Help! My speaker is buzzing

Hello,

I was wondering if anyone could tell me why my center speaker makes a very faint buzzing noise even though my amp is turned off and the speaker cables are disconnected. My center speaker is placed on top of my TV. Is it maybe because the magnetic shielding on my my speaker is failing? I only hear a very faint buzzing sound when the TV is turned on. It's not really noticable when I'm watching movies but if I place my ear very near the tweeter I could definately hear a buzzing noise. I thought this was very weird since the speaker isn't getting any power from the receiver. I'm guessing it has something to do with my speakers magnetic shielding. Can anyone please verify this for me? Oh yeah by the way my center speaker is a NHT super center. Thanks in advance for everyones help!

The voice coil in the speakers are probably acting as an antenna and picking up the HV scanning buzz from the TV. I find my speaker wires pick up buzzing from other components sometimes too.

Thanks Soundhound for your response. Can I ask you one more question? Then will this have a negative effect on my TV in the long run? Or I shouldn't worry about it too much.

One more thing I forgot to add to my original postl. I only have the buzzing noise problem with my Super Center. I tried placing my NHT super zero on top of the TV and it didn't have any problems.

If your speaker is totally un-shielded, it will distort the colors at the edges of the TV picture tube. You will need to eventually de-gauss the tube if this happens. Some sets do this automatically and some have a button to press to do it.

Your other speaker might be better shielded or simply more immune to picking up the signal. I would definately use a shielded speaker next to a TV receiver (or CRT computer monitor).

Maybe the speaker crossover components (inductors, capacitors, and resistors in particular) are acting like the antenna in addition to the driver coil(s). I doubt if the crossover is shielded.

Ideally, with an amp hooked up and powered on, the dynamically low output impedance of a solid state amp (dynamically low because of the use of feedback to control the output signal, this feedback decreasing at higher frequencies, raising the amp's output impedance) shorts out the siganal picked up by the "antenna" element(s) in this case. In the real world, often tweeters (and midranges too) have crossover components in series between the driver coil and the output of the amplifier. These components will lessen the amplifiers ability to get rid of these unwanted signals.

With the amp off or disconnected, the "antenna" sigal is not attenuated.

Paul

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the 1derful1

But in my case, I hear the sound with the amp turned on or off. I even disconnected the speaker cables and I still hear the sound.

Your speaker is haunted!

Paul

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the 1derful1

Oh no!! Do I have to call the Ghost Busters??

BTW, I have the same problem with my bedroom system. If any of you find a solution, let me know.

Jeff

Hi, D'Arbignal

Can you tell me if this is having any kind of negative effect on your TV? Thanks!

Jonathan,

None that I can tell. There is some slight color distortion on my set, but from an earlier unshielded speaker and not my current, shielded center channel.

Personally, I wouldn't worry about it. Is your set very expensive?

Jeff

No, Not really. It's a 30' Samsung Direct-view HDTV. But even though it's not that expensive I don't have money to burn so I wouldn't want to replace my TV. What kind of speaker do you have on top of your TV? Is it also a NHT Super Center?

No, my speaker is a Rutledge Audio Design C-1.

I understand you not wanting to damage your TV. Since it's an HDTV model, does it have a degauss feature built-in? (Some do.)

Jeff