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Strange Buzz Problem

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R12y6a86n

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I'm having a very odd problem. I have a Grotto subwoofer hooked up to a Denon AVR-3805 receiver, and use a single subwoofer cable from the receiver to the subwoofer.

Today, I suddenly noticed buzzing coming from my main speakers, and I was able to locate the problem to my subwoofer being plugged in (power plug just into the power strip). When I unplugged the sub, the buzzing stopped. When I plugged the power back in, the buzzing started back up again. I also tried the subwoofer on standby mode, but that did not stop the buzzing. Thinking maybe the problem was related to it was the outlet it was plugged into, I tried different outlets, but the other speakers still buzzed whenever the sub was getting power.

Interestingly, the buzzing does not increase or decrease when I turn the volume up or down on my receiver. I was under the impression that the LFE out that I use was one way, so I was suprised when I found the Grotto to be the problem!

At around the same time the buzzing problem started, I also noticed much reduced bass when I tried playing music. The Grotto isn't silent when there is bass in music, but not nearly what it should be.

Does anyone have any ideas about what happened here? Before I take it in for service, is there anything I should try? Do you think this is a problem with my sub at all, or is it maybe a receiver problem (although it would be hard for me to believe since it stopped when I unplugged power to the sub)?

Thanks for any ideas you may have!!!
 

Matten Logan

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sounds like a classic ground loop problem. I think that you outlet is not wired properly or the circuit that that outlets on is not properly grounded. Call an electician.
 

wink

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R12y6a86n said:
Today, I suddenly noticed buzzing coming from my main speakers, and I was able to locate the problem to my subwoofer being plugged in (power plug just into the power strip). When I unplugged the sub, the buzzing stopped. When I plugged the power back in, the buzzing started back up again.
I would try switching out my power strip before anything else....Could possibly be a ground problem there. :cool:
 

roberto

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Matten Logan said:
sounds like a classic ground loop problem. I think that you outlet is not wired properly or the circuit that that outlets on is not properly grounded. Call an electician.
Agreed here, try a cheater plug, sometimes this work...happy listening,
Roberto.
 

MiTT

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As far as your reduced bass output with music is concerned...

I may be wrong, but if you are only driving the sub off of the LFE output from your receiver, you won't be getting much content from non-DD/DTS content. That is to say that if the source is only 2 channel vs 5.1 or 7.1 content; there isn't any .1 signal to send to the sub from the LFE output. In my home theater system (Denon Receiver & 2910 Universal player, Velodyne sub, Gallo Acoustic Micro's) I run both an LFE connection as well as running speaker cable to the sub's speaker level connections, then on to the mains. Works well for both HT and stereo.

I agree with all above on the buzz, sounds like a ground loop problem. Do you have your cable tv signal connected to your receiver? Cable providers are notorious for not properly grounding their own signals. There are a number of noise eliminator devises out there, and/or you could consider a good power conditioner (PS Audio, Hydra, Richard Gray etc).
 
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R12y6a86n

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Thanks!

Well, I think you guys are right about the outlet being bad. I had actually tried another outlet in the room before writing in my question, but I'm thinking now that maybe the whole circuit has a problem. I got one of those orange extension cords and started plugging into different outlets throughout the house, and finally found a good one in the basement. Looks like I better find a good electrician if I don't want a cord running through my house. :cool:

I'm not sure if the bass is quite what it used to be, but it could be that long orange extension cords aren't the best for this. :D Hope that bad power didn't do any damage to my equipment. So much for the Monster power filter things.

I can't thank you guys enough for writing in! You're the best.
 
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