Audio interference - technical help needed

[TheYak]

Jeez, I'm normally the technical advisor at work and home so this just feels wrong.  However, since we've a number of audio gurus here and some knowledgeable about computer hardware, I thought I'd give 'er a go:

Within the past 48 hours, I've started receiving a noise over my headphones.  The noise repeats approximately every 10 seconds and comes in louder than all other audio.  Here are a few things I've done to try and resolve it:

- checked to see if it's white noise I didn't previously notice by lowering all volume controls.
- unplugged any unnecessary electronics in the area in case of interference.
- checked connections.  I've got an Audigy 2 ZS Platinum and normally use the front panel with decent Sennheiser full-ear-enclosing headphones.  I tried the speaker out connections on the card as well. 
- switched headphones (tried 2 other sets, in fact), the noise is the same but less clear
- muted each channel (i.e. CD Audio, MIDI, Wave), it appears to be on the Wave channel.
- lowered sample conversion in WinXP's audio panel (unlikely to fix, but WTH at this point, right?)
- checked for any changes in electronics or their connections that might've happened within the last couple days, don't come up with anything.

So, anyone have any ideas? Sorry for the crap recording (above link) but trying to record audio off of speakers with a mic is difficult, particularly trying to avoid feedback. The sound's basically the same but with no white noise and slightly lower in pitch.  Next thing to try is onboard sound (which I disabled before clean install for the Audigy) and I'm dreading that - it's crap.

[Afflict]

Well Yak ill go with the sound card is screwed or the headphones arnt making porper contact. But ill still go with the card... did you try another sound card.. you didnt list it so i dont think so. Try google.com you should get a decent webpage covering some of the hardware stuff. theres like a billion and 1 out there. 1 of them sud have an answer iam really tired know gota go crash and reboot.  Strange i think its a ghost in the machine call an exorcist.! bleh just kidding most common answer is alt ctrl del if that doesnt work just go format c: always a winner and number one technique in "microsoft for dummies" written by one of the evil mole men in sector 53 under the microsoft head qauters allocated somwhere in the nevada desert. right next to david copperfields lil ranch with his levitating llama.
(this could be an intresting idea for a game) it all started with the noise (dun dun DUN) SCREEECH!

... wake up Yak.
.... Matrix xp has you !!!!!

[RickJ]

Hi Yak,

I'm not sure how much I'll be but heare are some of my thoughts after listening to your noise.  Btw, was this a recording from speakers or from the headphones? 

Ok, I took a look using Audacity (screenie below).  The wave form magnitude is amplified to get a better view. 



The main frequency of the noise is 4 khz.  Calculate this by counting the number of cycles between 0.2195 seconds and 0.2200 seconds and dividing by the time difference.

f = (0.2200 - 0.02195) Cycles / 0.0005 Seconds

The gap between 0.2200 and 0.02205 seconds is evidence of a second (possibly more) frequecy present. 

What it probably isn't ...
Although possible. these are the least likely culprits, IMHO

• It's probably not comming from the power line related (i.e. 60 hz hum).
  
  
• It's not AM modulated so it's probably not from a radio station or anything like that.
  
  
• It's probably not a loose connection.  A loose connection would likely get you one or both of the above.
  
  What it may be ...
  Well, obviously you have to ask yourself what goes on at 4 khz.  Here are a couple of my guess to get you started.
  
  
• Power Supply - What frequecy do switching power supplies run at?  I always thought they were something like 15-30 khz but I am not sure?   I guess 4 khz is not entirely out of the question, especially if you have a malfunctioning power supply.
  
  
• Sound Card - Since the noise is in the middle of the audio range I suppose some of the sound card electroincs could have failed. 
  
  
• Software - You didn't say how fast your computer is but I suppose we can assume it runs at 200 Mhz or more, fast enough to have a 4 khz program loop.   
  
  I can't get out of my mind how the noise sounds, it has that white noise or random quality.    This kind of makes me think it's not a power supply.  I would not expect that to have such a random quality to it.   The same thing works against the sound card as well.  Although, DSP or other processors on the sound card are presummmably to run 4k program loops they are not entirely eliminated. 
  
  I just wonder if you don't have a resource contention problem with the sound card and some other device or software.  I sometimes disable AGS sound so I can listen to some MP3s while I write programs.  Ocassionally I do something that interferes with the MP3 player, sound card, or something and I get like a skipping record effect.  When I exit from whatever cased the problem the MP3 continues playing.  I wonder if the problem you are having is something similar?
  
  What has changed in the last 48 hrs?  Has your computer contracted a virus, spyware or something?  Have you installed any new software or hardware in that time?  Any other configuration changes?
  
  Sorry, I don't have more ideas or can't be more certain about anything.  I wish you luck in getting everything working again and hope I may have been of some help.
  
  Cheers
     
  

[TheYak]

Thank you very much.  You really attacked this one.  I figured it out but didn't post a follow-up since the thread was naturally working its way to obscurity.

Turned out not to be hardware-related (at least not directly).  It seemed to be a problem with the new Audigy 2 drivers which support DRM (Digital Rights Management).  Apparently, a license was downloaded upon opening an audio file. Not having been a part of the transaction, I was unaware of the download - damn Windows Media codec.  I'd previously tried uninstall/reinstall of drivers but it took a hardware removal, reboot, reinsertion for it to function properly.  Well, now if someone else has the same problem, maybe this'll help.

The weirdest thing about that noise is that it isn't a constant tone or static. I would expect either or those from a malfunction, bad connection, or interference. I think I mentioned it but the sound isn't constant. It lasts the recorded (via mic->headphones) duration then nothing for about 10 seconds.  Comparing a 4khz frequency (nice analysis by the way) to a 10 second delay makes for a very strange loop.  The sound also doesn't fade in or out in volume level but its volume is determined by Wave volume and hardware volume.

Thanks again for the input.

[Gregjazz]

Definitely the soundcard, IMO. I've tried Audigy 2's before, and there's always something wrong with them. With one of them I was getting bleed-through between "what you hear", "line in", etc. It was terrible. Right now I use one of the older Audigy cards, and it's great. Granted there were a few little things wrong, but the latest drivers fixed that.

Anyways, looks like I've found a new sound effect for my latest techno mix.

[RickJ]

What has changed in the last 48 hrs?  Has your computer contracted a virus, spyware or something?

It seemed to be a problem with the new Audigy 2 drivers which support DRM (Digital Rights Management).   Apparently, a license was downloaded upon opening an audio file. Not having been a part of the transaction, I was unaware of the download ...

Amounts to the same thing doesn't it.  Why don't you take the sound card back and get your money back?  Damm those MS lovers...