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Buzzing sound from speakers

post #1 of 13
Thread Starter 
Hi.

I've been looking for a solution to this problem for a long time.
And I'm not totally sure which forum I should put it in, so feel free to move it to another forum if needed.

First off. This buzz is not a hum. It's not low frequency.
Because of that I don't believe it is a grounding issue, which brings me to my next point.
I've tried using non-grounded outlets, which resulted in the same thing.

I'm using a 4.0 system. Dali Concept 6, Denon AVR-1909, and two older speakers. The buzz also occurs on my father's speakers Dali Ikon (number?) with Denon AVR-2808. As well as my PC speakers.

The buzz is increased when Audyssey Dynamic EQ is enabled. And the buzz is increased further more when increasing the volume.

I guess it is some type of electrical issue (so to speak). But I've tried almost everything.

- Different outlets.
- Non-grounded outlets.
- Keeping speaker-wires away from outlets.
- No input connected.
- All types of cables (HDMI, Coax..)
- Unplugged every antenna in the house.
- Tried with both Denon AVR-2808, 1909 and Onkyo TX-SR606

Quote:


The reason it showed up when Dynamic EQ came on, is that the problem was a low frequency buzz. Dynamic EQ boosts the low frequency range as you turn the master volume down to compensate for human hearing.

The thing is that. This is more like a hiss, "sssssssss", and not a low frequency like a hum "hummmmmm".

It's a kind of old house. Not every room is grounded.
Is there anything else I can try? And tips?
Been searching around the Internet a lot. And there's probably some things I've tried that I've forgotten to list here.

Guess there might not be a solution to my problem. Except renewing outlets, cables and so on (in the house).
Help is appreciated.
post #2 of 13
Not that I'm a big believer in them but as long as you can return it, a power conditioner might alleviate your problem.

Belkin is one http://catalog.belkin.com/IWCatSecti...tion_Id=202493
Uhm, Monster has them too.

* EDIT: Almost forgot about Panamax as well.
post #3 of 13
I would hold off on a power conditioner a bit.

May we have some more information. You have a hissing sound from all speakers using any receiver and any speakers and with no inputs connected. Is that right?

If you short across the inputs does the hiss stop or significantly reduce?

Does the hiss vary with changes in the volume control?

Do you have to listen from close to the speakers to hear the hiss?

Is it possible to hear the hiss when music is playing?

If the hiss is only audible at high volume settings or from very close to the tweeters, it might only be the normal noise from the amplifiers.
post #4 of 13
Thread Starter 
Quote:


You have a hissing sound from all speakers using any receiver and any speakers and with no inputs connected. Is that right?

Correct.

Quote:


If you short across the inputs does the hiss stop or significantly reduce?

I'm not quite sure what you mean with "short across" I'm afraid.

UPDATE:
I searched around a bit. And if you mean run a speaker wire by an extension cord. Then, well, no difference at all.

Quote:


Does the hiss vary with changes in the volume control?

Yes it does. And it increases a lot when enabling Audyssey Dynamic EQ (which boosts some signals).

Quote:


Do you have to listen from close to the speakers to hear the hiss?

Well, of course it depends on what volume I'm having. But I can hear the hiss at high volume, or when Dynamic EQ is enabled at normal listening level. And at that point I'm sitting around 1 meter away from the backspeaker.
As long as I don't focus on it I don't really hear it on louder scenes in movies - but it is very noticeable during quiet scenes.

Quote:


Is it possible to hear the hiss when music is playing?

Same answer as the previous question.

Quote:


If the hiss is only audible at high volume settings or from very close to the tweeters, it might only be the normal noise from the amplifiers.

Well, maybe. But then I'd say that nobody should use Audyssey Dynamic EQ with a "normal" amplifier. :P
post #5 of 13
Quote:


I'm not quite sure what you mean with "short across" I'm afraid.

it means connect the input "hot" to ground.
post #6 of 13
Quote:
Originally Posted by Glaucous View Post

Correct.

I'm not quite sure what you mean with "short across" I'm afraid.

UPDATE:
I searched around a bit. And if you mean run a speaker wire by an extension cord. Then, well, no difference at all.

Sorry for the lack of clarity. Shorting the input means just that: make a direct connection across the input jack. You could make up a shorting plug by soldering a short wire from the center pin to the outer shell of an RCA jack or short one end of an interconnect cable and plug the other in to the receiver. Switch to that input and listen for a change in the noise level.

Shorting the inputs will normally produce the lowest possible noise level and minimizes the possibility that the noise is picked up and amplified by the first stage of the preamp.

If the noise increases as the volume is increased it is likely originating in the preamp or DSP stages. A little hiss is normal, but not so much hiss that you can hear it above the dialog or music.

Audyssey should either roll off the highs a bit or attempt a flat curve; neither should add or boost hiss significantly.

