Why does my 1394 audio sound bad during DV or HDV preview?
External sound devices connected to the computer by a 1394 cable are not recommended. You should instead use a PCI sound card, USB audio device or the on board audio built into most motherboards. In most cases, 1394 is not able to transfer DV or HDV footage while also feeding a 1394 audio device, causing crackling, popping and loss of audio playback. Note: PCI sound cards which double as 1394 cards, such as the SoundBlaster Audigy series, will function correctly.