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benk · Feb 11, 2008, 08:30 PM

Hi guys, I have a macbook (core two duo) that I want to do some voice recording on. I have a USB mic. My problem is that the USB ports seem to have a lot of internal noise. There's a constant high pitch noise (not too loud but very annoying) that's coming from my usb interface, it makes it basically impossible to listen to any of the audio that I record. I know it's not my mic because I've tested it on my pc and it sounds fine. I also know that it's not just my macbook, I have a friend with the exact same model and the noise is on his macbook as well. Anybody else notice this? I've recorded it using both garageband and audio hijack pro. Using audio hijack pro, I set the mic's input volume to mute but it still records this high pitch noise.

It's quite disappointing for me since it appears I'll have to go back to my pc (unless I can get it fixed).

ibook_steve · Feb 12, 2008, 10:10 AM

With a USB mic? Very strange. I don't have an answer for you other than to try some other software and see if you can still reproduce it. If so, it might be time to visit an Apple store. But the fact that your friend has the same problem is disturbing.

Steve

Andhee · Feb 12, 2008, 10:15 AM

Only yesterday I was getting the same high pitched noise I think you're on about, but it stopped every time I scrolled down a page in safari. I have the 2.16GHz model.

benk · Feb 12, 2008, 06:53 PM

Hrm, I have a 2.16GHz model as well. I'll have try and find some more mics to try out. I'm using a Beyerdynamic MMX1 headset.

analogika · Feb 12, 2008, 07:09 PM

can you upload a recording of this to webspace somewhere and link to it, so we can give it a listen?

Andhee is talking about audible noise generated by the MacBook when certain tasks are performed. It probably has absolutely NOTHING to do with the problem you're talking about.

Andhee · Feb 13, 2008, 08:28 AM

my bad.

why don't you just use the internal microphone? I use it all the the time for skype conversations.

benk · Feb 14, 2008, 12:18 PM

Here's a link so that you can hear what the buzzing sounds like: http://www.thewatt.com/buzz.mp3 (it's 10 seconds).

It sounds faint but it's enough to drive you mad.

analogika · Feb 14, 2008, 02:54 PM

That's at -60 dB!

I had to normalize the track to hear anything; it's way beneath the noise floor in my studio... I couldn't hear ANYTHING above the hissing from the mixer/EQ, and the fan of my MacBook playing back your file at normal working volume...

From what it sounds like, the mic preamp's power supply is bleeding into the audio signal.

Which is to be expected from a cheap mic pre-amp. -60dB is actually fairly decent for consumer stuff.

benk · Feb 14, 2008, 03:16 PM

From what it sounds like, the mic preamp's power supply is bleeding into the audio signal.

Thanks for your help.

Through speakers you can't hear it but through headphones it'll give you a major headache.

Do you think it might help if I tried an externally powered USB hub or is it something that's pretty much unavoidable?

analogika · Feb 14, 2008, 03:37 PM

Just to clarify: The noise we're talking about is this:

http://homepage.mac.com/spheric/buzz.mp3

If that's it, you *could* try an external USB hub, but I doubt there's much you can do short of switching to a different solution entirely.

Edit: I'm just listening to björk's Homogenic album, and when I was testing that link, it fit the music quite nicely. I'm not sure I see your problem.