I’ve been trying to piece together some alternative STAC9200 drivers to replace the minimalist drivers provided by Dell and I’ve had some great success, and some major problems. Combined with some registry hacking, I think I’ve opened up a whole lot of possibilities for the lowly integrated sound card, and solved some long standing NBF user issues as well. For example, I’ve now got the following working:

• Dual outputs. I can now use the mic in as an output jack for speakers and the standard output as a jack for headphones. These are not independent jacks, that is you cannot send separate signals to each, but it is still a nice feature.
  
• Live input monitoring. Microphone and line-in can now be monitored in realtime with no latency without using ASIO drivers.
  
• Improved Mixer. The SigmaTel mixer combines playback and recording on a single panel for convenience and also allows you to ‘solo’ playback of each output device. Soloing is of limited value to most users but the option is there. It also shows numeric values for balance, yeah! Anyone who has accidently knocked a mixer balance to the right or left knows what a pain it is to get it re-centered on the windows mixer.
  
• “Internal Mic/Line-in” (aka “Stereo Mix”) as a recording input. This should make a lot of people happy as I have seen this requested many times.

I've also uncovered loads of SPDIF options, EQ options, Dolby features, SoundCard Power Management option, etc. There's quite a few features that Dell chose to hide from us.

I'm undecided whether to hack the new features into the Dell Drivers or add the missing Dell features (subwoofer mostly) into other drivers.

If anyone with some registry/INF/driver experience wants to help out, send me a PM. I'm tired now but I'll post some more details later...