Doc,
I have also heard that Sonar is not exactly the most cooperative program when it comes to sound drivers but I don't use it. I think the WDM drivers are the culprit, use ASIO instead.

My AC97 card doesn't seem to like other sound cards being around so it is deactivated in the BIOS.

I had managed to get the latency down to about 10-12ms in the SB Live for 48KHz/16 bits, using ASIO4ALL and then to about 8ms with the hacked KX drivers, if I remember well they are drivers made for Creative's own E-Mu line of cards that share the same processor as the Live and Audigy. Then I bought the Audiophile and the latency went down to maybe 5-6ms in 96KHz/24bits.

Also, the quality of the sound itself also changed, even not so good MP3's were playing with better clarity, they were sounding on the Audiophile like I got some new speakers. I could actually hear the difference.

Burkels,
please tell me more about your setup.

Well to start with: I recently bought a new system that I use for my music ONLY. It doesn't even have internet access :-) So it's a very clean P4/3 GHz system, running WinXP-Pro (every unwanted and not needed accessory removed), 1 Gb RAM, 250 GB HD, Audigy 4 Pro for sound, MIDI through a Steinberg Midex-3 and through USB, Club Dual videocard powering two 17" TFT's. For software I use Adobe Audition and Cubase SX. And that's pretty much all there is on the system.

Latency is not only caused by your soundcard or its driver. Other drivers, memory-eating DLL's that you don't need at all at that moment, drivers for games, joysticks, gamepads, video-accelerators, etc etc, they all want their part of the CPU's 'attention'. Which, of course, causes your system to slow down and cause unacceptable latency when you're recording.

So even though I know not everyone can "just" go out and buy a music-only PC, I still recommend that as the best solution when you're interested in making multi-track recordings on your PC.