Digital Crackling Recording and Playback

Basically here's my issue:

I have been using my Intel iMac with OSX Snow Leopard 10.6.8 for about a year and a half now with Pro Tools 9HD and my trusty Line 6 Toneport Ux8. Everything has always been recording fine until recently I decided to get an external HD (CalDigit 2TB AV Drive FW800). Since then I've cleared my Mac's internal HD and put it all on the CalDigit, it was mainly Pro Tools sessions.
Upon my first attempt to record straight onto the hard drive, I armed all the tracks etc, clicked play and then had to wait for about 20 seconds until the thing actually started to record. I had a band coming to record that day so for times sake I just switched back to the internal HD to record for now - fixed the recording delay problem, however now I start to get a SUPER annoying digital crackling when recording and playing back audio... This happened on the first track being laid down with no plug-ins and sometimes I even get that CPU Overload message coming up.

I'm really not working the mac this hard as before the CalDigit I had sessions with 70 tracks with loadsa plugins running fine!

I've checked all drivers, cleaned both the drives.

Im Stuck!

Please Help! Thanks

Try lowering your Bit rate.This to happened to me not long ago..I use Adobe Audition, and started noticing a crackling sound out of the blue, Lowered my bit rate and that took care of the problem.

Also try raising the audio buffer in Pro Tools.

They delay might have been caused by the external drive spooling up for the record though 20 seconds seems excessively long - usually it's only 4 or 5 seconds tops. I'm assuming you didn't add a count off for that particular recording session.

Ah Okay I dont remember these settings ever being changed to cause these problems but perhaps they'll need to be to accommodate the hard drive.

Anyway I'll try these and let you guys know how I get on.

Thanks for the quick replies by the way!

Tried both of these suggestions. Neither have helped. I'm getting really quite ticked off really because it's ruining any recording time I have.

Any other suggestions?

Thanks guys

I'm not really sure what it could be. Something with that hard drive or the file transfer screwed something up. I would contact Avid and get help from from them.

Avid Support Page

Make sure the settings of your external drive meet Avid's standards. They're really picky. I had that issue initially with my Lacie drive and once I changed the settings in Disk Utility, I was up and running flawlessly.

One other point, set up a separate admin just for Pro Tools on your mac. Pro Tools like to run in it's own little world LOL!

Feel free to message me if you have any other questions. Hope this helps you!