Crossover capacitor for Bose 201

[ayeomans]

Maybe I am in the wrong section, but I am looking for advice on a crossover capacitor replacement for my Bose 201 Series II. At least I think this is probably the issue I am having. One speaker works fine and I’ve done all the basic troubleshooting but nothing at all comes out of the speaker.
So apart from that I was trying to look for a replacement capacitor, which is 3.7uf 100v inside the speaker. But for the life of me I cannot find that 3.7uf anywhere! I have read about running a couple in parallel to add up to it but is this even worth going through the effort on these? Would a parallel setup make each speaker sound slightly off or would try at even be noticeable?
I just like these speakers and repairing them just seems right to me.
Thank you!

 

[ayeomans]

Or could I get away with using a 3.3uf 100v?

 

[Eppie]

When you say one speaker works fine, do you mean the woofer still works but the tweeter doesn't? The 3.3 uf is within 10% so probably ok to try given the age of these.

 

[ayeomans]

I mean from a set of two bookshelf speakers, only one works. Maybe I am diagnosing wrong? The speakers are about 20 years old.

 

[lovinthehd]

Why do you think its the capacitor particularly? Old one leak or something? You tested each driver in the speaker?

 

[ayeomans]

Purely based on speaker age and some research that suggested for the age, the capacitors typically have run their course. And since both woofer and tweeter are not working, I was thinking it must be this. If there are better tests to rule that out than I can definitely do that.

 

[lovinthehd]

Purely based on speaker age and some research that suggested for the age, the capacitors typically have run their course. And since both woofer and tweeter are not working, I was thinking it must be this. If there are better tests to rule that out than I can definitely do that.

How did you determine both drivers aren't functioning? You disconnect them and test them separately?

 

[TLS Guy]

Maybe I am in the wrong section, but I am looking for advice on a crossover capacitor replacement for my Bose 201 Series II. At least I think this is probably the issue I am having. One speaker works fine and I’ve done all the basic troubleshooting but nothing at all comes out of the speaker.
So apart from that I was trying to look for a replacement capacitor, which is 3.7uf 100v inside the speaker. But for the life of me I cannot find that 3.7uf anywhere! I have read about running a couple in parallel to add up to it but is this even worth going through the effort on these? Would a parallel setup make each speaker sound slightly off or would try at even be noticeable?
I just like these speakers and repairing them just seems right to me.
Thank you!

A cap problem will not make a speaker produce no sound. It could make the tweeter silent, but not the woofer. You have NOT diagnosed your problem correctly.

 

[ayeomans]

Indeed. Turns out the entire right channel on the receiver is not working. So scratch this whole convo. Thanks anyways!

 

[TLS Guy]

Indeed. Turns out the entire right channel on the receiver is not working. So scratch this whole convo. Thanks anyways!

Thanks for owning up to that so we did not waste more time on it.

 

[lovinthehd]

So how did you determine it was the right channel not working? Had to ask....

 

[ayeomans]

Well there’s odd things going on with the receiver and for a bit I couldn’t even get the left channel working. After a whack from frustration the left channel came back but to e right still did not work which was also the channel that speaker was on. It’s an old receiver and probably has some worn out connections.

 

[highfigh]

Purely based on speaker age and some research that suggested for the age, the capacitors typically have run their course. And since both woofer and tweeter are not working, I was thinking it must be this. If there are better tests to rule that out than I can definitely do that.

A lot of people recommend replacing caps but in speakers, they generally don't fail unless someone fed it too much voltage and in that case, you can usually see that the cap 'exploded' or bulges at one end.

How are you testing the speaker? You can use a digital multi-meter to test the tweeter for continuity and if that's successful, you can just connect it to the other speaker's wires for the tweeter- if it works, you know the tweeter is good. Test the wire's continuity from the terminal on the cabinet to the point just ahead of the cap- if you have continuity, it's likely that the cap is bad but you can test that with a meter, too- set the meter for testing Diodes and connect the probes to the cap's wires- you should see high resistance and the value may change. Reverse the probes and test it again. if you see that it's open, replace the cap.

Parts Express has caps- you could use a 2.2uF and a 1.5uF in parallel- if you change the crossover in one side, do the same for the other.

 

[highfigh]

Well there’s odd things going on with the receiver and for a bit I couldn’t even get the left channel working. After a whack from frustration the left channel came back but to e right still did not work which was also the channel that speaker was on. It’s an old receiver and probably has some worn out connections.

Clean all of the controls and switches but also, turn it off & unplug it, get a magnifier and check for cold solder joints. These usually look like a slight circle or crescent at the base of the joint.

cold solder joint photos at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

 

[lovinthehd]

Well there’s odd things going on with the receiver and for a bit I couldn’t even get the left channel working. After a whack from frustration the left channel came back but to e right still did not work which was also the channel that speaker was on. It’s an old receiver and probably has some worn out connections.

Did you swap speaker cables was more what I was asking. If it's old enough maybe the controls/pots need cleaning. Whacking them generally not a good idea tho understandable