Problem with subwoofer

[David_NC]

I picked up an old, used RBH TS-12A sub a while back. The seller included ground isolating RCA cables due to the fact that it has a hum issue. That works, mostly, but there was still a tiny bit of hum. I connected a section of wire to a screw on the plate amp of the sub to the ground terminal on my receiver, and there is no hum at all now.
I tried the usual things first - putting them on the same power strip and flipping the power plug around with a cheater adapter, but neither helped. I'd be a bit annoyed if this just started happening, but the seller informed me, and it was only $25, so I'm OK with it... especially since it's in the garage.

 

[Jim H B]

I picked up an old, used RBH TS-12A sub a while back. The seller included ground isolating RCA cables due to the fact that it has a hum issue. That works, mostly, but there was still a tiny bit of hum. I connected a section of wire to a screw on the plate amp of the sub to the ground terminal on my receiver, and there is no hum at all now.

Sounds worth a try. Sub seems to pickup interference too, from my phone, and at one point picked up police radio (at the time I chalked it up to the 25' rca cables I was running to the sub).

I'll try to run a grounding wire.

Here's a pic of the sub (stock pic). 10 inch front firing, with passive radiator in back.

 

[David_NC]

Sounds worth a try. Sub seems to pickup interference too, from my phone, and at one point picked up police radio (at the time I chalked it up to the 25' rca cables I was running to the sub).

I'll try to run a grounding wire.

Here's a pic of the sub (stock pic). 10 inch front firing, with passive radiator in back.
View attachment 1644845

It sounds like there might be an issue with the RCA cable... at least with the 25' one. I have several in use, and none pick up noise. Certain receivers / amps I've used will pick up noise from my phone when I use a specific (cheap non-Apple or any other brand name) USB adapter.

 

[Jim H B]

I hooked up a ground wire to the sub last night - didn't get rid of the hum - bummer

 

[David_NC]

I hooked up a ground wire to the sub last night - didn't get rid of the hum - bummer

That's annoying. I have to use the ground loop isolator and the ground wire to eliminate the noise. Do you have another amp or receiver you can try? It'd be nice to know if the sub or receiver is at fault. I can't recall if you mentioned if the hum was coming from the speakers or sub.

 

[hnash53]

To the OP: which brand subwoofer do you have? Powered? Passive?

Oops... just saw that you have a Klipsch sub.

 

[faber12]

Make sure your mains are wired in phase, check both ends of each speaker cable. Low frequency lack can be caused by having a speaker wired backwards.

 

[Bill Ferris]

Plug all into a power strip, this way all are sharing a common ground.

Yes Sir; Grenadeslio, worked all the time for ground loops, at least it always has for me, whether when setting up a PA, back in the day, or connecting multiple active audio equipment together in a home setup .

 

[Jim H B]

I think the problem is with the sub amp. I've tried pretty much every suggestion, but the hum persists. But as they say, a bad day working on audio gear (with the help of AKer's) beat a good day at work!

 

[Jim H B]

I am continuing to work in my 120hz drop out though. I've had some trouble with my back, which has precluded me from switching out my DLK's (they are heavy). I have switched out my amps though, with the same 120hz drop out. Either the speakers - I did double check the positive/negative wiring - or the room are at fault. Further experimentation is required!