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2011-12-03, 14:42
(This post was last modified: 2011-12-03, 14:44 by Nuwidol.)
Hi,
I tried searching Google & these forums but couldn't find anything. Apologies if there is a common fix.
I have a problem when watching anything on xbmc (actually I can just be in the menus to hear it too) that makes my sub produce a humming/buzzing noise. It doesn't happen any other time unless xbmc is open. Although it does seem to be linked to the master PC volume ie if the volume is lower in app & raised on my amp then I hear it louder. As soon as I exit the app it immediately cuts off & I've never heard it on anything else.
All the other speakers sound fine & don't have the problem.
Any ideas anyone?
Thanks.
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PatK
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2011-12-03, 16:05
(This post was last modified: 2011-12-03, 17:39 by PatK.)
Usually buzzing or humm.. is alternating signal slipping into the audio, a lot of older systems do it. This could be induced by the audio section of your PC or an external amplifier or harmonics in the cables. XBMC opens up the audio and you hear the noise.. close out XBMC and it closes the audio port no noise (no mystery here) The biggest offenders are cables inducing the humm (make sure the cables don't pass around AC cords) and bad grounds.
The easiest diagnosis is to try a different cable set, failing that; tie up the grounds (connect a single wire to the chassis of the PC and audio amp) or try another amplifier. Ensure that your connections are solid.. wiggle them with everything in place with the audio port open, you'll find the offender.. if it's a cable.
Just thought I'd mention something about the frequency of the buzz.... if it's an AC 60 cycle freq, it will sound like a neon sign, or ballast on a fluorescent tube on start up. If it doesn't have that ptich.. then the frequency is induced internally and the source is likely bad capacitors.
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Question: Do you have your HTPC connected to your TV via HDMI?
If so disconnect your Cable connection to the TV. Comcast feeds from my TV, through my HDMI cable, through my receiver to my sub.
Code:
GRANT ALL PRIVILEGES ON `xbmc_%`.* TO 'xbmc'@'%';
IF you have a mysql problem, find one of the 4 dozen threads already open.
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bobo1on1
cheapass Team-XBMC Developer
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It's the frequency of the mains voltage.
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DDDamian
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All good answers. I think Darkscout was tongue-in-cheek referring to the fact that many countries use 60hz AC mains lol.
As mentioned, your AVR probably has 3-prongs so a dedicated ground, whereas your sub likely has two prongs and no dedicated ground. This would mean your sub uses a floating circuit (no ground) and thus can be floating at something above 0V on the neutral.
Is the sub plug polarized (meaning one prong is wider and thus you can't reverse the plug)? Do NOT reverse it - see below:
A good thing to test if you have a meter or access to one is the neutral potential versus a true ground. Ideally there is no voltage difference between true ground and the neutral.
If there is more than a volt or two have an electrician properly ground your neutral - usually done to a copper water pipe with low resistence to true earth. It's a good safety practice regardless.
System: XBMC HTPC with HDMI WASAPI & AudioEngine - Denon AVR-3808CI - Denon DVD-5900 Universal Player - Denon DCM-27 CD-Changer
- Sony BDP-S580 Blu-Ray - X-Box 360 - Android tablet wireless remote - 7.1 Streem/Axiom/Velodyne Surround System
If I have been able to help feel free to add to my reputation +/- below - thanks!
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DDDamian
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One other note: check that the amplification or gain on your sub is not set to max - for many subs this high gain makes it very sensitive to stray currents. Usually try set it to halfway and then adjust the signal from your amp to your tastes.
System: XBMC HTPC with HDMI WASAPI & AudioEngine - Denon AVR-3808CI - Denon DVD-5900 Universal Player - Denon DCM-27 CD-Changer
- Sony BDP-S580 Blu-Ray - X-Box 360 - Android tablet wireless remote - 7.1 Streem/Axiom/Velodyne Surround System
If I have been able to help feel free to add to my reputation +/- below - thanks!