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sound interference

Posted: Mon Aug 10, 2009 7:39 am
by moriz
i've been getting these wierd interference with my razer barracuda headset. it's very hard to notice at first, but while its turned on, there's a tiny bit of white noise. what's even more strange, is that it will "rumble" for a lack of better words, when scrolling down on a webpage. also, certain elements of games and websites will also cause it to do it. it sounds like rapid fire, low volumn thunder. it can be hard to notice, but it's definitely there.

lastly, when i switch it off, it will function as a RADIO for about 2 seconds before the sound cut off.

so, there's something interfering with it, but i don't know what.

oh yeah, i'm using the adaptor that came with it, so it's taking up a USB port also.

Re: sound interference

Posted: Mon Aug 10, 2009 8:02 am
by Meadows
If computer interactions increase the noise, then it might come from either your audio device or the headset connection itself (something's not right with the motherboard then).

Re: sound interference

Posted: Mon Aug 10, 2009 8:33 am
by moriz
both my xonar dx and the onboard realtek had the interference, though the realtek was definitely stronger.

Re: sound interference

Posted: Mon Aug 10, 2009 9:09 am
by Meadows
moriz wrote:
both my xonar dx and the onboard realtek had the interference, though the realtek was definitely stronger.

I'd say you should try another pair of headphones, and then another motherboard (or somebody else's computer) using your Xonar.

Re: sound interference

Posted: Mon Aug 10, 2009 9:21 am
by moriz
i have a vague suspicion that it's the USB port. unfortunately, i don't have any other hardware that's in the same class as the barracuda.

i can try it on my laptop later on, but since it doesn't have the jacks for 5.1, i'm not sure how effective the test will be.

Re: sound interference

Posted: Mon Aug 10, 2009 9:26 am
by FireGryphon
It sounds like there's tons of radio frequency interference around your computer. Different headphones with a shielded wire might help. I'd also make sure that your setup isn't producing a ground loop.

Re: sound interference

Posted: Mon Aug 10, 2009 10:30 am
by moriz
how do i check if there's a ground loop?

Re: sound interference

Posted: Mon Aug 10, 2009 11:59 am
by sluggo
The "rumbling" that you hear is probably due to rapid, low-frequency modulation of the codec's 3.3V supply. When you scroll your display, every cell in the frame buffer's memory changes, creating current pulses on the 3.3V rail. The codec's filters are far from perfect, and the bouncing of the rail wiggles the codec's bias point enough to be audible in good headphones (it only takes a few millivolts).

The radio thing is not interference, it's just what happens anytime there's a wire and a diode in series with sensitive headhones. AM radio signals are everywhere, and if your particular location/orientation/product has the right diode in the right place while the amplifier is powering down, you'll hear the ball game or farm report or polka music (is there anything else on AM these days?) until the amplifier's supply caps run out of juice.

Neither problem is anything to worry about, but the first is pretty annoying. Unfortunately there's not a lot you can do about it. Some power supplies will be worse than others in this regard, but there's no spec for modulation in the ATX documents, so you get what you get. Some motherboard audio layouts will be better than others, but that's a roll of the dice as well. Short of a buying high-end audio card or taking optical out to an external amp, I don't know that there's an easy fix.

Re: sound interference

Posted: Mon Aug 10, 2009 1:00 pm
by moriz
is there any way to "shield" either the audio device or the headset, so i won't hear it?

Re: sound interference

Posted: Mon Aug 10, 2009 3:06 pm
by morphine
Just so we're clear: are you using it as a USB sound device, or with the 3x2 analog plugs?

Re: sound interference

Posted: Mon Aug 10, 2009 4:05 pm
by sluggo
moriz wrote:
is there any way to "shield" either the audio device or the headset, so i won't hear it?

If you're talking about the rumbling sound, no, not really. My assumption is the noise is being generated at the codec's output by a bouncy rail. Short of a PSU swap-fest or an add-on audio card, I can't recommend a solution. If it's any consolation, almost every PC audio setup has this problem to one degree or another.

If you're talking about the radio pickup, shielding may work, but you're going to have to figure out what to shield. Disconnect the speaker cable at the PC end and turn your speakers on/off and see if you can hear it. If so, then disconnect the cable and see if the noise goes away - if so, then try a better cable. If not, if the speakers are picking up AM radio with nothing connected, then you're pretty much screwed - there are ways to shield circuits but it requires some experience in soldering and metal forming. You might also consider returning them to the store for another unit - manufacturers are supposed to test their products for EMI susceptability and if yours is failing, you might be able to get a replacement.

Edit: Oops, forgot we were talking about a headset. Ignore most of the second paragraph.

Re: sound interference

Posted: Mon Aug 10, 2009 4:22 pm
by moriz
morphine wrote:
Just so we're clear: are you using it as a USB sound device, or with the 3x2 analog plugs?


the barracuda has a strange connector that looks like a DVI socket. as far as i can tell, only the corresponding razer barracuda sound card has it. obviously, it comes with an adapter that converts it into a standard analog connection with 4 jacks. it also needs a USB connection so that the headset get enough juice to operate. i have a vague suspicious that it's only for the fancy blue LEDs, but the headset won't function without that USB plug. as far as i know, the USB plug is only for the electricity, with no data being transferred in any direction.

@sluggo:

i have a xonar dx. however, it doesn't seem to be all that stable (occasionally crashes games, freezes in mp3 playback), and it also produces these rumbling sounds, though not as strongly. because of the stability issues, i was forced to take it out. maybe i should put it back in and see if i can find some better drivers for it.

