Rumble noise

Question

Level 1

1 points

Rumble noise

My setup:

API 8200s (3) into an API 7800, connected to an Apogee Rosetta 800, which is connected to an 8 core intel Mac.

Software - Logic pro 9

My problem is this: I get a rumble coming from the left monitor that sounds like wind noise on a mic. It may be software-related but perhaps it's hardware related?

If I pan tape return 1 (left channel) over to the right, the rumble travels with it to the right - that proves it's not a duff monitor.

If I pull the main fader down to nothing the problem stays - that I don't understand.

If I hit the AFL button on the left channels the rumble disappears.

If I quit Logic, the problem goes away.

Whenever I play music from the iTunes application, I don't get this rumble, which makes me wonder if the Logic side of things is the culprit.

Any help with this would be so gratefully received.

Posted on Oct 5, 2011 2:22 AM

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Answer 1

Pancenter

Level 6

14,644 points

Oct 5, 2011 9:26 AM in response to jrm1

Just a couple of questions...

Does the sound appear on all Logic projects or is it something that's happening with your "Default" project?

If you open Logic, close any open project and load a blank template, is the sound still there?

Also, you mention the sound doesn't manifest when playing music in iTunes.

Are you say that all of the Mac's audio output: Audio/MIDI Setup - Audio Devices / Default Output & System Output are set to use the Rosetta as output?

How do you have the Inputs configured in Audio/MIDI Setup.

You aren't using any kind of Aggregate device I hope?

Personally, I never route any of the the Mac's System or Default outputs through my RME setup, only Logic has access to the high end hardware.

I'm trying to figure out how/why you're only getting the "rumble" when using Logic.

Also, I'm a little familiar with the API stuff, used it for a few days in another studio but it's been a while.

The sound you describe reminds me of a few of things.. 1. a solid state component going bad. 2. A digital clock problem.. but that would affect both channels. 3. A software plugin EQ or Effect on an extreme setting.

pancenter-

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Answer 2

jrm1 Author

Level 1

1 points

Oct 5, 2011 12:41 PM in response to Pancenter

Thanks for helping out Pancenter.

It now turns out that I have a distortion on the right channel of my mix bus. Any right channel in a channel strip pair will sound distorted if fed by audio. If I pan that right pot to the left, it goes away.

If I solo/AFL the strip it also goes away. That must surely point to the right hand side of the mix bus.

Initially I wondered if it was my Apogee Rosetta, but then if the sound is fine at all coming out of the API, then it must be fine going into it, surely.

Sound coming from iTunes (not just Logic) causes the same distorion, so it can't be Logic's fault.

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Answer 3

Pancenter

Level 6

14,644 points

Oct 5, 2011 1:31 PM in response to jrm1

jrm1 wrote:

Thanks for helping out Pancenter.

It now turns out that I have a distortion on the right channel of my mix bus. Any right channel in a channel strip pair will sound distorted if fed by audio. If I pan that right pot to the left, it goes away.

If I solo/AFL the strip it also goes away. That must surely point to the right hand side of the mix bus.

Initially I wondered if it was my Apogee Rosetta, but then if the sound is fine at all coming out of the API, then it must be fine going into it, surely.

Sound coming from iTunes (not just Logic) causes the same distorion, so it can't be Logic's fault.

First a rumble on the left channel... then distortion on the right? Your problem is evolving.

I don't know.. being a hardware guy I would shut the machine down, reseat the Rosetta, un-plug and re-plug all cables and remove that possibility.

That said, the rumble/wind noise you first heard can be an internal component going bad, that's one of the telltale signs of an IC going belly up.

pancenter-

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