Help diagnosing speaker problem

[jakepryor76]

Hi Everyone,

I am struggling to diagnose a problem with my right hand side speaker having tried a couple of obvious fixes.

Background

To give you a bit of background:the right hand speaker is currently producing no sound whatsoever. However, up until recently it was possible to 'crank' the volume sharply (returning quickly to a normal volume) which would temporarily bring the speaker back to life. Equally, providing a delicate (!) tap to the bass cone would also result in the speaker working. Both of these methods had only a temporary effect (15-60 secs) and now neither work.

Attempted fixes

- replace speaker cable
- replacing phono to mini jack cable
- plugging into different headphone inputs on computer
- trying different amp

Specifications/Set-up

- speakers: Mordaunt Short, Avant 902i
- amp: Technics SA-GX100L
- Plugging into new/modern PC desktop

Any thoughts would be really appreciated. The speakers aren't worth a huge amount of money these days (so wouldn't be cost effective to get them looked at), but I really like the sound they produce and I'm not a fan of today's throw away culture!

Thanks in advance,

Jake

 

[SinxarKnights]

Does the tweeter work? Assuming you tried reversing the speakers (swap channels to rule out the amp)?

If the tweeter works but the woofer doesn't, it sounds like the wires that connect to the voice coil are damaged/broken. Especially since you could do the sudden increase of volume trick (at this point it would be broken but only just), still close enough together to allow a stronger signal to bridge the microscopic gap. Tapping the woofer and it starts working is a classic sign of damaged connector wires.

If it is just the woofer that is no longer working, you could try to replace it. Not sure if you can open them up though, even if you can they may be glued or molded into place. It appears to be a 5" (130mm) aluminum cone woofer. Of course it will change the sound of it though so for best result you would have to do both speakers to match the timbre.

 

[jakepryor76]

Does the tweeter work? Assuming you tried reversing the speakers (swap channels to rule out the amp)?

If the tweeter works but the woofer doesn't, it sounds like the wires that connect to the voice coil are damaged/broken. Especially since you could do the sudden increase of volume trick (at this point it would be broken but only just), still close enough together to allow a stronger signal to bridge the microscopic gap. Tapping the woofer and it starts working is a classic sign of damaged connector wires.

If it is just the woofer that is no longer working, you could try to replace it. Not sure if you can open them up though, even if you can they may be glued or molded into place. It appears to be a 5" (130mm) aluminum cone woofer. Of course it will change the sound of it though so for best result you would have to do both speakers to match the timbre.

Thanks for the quick response. Yep tried reversing the speakers and tried a different amp so pretty confident it's a speaker problem.

Tweeter doesn't work either unfortunately. Hmm, I'm happy attempting some simple fixes (soldering etc.) but I'm guessing that any work on repairing speakers is going to be pretty finickety.

Really appreciate the response. Thanks,

 

[americanaudiophile]

The Mordaunt Shorts ain't junk so it would be good to get them working.
I would start by removing the tweeter and connecting it directly to the amp with the volume low so you don't damage it in case it's OK. Then do the same with the woofer. If they both work that's good because the problem will be in the crossover. All the wires inside the speaker will be connected to it. Look for burned resistors and or bad capacitors. If you have a VOM with capacitance you can measure them and replace the bad ones. Not expensive. If the crossover is really bad you can use the one in the working speaker as a guide.
The fact that pushing in the woofer gets it working leads me to believe that it will need to be rebuilt. In the US I suggest millersound.com Great work reasonable price. Tweeters can't be rebuilt. If the exact replacement tweeter or voice coil assembly is not available you could replace both tweeters with the closest equivalent. Madisound is very good for that.

 

[jakepryor76]

The Mordaunt Shorts ain't junk so it would be good to get them working.
I would start by removing the tweeter and connecting it directly to the amp with the volume low so you don't damage it in case it's OK. Then do the same with the woofer. If they both work that's good because the problem will be in the crossover. All the wires inside the speaker will be connected to it. Look for burned resistors and or bad capacitors. If you have a VOM with capacitance you can measure them and replace the bad ones. Not expensive. If the crossover is really bad you can use the one in the working speaker as a guide.
The fact that pushing in the woofer gets it working leads me to believe that it will need to be rebuilt. In the US I suggest millersound.com Great work reasonable price. Tweeters can't be rebuilt. If the exact replacement tweeter or voice coil assembly is not available you could replace both tweeters with the closest equivalent. Madisound is very good for that.

Thanks for the suggestion. I'm not really used to poking my head into the innards of speakers, but there is a first time for everything and I haven't really got much to lose.

As always very appreciative of the help and I'll let you know how I get on....when I get round to it of course.

Thanks,

Jake