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#71003 - 10/19/06 09:26 PM Thumping sub-woofer  
bwise121  Offline
Member
Joined: Sep 2003
Posts: 114
Sacramento, CA USA
I installed a decent Home Theater in my own home. I just used an existing lighting circuit that was in the area. When I turn on a light in that room (same circuit) the subwoofer makes a thumping sound. I used quad shield RG-6 and didn't run it parallel to any electrical that was near by.

Any ideas on what is causing this?

Thanks,
Byron


Work Gear for Electricians and the Trades

#71004 - 10/19/06 10:25 PM Re: Thumping sub-woofer  
A-V Pro  Offline
Junior Member
Joined: Dec 2005
Posts: 7
Byron,
Does the power plug on the subwoofer have 2 or three conductors?


#71005 - 10/19/06 10:53 PM Re: Thumping sub-woofer  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
Switching noise? What kind of light, and what kind of switching? If just a regular switch - try a dimmer....


Mark Heller
"Well - I oughta....." -Jackie Gleason

#71006 - 10/19/06 11:57 PM Re: Thumping sub-woofer  
Lostazhell  Offline
Member
Joined: Feb 2004
Posts: 1,431
Bakersfield, CA (Originally Or...
Electronic Ballast? Could it possibly be causing harmonics on the neutral? Cheapest solution since you're an EC might be a dedicated circuit for the AV equiptment..
But if you're really into spending cash, there's a link around here someplace to some faceplates that are supposed to make your system sound better [Linked Image] [Linked Image] [Linked Image]
https://www.electrical-contractor.net/ubb/Forum1/HTML/007372.html


#71007 - 10/20/06 01:44 AM Re: Thumping sub-woofer  
mxslick  Offline
Member
Joined: Oct 2004
Posts: 803
Atomic City, ID USA
Quote
I used quad shield RG-6


That's a problem right there. RG-6 isn't designed for use at audio frequencies, and the shield (since it's being used as an unbalanced return) is acting like an antenna.

You need to get some Belden 8451 (or it's easier to strip brother, 9451) from an electronics house. (Radio Shack used to carry a wire very similar, ask for two-conductor foil shielded cable.)

Connect it as follows: ( I'm assuming use of RCA phono plugs on each end)

Red wire: To tip on each end
Black wire: To shell (or "crown") on each end
Shield (bare)wire: To shell on one end only. Important: Make sure the shield does NOT contact the shell at all on the end opposite this connection.

You may need to experiment, but connect the end with the shield tied in on the SOURCE end first.

That should eliminate most if not all of the pop. Also, a surge protector at the sub wouldn't hurt.

And if you have money to burn, you can always get Monster cable. It'll work well but is super expensive. [Linked Image]

PM me if you have more questions/need more help.


Stupid should be painful.


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