inputs on this potential project.
Thanks for your inputs on this potential project.
I've never understood using silicone sealants on drivers, for exactly these reasons. They're nearly impossible to remove without damaging things, and as long as the box is made reasonably to begin with, the seal improvement is negligible. I normally use super soft foam weatherstripping, and even its tendency to stick a driver down annoys me periodically.
If some kind of isolating mount is desired, I'd look for a different approach. To me, the risks of silicone far outweigh the benefits.
If some kind of isolating mount is desired, I'd look for a different approach. To me, the risks of silicone far outweigh the benefits.
When I didn't know any better, silicone was the go to adhesive. Now days, I am satisfied using a decent gasket and making sure that the mounting screws are up to the job. Even use T-nuts in some cases.
From what I saw of those photos, it looks like the cabinets took a real beating, especially if components were jarred loose from solder connections! I might have been tempted to keep the drivers, but what then? If you are not able to construct new cabinets, they gather dust somewhere.
From what I saw of those photos, it looks like the cabinets took a real beating, especially if components were jarred loose from solder connections! I might have been tempted to keep the drivers, but what then? If you are not able to construct new cabinets, they gather dust somewhere.
Everything is scheduled to go to the annual landfill trip in May along with a bunch of other stuff that is no longer needed in my advancing years. They can join the spirit of my Dad's 1962-vintage AR-2a speakers and Fischer system that went away at the turn of the century when he passed on. Am in flyover country, nearest town is an hour away, and no cities within any distance I'd want to drive, I doubt there is any interest this old stuff beyond nostalgia by those who experienced it 'back when'.
'Cheers'
ahrbee,
I am impressed that you have the sense that you do about this. Your exactly correct about this being 'nostalgalistic'. I have in some cases kept absolute crap for years without good reason other than that. Then I moved seven more times. I still have some crap to throw away, but realistically, nobody, not even the recycle center, gives a crap about an old camera that millions were made and nobody sells film for anymore. And so much more.
As far as living in a fly over area/state, we are probably neighbors and don't know it. Getting anything shipped around can be serious business, so for those who don't know, a pay for what it's worth (to ship plus some) policy would still bring hesitation. Having said that, would you consider say an offer on those Speaker lab horns? Seriously, I am only curious with not too much real interest, but maybe someone would be brave enough to make a generous enough offer for any/some of this. If I have overstepped my assumptions, I apologize.
I am impressed that you have the sense that you do about this. Your exactly correct about this being 'nostalgalistic'. I have in some cases kept absolute crap for years without good reason other than that. Then I moved seven more times. I still have some crap to throw away, but realistically, nobody, not even the recycle center, gives a crap about an old camera that millions were made and nobody sells film for anymore. And so much more.
As far as living in a fly over area/state, we are probably neighbors and don't know it. Getting anything shipped around can be serious business, so for those who don't know, a pay for what it's worth (to ship plus some) policy would still bring hesitation. Having said that, would you consider say an offer on those Speaker lab horns? Seriously, I am only curious with not too much real interest, but maybe someone would be brave enough to make a generous enough offer for any/some of this. If I have overstepped my assumptions, I apologize.