If there is a pure or direct mode on your receiver does the noise level drop significantly in those modes? Is the noise level sigficantly lower in stereo mode compared to the surround modes?

Thinking about this and your original post, if you hear the same noise with two different receivers in your location what happened (or happens) if you go to a different site?

If the noise is heard at both locations in two different AVRs then I think that you are focused on normal noise or both AVRs are defective. If the noise only is heard in your location, there is a possibility of RF or power line noise.
post #7 of 13
Thread Starter 
Quote:


If there is a pure or direct mode on your receiver does the noise level drop significantly in those modes? Is the noise level sigficantly lower in stereo mode compared to the surround modes?

Yes, both pure and direct mode exists.
And yes indeed. Both of them reduces the hiss/noice A LOT. Hardly possible to hear it even when putting my ear against the speaker.

So.
Pure Direct/Direct Mode - Pretty much none, except at highest volume
Normal Stereo Mode - A bit more than Pure Direct, but only noticeable at high volume.
Audyssey Dynamic EQ - Very noticeable. Even during music.

So, it seems like when the unit is processing the signal the noise increases.
And there's no difference when using Surround Mode or Stereo.

Quote:


Thinking about this and your original post, if you hear the same noise with two different receivers in your location what happened (or happens) if you go to a different site?

Just moving it to another room doesn't really change anything. I'm planning using an extension cable to use the electricity from one of my neighbors (asking first, of course =p).


Not use I'll be able to try the short across. But I'll see what I can do.
post #8 of 13
Quote:
So, it seems like when the unit is processing the signal the noise increases.

Seems like the processing stage is introducing the noise.

Quote:
I'm planning using an extension cable to use the electricity from one of my neighbors

This could be potentially dangerous, and won't really prove anything. There's this huge DC power supply between the AC input and the speaker output.
post #9 of 13
Thread Starter 
Quote:
Originally Posted by duvetyne View Post

Seems like the processing stage is introducing the noise.

Perhaps. But it seems kind of odd that I've had two receiver and both had broken (?) processing stages.

I'll try Pure Direct on my father's receiver as well. If it is the same there, well, then I have no idea what to do.

Quote:
Shorting the inputs will normally produce the lowest possible noise level and minimizes the possibility that the noise is picked up and amplified by the first stage of the preamp.

I continued to search around, and found more people using this to defeat hiss.
And I should put one of there on every RCA input? There's frankly, a lot of them.
Looking around if it is possible to buy these (in Sweden).

I guess this is what I could use
http://www.needledoctor.com/Cardas-R...category=23892

But would I get the same effect if I just bought a normal plug (which is used for soldering)?
http://www.kjell.com/content/media/i...tems/37083.jpg
post #10 of 13
Quote:

Those are just dust caps, they don't short the input.
post #11 of 13
I suspect that you are hearing the normal noise made by digital processors. A one meter listening distance is after all much closer than most of us use, except for computer setups. I sit about 2.4 meters from my display for example.

I can't say if yours are unusually noisy or if you have acute hearing or if now that you've heard it you are fixating on the noise. I once owned a receiver that buzzed, not a loud buzz but I could hear it. It spent several weeks in the shop, on and off, but the noise remained. Finally the shop put a scope on the output and there was the noise, but it was at a really low level. Only I and one of the techs could hear it. Today I doubt I would hear it.

I really don't think that your power line is implicated. But unless you are in a locality of generally poor power quality, listening in a completely different location (not in the same building or neighborhood) should eliminate both power line born noise and RF noise from something like a nearby transmitter. I will be really surprised if using an extension cord will do anything, other than drop the line voltage very slightly.

If you are in warranty go make a fuss. If you are out of warranty you could take it in for service and get their opinion as to whether it can be fixed. You might also go to a dealer and listen to some current models and see if you hear comparable noise.
post #12 of 13
Thread Starter 
Quote:
You might also go to a dealer and listen to some current models and see if you hear comparable noise.

I'll probably do this.
Yeah, maybe 1 meter is too close. Because I tried my father's receiver, and it's the same there. The difference is that they're sitting around 2.5-3 meters away from their speakers.

Thanks a lot for all the help. Quick responses as well.
Appreciated.
post #13 of 13
Recently switched pre amps to Denon 3808/ powered by outlaw 7700 and full 7.1 surround sound Aperion Speakers; Outlaw sub.... B4 switching out pre amps I did notice a slight hum from all speakers... thinking nothing of it at the time. Well, with the denon in the mix now it seems the hum/buzz is coing from all speakers including sub! Specifically on start up--- it sounds like a freaking bee hive in my ht room! My amp and sub are on different circuits completely. I read on line about ground loop isolators fixing this problem. Any other ideas/comments; things I might try? Thxs!
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