Audio distortion,crackles,pops

[matt0722]

The problem that is occurring seems weird to me and I can't figure it out. When I go to record on audio tracks (MIDI works fine) as soon as I punch in or shortly after a very obnoxious distortion or crackle comes in as well as a very long latency then when I end the recording, the problem persists on the monitor until I go into the playback engine and adjust various options in there. Then the monitor will sound fine until I go to record again and the problem resumes. This happens whether I'm running XLR cables in or direct input guitars. Here is an example of the sound.

http://www.mediafire.com/?aci6cnipm98bke3

To troubleshoot the problem I have done all sorts of things. I have adjusted just about every option I can find in the playback engine and hardware options. I have tried new cables and different microphones/instruments. I have tried my equipment in Cubase 5 and Garageband(both worked fine) I have removed every plug-in from the plug-in folder in case 1 was bad. I have also searched all over the forums for a similar probably and nothing has come up. I have probably tried a few other things that aren't coming to me right now. Any help would be great and let me know if I missed something. Thanks for any help in advance.

Computer model and processor speed: Macbook and 2ghz intel core 2 duo
OS: Mac OS x version 10.6.8
Pro Tools 9 version 9.0.5.
4gb of RAM
Attached directly to the computers USB ports I have my Zoom R24 interface and a 10-port USB hub, plugged into that I have a USB MIDI converter, my Ilok, my Alesis USB speakers, and occasionally a USB micro card reader and a 40 GB hard drive. I have unplugged all of this down to just the bare minimum to run pro tools and record (Zoom R24, and Ilok).
I also have an external monitor plugged in via a converter.
and 1 firewire disk drive and 1 firewire hard drive but like I said I have unplugged all of this and the problem persists so it is not in the connections.

[zedhed]

Your USB Hub might be the problem since you have so many USB peripherals there may not be sufficient power to be running them all correctly.

I know you said " I have unplugged all of this down to just the bare minimum to run pro tools and record (Zoom R24, and Ilok)" but did you try plugging just the Zoom & iLok straight into computer ports bypassing the hub altogether (nothing else plugged in) and test PT?

[matt0722]

Yes I have tried plugging straight into the computer and bypassing the hub. Same thing.

[zedhed]

Have you got any access to another Interface or PT system so that you can record without the Zoom? It's going to have to be a process of elimination where you can cut parts of your chain out until you find the problem.

I'm assuming you have latest zoom drivers and that they are compatible with PT9.

BTW, I had too many problems with 9.05 so went back to 9.03. I'm not suggesting that this is your problem but it may be worth a try.

[matt0722]

No, I do not have access to another interface but I may be able to work something out. I'll let you know if I can figure something out. In the meantime any other suggestions would be fantastic!

[rudyrhythmz]

Sound Like A Clock Problem Check to see if the sample rates Match up for the device your using

[matt0722]

The clock source seems to match up but it does not look like anything I have read/seen before. If you know how the setup should be for the Zoom R24 that would be solid so I can make sure I have it correct.

[matt0722]

Still need help sorting out this issue...

[bradch00]

Have you deselecting " Minimize Additional I/O Latency" in Setup -> Playback Engine, this is a known source of distortion in PT 9.0.5.

[matt0722]

@bradch00 yes, I have that deselected.