Loud subwoofer "Hum" (1 Viewer)

[Phil Thron]

I've had a Yamaha YST-SW150 for about 6 years or so, and recently the thing has started humming very loudly after it's been on for several minutes.

I recently replaced my receiver (with a Yamaha HTR-5550, which I'm very happy with) and was hoping that perhaps the old receiver had a short or something, but in the end I'm still getting the hum. This wasn't the reason for the changeover, BTW, but I thought the situation would improve with the sub as a byproduct.

The sub's position hasn't changed, and I've checked and rechecked the wiring and everything is fine there. Is this unit shot or is there possibly some other, fixable cause?

Thanks in advance for any help

 

[Gordon Groff]

Two things to try come to mind.

1. Replace your RCA cable between your reciever's .1 out and sub.

2. Lift the ground on the power to your sub amp. Use one of those adapters for plugging into ungrounded outlets.

Let us know how you make out!
Gordon

 

[Phil Thron]

I love this forum. That was such a quick response...thanks, Gordon.

I essentially tried both suggestions:

I first unplugged the RCA cable from the sub itself and turned it on. After about 2 minutes the humming began in earnest, so I think it's within the unit itself.

I then took an adaptor such as you suggested above; I'm assuming it's one with the extra ground wire that hooks into the screw on the outlet plate. Tried it and, unfortunately, the sound persists.

BTW, upon listening again, for what it's worth, the sound is a bit more of a buzzing/hum than any kind of low, resonant humming.

Not looking good. :frowning:

But thanks for the suggestions. Always better to try some things before plunking down the money for another one...

 

[Jeffrey Noel]

Phil, this is one of the same reasons Parts Express stopped carrying the DLS 10" sub aka the Tiny Mighty. I bought one in December and the sub hummed loud just like your Yammy. I contacted them and they said it was definitely the amp and they replaced it. I don't know exactly what makes the amp do it, but you may search for an answer in the long thread from a couple of months ago regarding problems with the DLS 10". I know it's not your sub, but the problems are the same. BTW, PE let me keep the humming amp so if there is a way to fix it, let me know.

Take care!

 

[Gordon Groff]

Sorry the easy fixes didn't get it!

About fixing the noisy amp - well, I would not be afraid to get inside it and play. I watched a TV technician "fix" a hum in my TV by wrapping a rubber band around a high voltage coil!! I've also fixed them by simply wedging a piece of paper or carboard under the offending part. If you're comfortable getting inside (be safe, dude!), pull the cover and poke around with a wooden stick while it's powered and humming and see if you can find the source. Do it gently! just touching the part will quiet it!

Gordon
PS: Do this at your own risk!! I accept no responsibility or liability for smoke or fire damage nor for voided warranties or bladders if you touch the wrong thing!

 

[Phil Thron]

No problem, Gordon. The easy fixes were absolutely worth trying. And, Jeffrey, you might be right about the Amp. Sounds right, actually, now I think about it.

And it's understood, fellas, about the safety, but I absolutely appreciate being reminded. I certainly don't mind getting inside, and if I can isolate the problem, even if I can't fix it directly, perhaps I can find a replacement part instead of getting a new unit.

You guys have been extremely helpful...thanks again.