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GearHungry
04-27-2011, 06:43 PM
I have an older set of Altec Lansing computer speakers, with subwoofer. On one of the satellites, the mid-range speaker quit. I measured infinite resistance, no continuity between the speaker terminals (after disconnecting the tweeter leads), so I know it's the coil, and need to either get inside it to solder it back together, or buy a new speaker or two (just so they match).

I already tried prying the speaker apart to get to the coil, but it seems a pretty tight press fit, and I'm willing to give it up if I can just buy some/one.

The speaker in question is from an Altec Lansing ACS48 computer speaker system. The numbers on the back of the speaker itself are as follows:

A2156
4 ohm
980506

It's a 3" diameter cone.

Thanks for any responses. :)

JBL 4645
04-27-2011, 08:26 PM
Id have another go. I just looked at picture and it looks fairly simple item to disassemble.

GearHungry
04-28-2011, 04:07 AM
I’d have another go. I just looked at picture and it looks fairly simple item to disassemble.

I'm not talking about the speaker enclosure, with the grill and all, that holds both the mid and the tweeter, but the speaker (component) itself. I've already taken apart the satellite enclosure and removed the speaker. That's how I found the model number and impedance rating of the mid speaker itself.

I'm thinking (though I've never tried this before) if I just pry the metal can apart, the is part of the speaker, not the cone part, but the metal can that holds the magnet/coil assembly, I could possibly find wherever it is that the coil has separated, or burnt open, and simply solder it together at that point, fixing the speaker. Then I would have to press the can back together, and solder the speaker leads back in parallel with the tweeter leads, onto the speaker cable that plugs into the other satellite. Of course, after prying the can apart, I might find the job impossible, or more difficult than it seems, as the coil wire may be too fine to deal with or re-solder. Not having done it before, at this point, it's all guesswork.

The easier choice would be to find a replacement component, the actual speaker, part no. A2156, or a satisfactory equivalent in a 3" cone/4 ohm coil.

GearHungry
04-28-2011, 04:15 AM
I'm not talking about the speaker enclosure, with the grill and all, that holds both the mid and the tweeter, but the speaker (component) itself. I've already taken apart the satellite enclosure and removed the speaker. That's how I found the model number and impedance rating of the mid speaker itself.

I'm thinking (though I've never tried this before) if I just pry the metal can apart, the is part of the speaker, not the cone part, but the metal can that holds the magnet/coil assembly, I could possibly find wherever it is that the coil has separated, or burnt open, and simply solder it together at that point, fixing the speaker. Then I would have to press the can back together, and solder the speaker leads back in parallel with the tweeter leads, onto the speaker cable that plugs into the other satellite. Of course, after prying the can apart, I might find the job impossible, or more difficult than it seems, as the coil wire may be too fine to deal with or re-solder. Not having done it before, at this point, it's all guesswork.

The easier choice would be to find a replacement component, the actual speaker, part no. A2156, or a satisfactory equivalent in a 3" cone/4 ohm coil.

Here's approximately what I'm talking about:

http://www.parts-express.com//pe/showdetl.cfm?&Partnumber=289-084

JBL 4645
04-28-2011, 04:49 AM
The soldering should be simple if you have a steady hand and good light in the room. Poor light gets a poor job done.

GearHungry
04-28-2011, 05:21 AM
The soldering should be simple if you have a steady hand and good light in the room. Poor light gets a poor job done.

Okay. I'm quite confident in my soldering ability. Plus, I always use an l.e.d. headlamp for light, when I'm working, no matter what the project.

I just wonder if I can pry open the can without damage to the coil. At least I think that's where the coil resides.

Oh well,,I suppose there's no way to tell unless I try. I already tried once, with a flat screwdriver, and it was too tight, and I ended up bending the metal a bit. If I go the same route again, the metal will surely have some damage, but at least it's not damage to the cone.

I don't think these things are made to be taken apart. Like so many things these days, it's only designed for replacement, not repair.

