After.. Waveburner? music buzz/distorts.

Question

Scenario: I am mixing a project in Logic 9 using new Alesis monitors with USB connector. I burnt out multiple mixes using Waveburner. In last instance, I burnt out cd, went to car to listen to it, then came back to Logic to touch up the mix. When I press play, music coming out of monitors now has noise buzz to it. I thought files might be corrupted, so went to itunes and played someone else's music and it too was buzzing.
I unplugged USB and plugged in headphones and my music files are not the ones with the buzz. They sounds great! It's only when I plug in the USB cable and listen through monitors. Soo.. I figured I bought crap monitors.
HERE'S THE THING.. I went over to friends house last night to do some mixing through his monitors. Plugged .25inch cables from his monitors to a small mixer, then to my computer using the mixer's USB output. His speakers worked great - burnt out a mix in Waveburner then listened to cd in his stereo. Went back to logic to touch up the mix and TRACKS NOW HAVE A BUZZ THOUGH HIS MONITORS!! We had to end the session early because.. like my monitors, once the buzz starts it doesn't go away. No matter how many times you restart the programs and computer.
Sorry to make this post so long.. but am I missing something?? It's driving me nuts to deal with this.
So far these are the conclusions I've come up with:
1. It's not my monitors (i think..) because it did the same with his monitors. But to make sure, we plugged in his monitor's .25 cables to his board and it sounded great. Only when plugged into my computer through a USB connect will they buzz.
2. It's not the tracks because they sound fine coming out of internal computer speakers and headphones.
3. I'm suspicious of Waveburner because if I import an audio file and play it through internal speakers, it will play and sound good. BUT when I plug in USB monitors and switch Waveburner audio preferences to USB Output, I'll press play and the marker will disappear and no audio will come out. Could it be that the signal somewhere is wrong somewhere and therefore giving me buzz when I use USB??
Anyways.. I'm hoping someone knows what I'm talking about and can help me figure this out. In the meantime.. back to mixing with headphones!
thanks

Answer 1

Hi, fane_j--
What MBP are you talking about?
Well, System Profiler puts it this way:
Model Name:
MacBook Pro
Model Identifier:
MacBookPro5,5
Processor Name:
Intel Core 2 Duo
Processor Speed:
2.53 GHz
Number Of Processors:
1
Total Number Of Cores:
2
L2 Cache:
3 MB
Memory:
4 GB
Bus Speed:
1.07 GHz
Boot ROM Version:
MBP55.00AC.B03
SMC Version (system):
1.47f2
It has just one 3.5mm + S/PDIF audio port, called "Combination Output" by System Profiler, used for either input or output, depending...
Intel High Definition Audio:
  Audio ID:    77
Headphone:
  Connection:    Combination Output
Speaker:
  Connection:    Internal
Line Input:
  Connection:    Combination Input
Internal Microphone:
  Connection:    Internal
S/PDIF Optical Digital Audio Output:
  Connection:    Combination Output
External Microphone / iPhone Headset:
  Connection:    Combination Output
Headphone:
  Connection:    Combination Output
Speaker:
  Connection:    Internal
Line Input:
  Connection:    Combination Input
Internal Microphone:
  Connection:    Internal
S/PDIF Optical Digital Audio Output:
  Connection:    Combination Output
External Microphone / iPhone Headset:
  Connection:    Combination Output
Does this answer your question?
--Gil