Help me fix my subwoofer

December 18, 2006 6:43 PM

I have a passive NHT SW2 subwoofer being driven by an NHT SA-2 amplifier that is supposed to control the volume. Lately, however, the volume for the sub plays at full, irrespective of the actual volume setting on the knob. When it first started, tinkering with the volume control could sometimes get the correct volume, but now it's just at max all the time.

It's not making any unusual sounds, it's just loud, vibrating, and completely disproportional to the sound coming out of the satellite speakers. This makes it unusable with the satellites, and the satellites are unusable without the sub, which makes my whole system unusable. Not fun.

So far:

-I replaced the cables connecting the amp to the subwoofer.
-I cleaned the volume control dial with electronic degreaser.
-I inspected the connecting wires around the volume control but see no physical problems.

I suspect that it's an amp problem, but since everything in my home stereo are separate components, it's hard for me to test this without disassembling all the parts and testing at a friends house piece by piece. That's something I would really like to avoid.

Has anyone had a similar problem? Any suggestions or directions on how to fix this would be greatly appreciated.

posted by Gamblor to technology (2 comments total)

It sounds like the volume control pot has shorted. If so, the only way to fix it is to replace the pot.
posted by Steven C. Den Beste at 7:00 PM on December 18, 2006

If so, the only way to fix it is to replace the pot.

Yes, replacing the pot often helps the music.

ba da dum tssh.

But I was going to say the same. Since fiddling with it used to fix it, that pretty well cinches that it's a problem with the amp itself - and that's a common failure mode for potentiometers.
posted by flaterik at 7:24 PM on December 18, 2006