I've been studying the subject of speaker replacement on the following page: http://www.parts-express.com/resources/speaker-replacement.cfm#rel It gets quite complex, but interesting. I found this page from the following thread, on diyaudio.com :

http://www.diyaudio.com/forums/multi-way/121698-altec-lansing-acs48.html

this ^ thread is the only link I've found so far to anyone else giving a go at repairing the mid speakers in this system, but it's from 2008, and I'm not certain I can still find a speaker that will match. I'm looking at things like "frequency crossover", and "loudness", to match the speaker to the system. Now I've got to try to get the original specs on the system itself.

It's a lot of work, but they're my son's computer speaker system, and he's happy with it, because it has a wooden subwoofer enclosure, something that's hard to find these days, I guess.

Eaulive
04-28-2011, 05:38 AM
I don't think these things are made to be taken apart. Like so many things these days, it's only designed for replacement, not repair.

Even in the good ole dayes, a speaker was rarely meant to be taken apart by removing the magnet from the frame, the integrity of this assembly is critical for proper alignment.
The proper way to do it is to remove the cone from the frame, sometimes the cone can be unglued, repaired and reinstalled, but it's not an easy job.

Even if you manage to rip of the magnet from the frame, I very much doubt you will be able to repair the coil, and even if you repair the coil, I will be very impressed if you can replace the magnet back without the voice coil rubbing.

I didn't say impossible, but highly unlikely.

Before checking for a burnt coil, I would be checking directly on the cone for bad connections from the tinsel leads to the VC.

Good luck :)

GearHungry
04-28-2011, 05:54 AM
Even in the good ole dayes, a speaker was rarely meant to be taken apart by removing the magnet from the frame, the integrity of this assembly is critical for proper alignment.
The proper way to do it is to remove the cone from the frame, sometimes the cone can be unglued, repaired and reinstalled, but it's not an easy job.

Even if you manage to rip of the magnet from the frame, I very much doubt you will be able to repair the coil, and even if you repair the coil, I will be very impressed if you can replace the magnet back without the voice coil rubbing.

I didn't say impossible, but highly unlikely.

Before checking for a burnt coil, I would be checking directly on the cone for bad connections from the tinsel leads to the VC.

Good luck :)

I've already checked for continuity with a meter, between the terminals and the ends of the copper braid leads, where they join to the speaker cone. It tests okay up to that point, on both leads. From there, the leads disappear under some black substance.

I also tested for resistance across both leads, right at the point where they dip under the black stuff. It reads infinity, or and open circuit. So I know that the problem is in the coil somewhere.

hjames
04-28-2011, 06:06 AM
I don't think these things are made to be taken apart. Like so many things these days, it's only designed for replacement, not repair.


It's a lot of work, but they're my son's computer speaker system, and he's happy with it, because it has a wooden subwoofer enclosure, something that's hard to find these days, I guess.

There may be a reason parts are no longer available ...
Altec has been bought and sold repeatedly since they went under in the 80s ...

Best suggestion is to find a similar speaker (driver), swap it into the cabinet, and make the most of it ...

But I do wish you luck with tearing down and refurbing a cheaply-made driver.

Eaulive
04-28-2011, 06:32 AM
I've already checked for continuity with a meter, between the terminals and the ends of the copper braid leads, where they join to the speaker cone. It tests okay up to that point, on both leads. From there, the leads disappear under some black substance.

Under this black substance there is a solder point between the lead and the actual voice coil wire, which is probably no thicker than a hair for this kind of driver.

GearHungry
04-28-2011, 08:40 AM
There may be a reason parts are no longer available ...
Altec has been bought and sold repeatedly since they went under in the 80s ...

Best suggestion is to find a similar speaker (driver), swap it into the cabinet, and make the most of it ...

But I do wish you luck with tearing down and refurbing a cheaply-made driver.

Right. I just got a response to a query from Altec Lansing. The summary is,,"We do not provide any of the internal parts of our speakers as spares." So, they offer no assistance. It's on me.


Under this black substance there is a solder point between the lead and the actual voice coil wire, which is probably no thicker than a hair for this kind of driver.

Thanks. Maybe I'll just see if I can't do some fine work, under the "black substance",,