Duet pops and crackles problem
I'm a cinematographer and editor, total idiot to audio recording. I've just spent the last hour scouring the search function on pops, clicks, crackles with Apogee Duet. What I've come to understand is that sample rate and clock sync may be the problem. It doesn't seem to help with my problem.
My system specs are:
Mac Pro 8 core 2.8GHz, 32GB Ram
ATI 5770, Samsung 830 256GB Boot drive, 10.7.4 OSX
PCI cards: AJA Kona 3, Caldigit HDOne Raid PCI bus card
Apogee Duet Firewire interface
Shure SM58, AKG 220, EV N/D757a, a $20 pop filter from Sam Ash
4X4 Whisper Room booth inherited from a friend
All connected to a Monster Power 3500 rack-mount unit
Using GarageBand and Soundtrack Pro to record voice over
I bought the Duet two years ago and used it on OSX 10.5 for a voice over on a documentary that went well, since then it went into a shelve until recently. Now on OSX 10.7.4, installed newest available drivers and tried to do a voice over recording with terrible crackles and pops, they appear many times in the beginning of a word, sometimes in the middle of a word there would be crackles. I tried adjusting mic positions, turning off all unnecessary electronics to the bare minimum with only the Mac Pro and Duet. Went as far as removing the Kona 3 card and the Caldigit PCI-e card along with ram down to 16GB. Nothing seems to help "lessen" the crackles and pops let alone eliminate them. Switched to my Retina MBP running on battery with the Duet connected via Thunderbolt to FW adapter only to encounter the same problems with the 3 mics that I own.
I can only assume that I have a bad Duet from sitting in the shelve for two years. Can anyone give any word of advise? I can not find any settings within GarageBand or Soundtrack Pro to modify clock sync. The only thing I can do is set sample rate of 48K on both the Duet and the application. Within Soundtrack Pro there is an option under Synchronization for Sync To MIDI Clock, and Sync To MIDI Time Code. Checking or un-checking does not seem to do anything to me. The Duet side has no way of changing clock sync, it stays as Internal.
I'm just trying to learn of a way to find the root of the problem before going out to spend on more gear not knowing a clue about it. On a side note, connecting the mics to my broadcast HD camera produces excellent recordings, and it's what I've had to do in the mean time so it's not the microphones. I'm stumped. Any help is greatly appreciated and many thanks in advance.