Wharfdale sw-250 issue. Help with a repair?

[The Jay]

Hi, new here but have an issue with this sub and I'm hoping someone can maybe help with enough guidance to diagnose and repair this myself. I've never tested circuit boards but I come from the world of car audio and have always done all my own work there so while a novice at this task I'm hoping I can pull this off.

Every so often, the sub makes noise with or without input. There are two sounds that it will emit at the same time, a kind of noise like when you were a kid and breathed on a window in the winter to fog it up,and at the same time, quiet popping. I think collectively it sounds like a dragon gargling really quietly.

Typically I turn it off and leave it a few days and then it's good to go again but now it's gotten more frequent.

I'm not having any luck getting an idea of what it might cost to repair. Everyone is really vague and no one has said "oh I've seen this before it'll likely cost $x", which is what I had hoped for. See I just shelled out a few hundred to save my 3D plasma cause I'm not ready to go 4K yet, and I'm building a new system in the basement and would rather save cash for that. Or in the worst case scenario, I'd like to wind up on the better end of a repair/replace dillema.

Would anyone have any idea what might be causing this or what I can do to diagnose and then hopefully fix?

Thanks for any advice you have.

Jay

 

[TLS Guy]

Hi, new here but have an issue with this sub and I'm hoping someone can maybe help with enough guidance to diagnose and repair this myself. I've never tested circuit boards but I come from the world of car audio and have always done all my own work there so while a novice at this task I'm hoping I can pull this off.

Every so often, the sub makes noise with or without input. There are two sounds that it will emit at the same time, a kind of noise like when you were a kid and breathed on a window in the winter to fog it up,and at the same time, quiet popping. I think collectively it sounds like a dragon gargling really quietly.

Typically I turn it off and leave it a few days and then it's good to go again but now it's gotten more frequent.

I'm not having any luck getting an idea of what it might cost to repair. Everyone is really vague and no one has said "oh I've seen this before it'll likely cost $x", which is what I had hoped for. See I just shelled out a few hundred to save my 3D plasma cause I'm not ready to go 4K yet, and I'm building a new system in the basement and would rather save cash for that. Or in the worst case scenario, I'd like to wind up on the better end of a repair/replace dillema.

Would anyone have any idea what might be causing this or what I can do to diagnose and then hopefully fix?

Thanks for any advice you have.

Jay

Unfortunately this is all too common in class D sub amps. These amps are just horrible to trouble shoot and service. This problem arises from the switching power supplies.

You might get away with recapping the power supply, but that far from always does the trick.

Your best bet is to buy a new plate amp. You will have to do carpentry to make sure there are no air leaks.

Servicing these plate amps is pretty much never cost effective.

I would not use that sub, as these problems are known to result in incendiary events now and again.

 

[MrBoat]

Does the plate amp get warm/hot? Reason I ask is, you say when you leave it off for awhile it goes away. Something similar happened to an integrated amp I had. After it would warm up, it would act up. Come to find out, there was a slightly loose connection on a relay, and when the amp would get hot, things would expand and the connection would become just enough loose to cause an issue. I tightened all the screws, and found a couple questionable solder joints and reflowed them just incase. I never was sure which part was actually causing the issue but it stopped regardless.

The first part of DIY is taking the thing apart and looking to at least see if you may find something obvious.

 

[The Jay]

Thanks for the replies. It doesn't get any warmer than normal operation. And a lot of the time I turn it on from cold and it's like this.

When I say I shut it off and leave it I mean for a couple or a few days.

Thanks for any help with this.

 

[MrBoat]

Thanks for the replies. It doesn't get any warmer than normal operation. And a lot of the time I turn it on from cold and it's like this.

When I say I shut it off and leave it I mean for a couple or a few days.

Thanks for any help with this.

Subs vibrate a lot. I never really understood installing the electronics right on them without any decoupling, just for longevity sake. Is why I thought maybe to suggest taking it apart and having a look and checking all the connections at least.