I recently purchased a high-end PC from Boxx Technology that includes a dual-core dual-processor Opteron, nVidia 4500, six internal drives (one raptor, one large data, and a four-drive raid 0), and a X-Fi Extreme audio card. Everything seemed to be working fine (for an $8,000 PC one would hope so), except I had problems with the audio when playing XL H1 video. After a couple weeks of hair pulling, I think I'm getting closer to the problem. This afternoon I was reading the Creative SB forum, and apparently there are some major problems with the X-Fi cards. Many users have reported pops, cracks, noise, etc.

I mention this here because I know other members of this forum reported problems with their audio when playing XL H1 clips. Since the problem is related to the CPU performance, you may only notice the problem when playing HD clips. If you have a X-Fi card, that may be the problem. To resolve the problem, I removed the X-Fi card, used the audio on the mother board, and reduced the audio acceleration to the minimum required for synching.

Best,
Christopher

Problem - Playback of Canon XL H1 m2t files on Soundblaster X-Fi ExtremeMusic card has excessive popping and hissing. In some cases the popping and hissing is so loud that the audio is not recognizable.

After continued experimentation, I finally found the source of this problem and a solution that seems to work. The Soundblaster X-Fi card is not compaitible with the SiI 3114 RAID controller. One significant clue was that an m2t file moved to a non-RAID drive played back just fine. Other experiments showed that increased RAID activity also increased the popping and hissing.

As for a solution, go to the Audio Console in the Control Panel, select the Bit-Matched tab, and select the "Enable Bit-Matched Playback" check box. After running a few tests, that seems to have resolved the problem.

Best,
Christopher