backround noise from speakers

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AzN jonzOrz
Posts: 46
Joined: Tue Sep 02, 2003 4:04 pm

backround noise from speakers

Post by AzN jonzOrz » Thu Dec 04, 2003 5:04 pm

I recently bought some monsoon mh-505 surround sound speakers. Right when i powered them up, i realized they have loud buzzing. I don't know if this is normal or because of some kind of interference. Anyone know if this is normal?

kie
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Location: UK

Post by kie » Thu Dec 04, 2003 5:17 pm

is the buzzing coming from the speakers themselves or from the power supply?

I would have thought that speakers should not buzz. Actually, even speaker power supplies should not buzz (imo). If the speakers are not designed for use with computers, they are unlikely to be shielded and so the buzzzing could be due to interference.
Do they buz when the computer is off? If so then the buzzing is unlikely to be due to interference (unless oyu have other electrical eqipment nearby) and I would suggest returning and replacing them.

Just my thoughts...

wsc
Posts: 161
Joined: Sat Jun 21, 2003 9:25 am
Location: Oklahoma

Post by wsc » Thu Dec 04, 2003 5:36 pm

A hum coming from your speakers can be very difficult to pinpoint and solve. It can be due to the fact that your computer's power supply produces alot of noise because of it's switching design, and this noise propegates to the audio signal and results in a "hum"... or it can be due to a ground loop. Basically a ground loop means that there is a current flowing through the speakers because of a minute difference in the potential between the grounds of all your equipment. So there's two things you should try doing (IMHO):

1 - while the speakers are powered up, plug their input into a different source (like a discman or a portable MP3 player or something) and see if the hum goes away. Also see if the hum goes away when the input is left unconnected.

2 - try plugging both your computer and the speakers into the same outlet to see if you can eliminate the ground loop.

Edit: also you might try doing all combinations of #1 and #2 just to try and further pinpoint the source of your problem if at all possibe. If doing all of that yields no results.... well, hopefully someone more informed than me can step in and offer some better adivce ;)

AzN jonzOrz
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Post by AzN jonzOrz » Thu Dec 04, 2003 7:55 pm

the buzzing sound happens when the speakers are plugged in to the power outlet. It continues even when i disconnect them from any source for sound. The buzzing only comes from the flat panel speakers and not the center. The center is a traditional cube driver.

AzN jonzOrz
Posts: 46
Joined: Tue Sep 02, 2003 4:04 pm

Post by AzN jonzOrz » Thu Dec 04, 2003 7:57 pm

I can turn off my computer and only run power to the speakers and the sound still comes out. Its not the normal "hiss" that you would hear from "normal computer speakers". By the way, these are designed for use with computers. The buzz does not increase in volume when the master volume is increased if anyone was wondering.

And just to clarify, i can't return these because i bought them on ebay :(

kie
Posts: 105
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Location: UK

Post by kie » Fri Dec 05, 2003 4:30 am

Well if the buzz is still there when there is no electrical operating nearby, then you must have defective speakers... sorry :(

At least contact the ebay seller and see what they have to say. At the worst, I guess you'll just have to leave negative feedback.

CRT_Leech
Posts: 48
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Post by CRT_Leech » Wed Dec 10, 2003 9:55 am

If your soundcard supports Digital S/PDIF output, buy a set of Digital speakers. I've been running digital speakers for over three years now and they are completely silent at any volume, if there is no input.

Good luck,
CRT_Leech

wsc
Posts: 161
Joined: Sat Jun 21, 2003 9:25 am
Location: Oklahoma

Post by wsc » Wed Dec 10, 2003 12:14 pm

AzN jonzOrz wrote:The buzzing only comes from the flat panel speakers and not the center. The center is a traditional cube driver.
Sorry man, that sounds like a problem that is intrinsic to the design of the speakers... :(

If I were you I would just try to sell them to someone who won't care about the buzz...

Edit: wait now that I think about it, it *may* not be a problem with the speaker set itself. But any hum I've ever heard was low enough in frequency that it came from the low range drivers (ie, the cube in your system)... that's not to say that I've heard all kinds of hums either, you could just have a type that I haven't heard yet.

My official stance is: I dunno what to classify your problem as :shock:

Schrebowitz
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Post by Schrebowitz » Wed Dec 10, 2003 1:03 pm

This might sound silly but this actually can help, at least i know of occassions when cd players and amplifiers of hifi quality have produced a quiet buzz. A thing as simple as to reverse the polarities of the powerplug killed the noise, also are u using earthed or unearthed power? (plz correct me if i am using the wrong expression)

grandpa_boris
Posts: 255
Joined: Thu Jun 05, 2003 9:45 am
Location: CA

Re: backround noise from speakers

Post by grandpa_boris » Wed Dec 10, 2003 2:31 pm

AzN jonzOrz wrote: Right when i powered them up, i realized they have loud buzzing. I don't know if this is normal or because of some kind of interference. Anyone know if this is normal?
first of all, it is not normal. as you said yourself, this isn't a hiss of the amplified thermal noise. it's buzzing. every time i had ran into a loudspeaker buzzing in the past has been due to faulty grounding. the sound in this case is distinctly a 60Hz (50Hz for europeans?) tone and its harmonics. more recently i had discovered that when i use my cell phone too close to my computer speakers, it will induce significant buzzing.

AzN jonzOrz
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Joined: Tue Sep 02, 2003 4:04 pm

Post by AzN jonzOrz » Wed Dec 10, 2003 2:54 pm

I thought it was the 60Hz tone as well. I'm going to buy a "power filter"(don't know the term) but it should take away any improperly grounded problems right?...i'm not sure. Maybe my house just isn't properly grounded. I'm in the US so if that helps.