Re: sound interference

Posted: Mon Aug 10, 2009 6:05 pm
by sluggo
moriz wrote:
@sluggo:

i have a xonar dx. however, it doesn't seem to be all that stable (occasionally crashes games, freezes in mp3 playback), and it also produces these rumbling sounds, though not as strongly. because of the stability issues, i was forced to take it out. maybe i should put it back in and see if i can find some better drivers for it.

If you have a spare PSU laying about, I'd give that a shot. It's unusual for a card like the Xonar to exhibit this problem unless the PSU is very (electrically) noisy. Swapping PSU's is not fun, but again, if you have one around, I'd try that first. It sounds like the one you're using now could be your weak link.

Re: sound interference

Posted: Mon Aug 10, 2009 6:31 pm
by moriz
i was using a molex-to-floppy adapter to power it. maybe that has something to do with it. i was too lazy to locate the floppy connector that came with the PSU.

do you think the fact that it uses a USB port to power it has anything to do with it?

Re: sound interference

Posted: Mon Aug 10, 2009 7:33 pm
by sluggo
moriz wrote:
i was using a molex-to-floppy adapter to power it. maybe that has something to do with it. i was too lazy to locate the floppy connector that came with the PSU.

If "it" means the Xonar card, no, the floppy adapter won't cause a problem.

Do you think the fact that it uses a USB port to power it has anything to do with it?

I had to look up the product on newegg, as the razer site has f all to say about their own product's specs. Looks like the headphones take multi-channel line levels and then have separate buffers/volume control in the headphone's handset, the handset being powered through USB. Does the current-limited USB power have anything to do with the noise? You can find out by connecting some powered speakers or regular passive headphones to your sound card - if the noise is gone, then the problem is with the headphones or the USB voltage regulator. If the noise is present with the speakers/headphones, look to the power supply.

Re: sound interference

Posted: Mon Aug 10, 2009 9:48 pm
by moriz
just tested with my old headphones, and there's no rumbling. or at least, none that i can hear. i guess that means it is either the USB connector, or the headset itself.

keep in mind though, the rumbling on my barracuda is very faint. for a long time, i thought i was hearing the vibrations from my mouse wheel. it wasn't until i did the "click wheel and drag" that i realized that the sound wasn't coming from the mouse wheel and travelling up my arm.

Re: sound interference

Posted: Tue Aug 11, 2009 11:45 am
by ludi
Check and make sure that all unused audio inputs are muted/disabled, both on the affected soundcard and any other sound devices installed on the system (e.g. motherboard integrated). Microphone inputs in particular, especially if the high-gain option is checkmarked, can be quite problematic for injecting system noise into the audio stream if they are enabled and disconnected.

Re: sound interference

Posted: Tue Aug 11, 2009 7:42 pm
by moriz
alright, just checked on my laptop with the headset, and there's no rumbling noise when scrolling. connected the xonar dx with my headset, and there's rumbling. that leaves power supply and/or the USB i guess.

Re: sound interference

Posted: Tue Aug 11, 2009 8:11 pm
by potatochobit
do you have a high powered graphic card?

Re: sound interference

Posted: Tue Aug 11, 2009 8:24 pm
by just brew it!
moriz wrote:
alright, just checked on my laptop with the headset, and there's no rumbling noise when scrolling. connected the xonar dx with my headset, and there's rumbling. that leaves power supply and/or the USB i guess.

Did you try what ludi suggested? Noise pickup from unused soundcard inputs is a very common cause of this sort of thing.

Re: sound interference

Posted: Tue Aug 11, 2009 8:26 pm
by TaBoVilla
I get this type of sounds all the time on my setups, laptops, desktops, no difference.

5v power rail being supplied via USB ports is also susceptible to RF interference, specially motor driven stuff, like fans and "usb powered" vacuum cleaners hehe. How this gets through the motherboard's USB hub, onto the audio plugs/audio riser boards/pci sound cards beats my understanding.

the only solution I've found has been to use an M-Audio external USB audio "card", more like a module really. With its own mic preamps, filters and stuff, I get practically no noise at all (windows or recording), well, maybe a bit, but I'm in no recording studio too, so..

Re: sound interference

Posted: Tue Aug 11, 2009 11:52 pm
by moriz
potatochobit wrote:
do you have a high powered graphic card?


yeah, i have a HD4890.

@just brew it!:

i have the headset setup in 5.1, with the mic also plugged in. i don't know how i can disable the last unused jack (xonar dx is 7.1, so i have one jack free), since there isn't really an option to do so.

my next step is to find an external USB hub, that can draw its own power through a wall socket... granted, i don't know if such thing exists, or is even affordable or not. this might turn out to be one very expensive non-solution if it doesn't work.

btw, i also get the rumbling whenever i record using Fraps. don't know if this would help diagnose this problem though.

Re: sound interference

Posted: Wed Aug 12, 2009 4:49 pm
by moriz
just an update:
i bought myself a USB hub that has an external power source, and it worked! the rumbling is completely gone. strangely enough, the headset sounds a lot fuller (and louder) than before. perhaps my motherboard simply wasn't delivering enough power through its USB slots to adequately power this thing.

there's still white noise when it is idling though, and it gets louder when i switch on the LCD lights. with the lights off, it is soft enough to be mostly ignorable.

thanks to all those who helped me. i appreciated it.