View Full Version : New iMac - Recording/Distortion Problems

Sep 16, 2006, 01:23 AM
Hi Everyone,

I'm new both to Macs and to computer-based recording. I bought a new Intel iMac 17" three months ago, and picked up a Mackie Onyx 400f and some mics to try my hand at recording. Garageband seemed to be taxing my iMac to its limits, so I upped the RAM to 1 GB and started using Tracktion 2, and everything went great for a couple weeks. But in the last two weeks latency started to become more noticable, and I began getting crackling/popping distortion on everything I record, even with low input levels (-40) and very simple, no effects recording setups (like adding bass to a click track). I've even heard the popping noise happen while I wasn't playing a note, just had the keyboard hooked up and the machine recording. When I shut down and restart the iMac, the problem seems to go away for a short time, and returns when I record for several minutes. In the middle of recording this evening the computer gave off a loud, distorted shriek and showed me a message I hadn't seen before:

"CoreAudio: Disk is too slow. (Record) (-10004)"

I'm recording at 44.1kHz, 24-bit. Problem's the same with both Tracktion and Garageband. As I'd mentioned this is all new to me, and I am at a bit of a loss. Any thoughts would be greatly appreciated.



Sep 16, 2006, 01:34 AM
How full is the internal hard disk? If it is very full it may not be able to find a place to write to the disk quickly enough.

If it is full, an external disk might be in order or deleting stuff on the internal.

If it isn't full, tell us.

Sep 16, 2006, 01:43 AM
Can you tell us if any 3rd party RAM was added. What else is connected to your awesome machine? What is the complete setup please?:D

Sep 16, 2006, 02:50 AM
1. record to an external firewire drive. recording to the drive that's running the OS and your DAW can easily overtax the drive.

2. digital spikes can be the result of two clocks running independently. if it's showing up in the recording, then that lends weight to it being a clocking problem. i'm not certain how it works w/ tracktion, but see if there's a way to sync the DAW clock to the onyx, and make sure the onyx is synced to itself.

Sep 16, 2006, 12:32 PM
Hi Guys---

I've got 124GB free on a 150GB drive. I added another 512MB of RAM which I purchased from DMS. My setup's pretty simple--I've got the Onyx hooked into the iMac via Firewire, and M-Audio monitors hooked into the Onyx. Other than that just the mouse, keyboard, and a Canon printer in the USB ports.

Zimv, I'm not sure I understand how to make sure the clocks are synced--in the Onyx Console program the clock source is set to internal, and in the Audio MIDI Setup on the iMac, the Onyx' clock source is set to Device. I can't find any clock settings in the Tracktion program itself.

Much thanks for these replies!


Sep 18, 2006, 12:37 PM
Zimv, I'm not sure I understand how to make sure the clocks are synced--in the Onyx Console program the clock source is set to internal
i reckon it should be set to sync to the onyx. that's how PTLE handles it, anyway. give it a try and see if the spikes go away.

btw -- how are you liking the onyx?

Sep 22, 2006, 12:19 AM
It's a funny thing....

I was exploring the Onyx Console software to see about clock settings, and I came across something I hadn't been aware of: if the Console is turned on, the Onyx sends a monitor signal directly to headphone/monitors. If Console is off, the signal goes into the computer, through the sequencer, back out to the Onyx, and THEN to the monitor mix, thus apparently using enough of my iMac's resources to leave it gasping for air. I turned the Console on and have been recording some stuff, and everything seems ok. D'oh! Live and learn, I guess. :rolleyes:

Zimv, to answer your question, I like the Onyx, it sounds good to me and it's been easy to use. (Basically I hooked it into the Mac's firewire port and it worked, end of setup.) But I don't really have anything to compare it to, since this is my first computer recording setup.

Thanks very much for all the helpful advice.


Sep 22, 2006, 08:54 AM
I like the Onyx, it sounds good to me
can we hear some sound samples?

Sep 28, 2006, 11:05 PM
Hmmm....What kind of samples would you be interested in? A full song, or just individual instruments?

For the past week things have been working great, and then all of a sudden this afternoon the digital static started showing up again, in every single track I record, regardless of levels. I can't imagine what could be different between the way I'm recording today and the way I recorded last night, when everything worked fine. I'm dumbfounded.

I'll look into an external hard drive, and see what I can afford. But it may be a while before I have decent samples for you...:rolleyes: