TV making my speakers buzz -- Help!

[lungfish]

Hi all,

Not sure if this is better off here or in the TV forum, but anyway:

Just installed a set of Wharfedale Diamond 8's around my existing Panasonic widescreen TV. All is well, except that the centre speaker (sitting on top of the TV) and the right front (just about right next to it) are emitting an audible buzz whenever the TV is switched on. It's not terribly loud, but I can hear it from the sofa (about 2m away) if everything else is quiet.

I'm pretty sure the TV is the cause, since the buzz remains even if I unplug the cable from the speaker, but goes away if I move the speakers further from the TV or switch the set off. It seems higher pitched than 50Hz mains hum (definitely more of a buzz than a hum) but I did notice that the mains plug for the TV isn't earthed. Not sure if there's anything else on the same mains circuit.

Other than moving the speakers further away -- pretty much impossible with the centre and impractical with the other -- is there anything I can do to reduce this interference? I suppose it might be a fault with the TV (the set itself makes a similar buzzing sound somewhere deep inside, but most TVs seem to do that).

Many thanks in advance.

 

[Member 14718]

Dont have an answer for you but this story might make you feel better.

I was called to a UCI Cinema to try help Mike and Andre the enginneers, they had buzzing on the speakers Left, inner Left, Centre, inner Right and Right, big double 15" jobs with massive horns. They had stripped a complete projection booth out that took weeks to wire, trying to find the fault and it turned out that when they designed the place they had put the big UCI logo on the wall on the otherside of the speakers, and it induced hum into the wiring.

The cure by the way, when they show a film they switch the sign off.

Maybe some form of screening I cant think how tin foil? No! thats eastenders

 

[kevenh]

Hey! I found a twin

My Diamond 8 centre speaker sits on top of my Panny 28" widescreen, and also hums merrily when the telly is on.

I do have cheaper than cheap speaker cable connecting the centre speaker to my amp.

I need to move closer to the telly/speaker to be aware of the hum than my normal listening position but just knowing it hums means I will try cure it.

I'll keep you posted.

(oh! things to try: better cable, and re-routing it's path. Sitting the speaker on a sheet of mu-metal)

 

[lungfish]

Originally posted by kevenh
Hey! I found a twin

My Diamond 8 centre speaker sits on top of my Panny 28" widescreen, and also hums merrily when the telly is on.

I do have cheaper than cheap speaker cable connecting the centre speaker to my amp.

I need to move closer to the telly/speaker to be aware of the hum than my normal listening position but just knowing it hums means I will try cure it.

I'll keep you posted.

(oh! things to try: better cable, and re-routing it's path. Sitting the speaker on a sheet of mu-metal)

Good, I'm not alone

The really weird part is having the buzz continue after I pulled out the speaker cable... it's QED original, running right across the back of the TV cabinet, but the buzz is exactly the same whether it's plugged in or not.

I'm going to try reproducing the problem with my nasty cheap computer speakers.

 

[lungfish]

Well, I might have found a 'solution' to this problem, although I'm not really sure why it works...

I took my buzzing centre speaker over to a friend's place today, stuck it on top of his 36" Toshiba, powered up and heard... absolutely nothing apart from the transformer in the TV.

OK, so it looks like the speaker is fine and it's my TV that's causing the problem.

While I was plugging everything back together at home and trying out a few different locations for the centre (in case that made any difference), thought 'why not?' and popped the bi-wiring links off the speaker terminals... Oh wow, no more buzzing! Well, almost none: there's still the tiniest bit of noise in the centre tweeter, but nothing you could hear from more than 20cm away.

I guess the thing to try now is to actually bi-wire the speaker and see if it still behaves itself. I'll cobble something together tomorrow and report back.

In the meantime, any expert out there care to hazard a guess as to why pulling those links off would have made such a difference?

Scott

 

[kevenh]

Hi Lungfish!
Thanks for the feedback.
I haven't looked at mine yet. Sorry I'm not pulling my weight - I swapped out my Tosh 2109 for a Tosh 220 instead

Have you replaced the metal clip thingy with anything else?
Are you temporarily running with just treble or just bass?

I might try removing the metal plate on my centre speaker and replacing with a short length of speaker cable*.

Cheers.

(* - that's a good tip for any of your speakers were you have those metal clip thingies instead of bi-wire.)

 

[lungfish]

Originally posted by kevenh
Hi Lungfish!
Thanks for the feedback.
I haven't looked at mine yet. Sorry I'm not pulling my weight - I swapped out my Tosh 2109 for a Tosh 220 instead

Have you replaced the metal clip thingy with anything else?
Are you temporarily running with just treble or just bass?

I might try removing the metal plate on my centre speaker and replacing with a short length of speaker cable*.

Cheers.

(* - that's a good tip for any of your speakers were you have those metal clip thingies instead of bi-wire.)

No worries -- my Pioneer DV-656A won't be arriving until the end of the month so I'm occupying myself until then sorting out all my speaker problems

I haven't tried anything yet apart from quickly connecting one of my front cables between the amp and the second set of terminals on the centre to see if that brought the buzz back (it didn't).

Tonight I'll assemble a bi-wired cable from a couple of my existing cables to make sure things are still OK when the terminals are linked again at the amp end. If that works I guess it's back to the shop for some more cable and some proper bi-wiring.

Will also try your suggestion of replacing the metal links with a bit of real cable.

Scott

 

[lungfish]

Well, no joy there -- the buzz came back as soon as the bi-wired cable was connected, regardless of whether the other end was plugged into the amp, or whether the amp was switched on.



I'm open to any other suggestions for ways to eliminate (or even just reduce) this noise.

Scott