Missing Audio: Traveler & SP2

[frankjr90]

When I make live audio recordings on my laptop using Sony Vegas 7.0 and a MOTU Traveler (original model), I have discovered that occasionally and intermittently small segments of sound (milliseconds) are mysteriously missing from the recording. When this happens, the recording is incomplete and looks and sounds like a bad edit. The length of the recording is shorter than it should be; there is no gap of blank audio or drop-out, but it is as though the entire system was paused for a fraction of a second. This error is undetectable during the live recording, and can only be discovered afterwards. I make primarily speech recordings, and these gaps in the sine wave are not obvious to the eye, but can usually be heard (unless they happen between words). The timeline is continuous and has a consistent stream of audio input (no gaps).


These recording errors are easily discovered by syncing the audio from my laptop to the audio taken from a video of the same program.
I have had our IT personnel do thorough testing of my computer, and they have determined that the hardware on the laptop is not at fault.

I have done extensive tests with various buffer size settings with Vegas and the MOTU Traveler, and have decreased the occurrences but the problems continue sporadically.

I believe that the MOTU Traveler may be the cause, but I can't verify it.
When the buffer sizes are modified between 512 and 8192 I get no errors and have chosen 2048 to be my baseline. But every once in awhile an error pops up!!?!??

This has been going on for months, and I'm desperate for expert advice and help. I'd also be interested to know if anyone else has experienced this same phenomenon.

I would greatly appreciate any help.
Thank you!

Other bits of info…

XP Pro SP2 (ver 2002)
1.83GHz
987 MHz
2GB RAM

MOTU Traveler Settings
Driver: MOTU FireWire Audio v 3.40
Enable Multi Channel Wave Synchronization


SONY Vegas settings
48KHz
24 Bit

Computer Settings
Screen Saver: off
Hard Drive: defragmented with over 50 GB free space
Anti-Virus Program: none
Autostart Programs: all unnecessary programs are off

[Mark S]

are you using an external hard drive to record to?

If you're using only one hard drive you might try to see if there is a read or write cache or buffer setting somewhere in Vegas.

I'd first suggest trying an external usb drive to record to if you haven't.

Working here off the guess that something is getting lost in all the data stream from all the read/writes going to the same drive

I'd also look into you laptop bios to see if there are pci latency timer settings and lower it for the video card.

Network and wireless turned off in bios? While recording they should be,...

I have basically the same setup and have had no trouble doing an 8 channel recording using my 896hd, but I use an external drive.