AzN jonzOrz
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Joined: Tue Sep 02, 2003 4:04 pm

Post by AzN jonzOrz » Wed Dec 10, 2003 2:55 pm

By the way, buying a new set isn't an option as i don't have any money and these speakers are a present.

grandpa_boris
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Location: CA

Post by grandpa_boris » Wed Dec 10, 2003 3:23 pm

AzN jonzOrz wrote:Maybe my house just isn't properly grounded.
that's entirely possible. i was unable to use a surge supressor or a UPS on my systems in my old house because the power wiring wasn't grounded. but it's also possible that you have an unshielded input on the speakers that is simply picking up the the induced 60Hz noise (although that shouldn't be loud, just a horribly irritating sine wave that is always there).

Cosine
Posts: 92
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Post by Cosine » Wed Dec 10, 2003 3:40 pm

CRT_Leech wrote:If your soundcard supports Digital S/PDIF output, buy a set of Digital speakers. I've been running digital speakers for over three years now and they are completely silent at any volume, if there is no input.

Good luck,
CRT_Leech
Really? I'm always annoyed by the general hum/buzz of speakers when not in use, tell me more about how the digitals are different.

Cosine

pld
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Joined: Wed Dec 10, 2003 4:21 pm

backround noise from speakers

Post by pld » Wed Dec 10, 2003 4:27 pm

I have two sets of monsoon NH500 speakers Three out of the four satellite speakers buzz to the extent that I have stopped using them

grandpa_boris
Posts: 255
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Location: CA

Post by grandpa_boris » Wed Dec 10, 2003 4:52 pm

Cosine wrote:Really? I'm always annoyed by the general hum/buzz of speakers when not in use, tell me more about how the digitals are different.
you aren't asking me :-), but in my experience digital connection to the speakers removes the noise component that comes from the thermal noise in the chipset on the sound card or the motherboard and doesn't pick up the EM-induced noise on the connector. the amplified speakers, in turn, don't amplify this noise and add it to their own thermal noise. however, with reasonable quality sound cards and with my aging ears, this was a minimal reduction in noise. i got a lot a lot more effect from switching from analog to digital link between the cdrom player and the sound card.

AzN jonzOrz
Posts: 46
Joined: Tue Sep 02, 2003 4:04 pm

Post by AzN jonzOrz » Wed Dec 10, 2003 8:40 pm

Is there a way to "fix" my grounding problem?

grandpa_boris
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Location: CA

Post by grandpa_boris » Wed Dec 10, 2003 10:19 pm

AzN jonzOrz wrote:Is there a way to "fix" my grounding problem?
before you try fixing anything, does this happen with any other set of speakers? like the dirt-cheap crappy ones that computer shops sell for "$0 after rebates". i have a strong suspicion that this is something very broken in your speakers, not in your house wiring. if i were you, i'd call the speaker manufacturer's support line and ask them.

AzN jonzOrz
Posts: 46
Joined: Tue Sep 02, 2003 4:04 pm

Post by AzN jonzOrz » Wed Dec 10, 2003 10:53 pm

funny thing....monsoon is not in the computer speaker business anymore so they stopped offering support. My other speakers that were not flat panel, did not exhibit this kind of behavior. Could it be that the flat panel speakers are amplifying the sound for some very odd reason?

Edit: i stress that the noise only comes from the flat-panel part of my speakers system. And these were new speakers :x

silvervarg
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Location: Sweden, Linkoping

Post by silvervarg » Thu Dec 11, 2003 4:43 am

Not really sure what things are called in English, so do correct me if I'm using the wrong words.

Do the power cable to the speakers use a ground (earth) wire?
Do you have power outlets with earth connection?

If the speakers power cable has ground wire and your outlets don't have ground there is a few things you can do.
1. Use a power split cable with ground connectors. Connect all your computer equipment to the same power splitter.
This will not attach any of your component to real ground, but they will at least have the same ground potential, and that might help.

2. Connect one ground point of the power splitter to real ground. E.g. you could attach a wire to a bare metal pipe, like a water pipe for the heater in your room.
This will actually give a real grounding to all components.

Not sure if anything out of this will really help your case, but it is good things to do anyway, and both things will be very quick and easy to do.

Rook
Friend of SPCR
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Location: Edmonton, Alberta, Canada

Post by Rook » Thu Dec 11, 2003 5:41 am

This may not be the case here, but one thing to keep in mind is that CPUIdle (if you're running it) causes speakers to buzz on some systems. This problem is noted in the CPUIdle FAQ.

AzN jonzOrz
Posts: 46
Joined: Tue Sep 02, 2003 4:04 pm

Post by AzN jonzOrz » Thu Dec 11, 2003 5:02 pm

No the speaker psu does not have a three-prong plug. they are plugged into my powerstrip which does have a grounding prong.

Rook: My speakers make this noise even without any input.

silvervarg
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Location: Sweden, Linkoping

Post by silvervarg » Fri Dec 12, 2003 1:38 am

I think t could be possible to add a simple filter to screen out the low frequency compleatly (hi-pass filter). That would kill all noice below say 70Hz, but will also effect noise slighly above, say up to 100Hz.
If it is possible to attach the filter so don't affect the subwoofer the noise quality should not suffer noticably.
The questions are what the cost and work would be and where the filter components can be hidden.

AzN jonzOrz
Posts: 46
Joined: Tue Sep 02, 2003 4:04 pm

Post by AzN jonzOrz » Fri Dec 12, 2003 6:34 pm

Thats exactly what i was thinking because my friend bought some for his computers and sound equipment. He got them at flee(sp?) markets. Now the question is, will i be as lucky in finding them as him. And how much will it set me back.

EDIT: you are talking about a filter connecting the AC power to the transformer right?

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