HTPC for best sounding audio

HTPC's HDMI usually supports up to 8ch 24bit 192kHz LPCM audio (as well as bitstreaming all DVD/HD DVD/BD compressed audio formats). What's the source of your audio? If a proper audio decoder is installed (depending on the source), you will get lossless audio.

For example, rip DVD-Audio in FLAC (lossless audio format) by DVD Audio Extractor. Playing back FLAC should be easy with proper source filter/decoder/WASAPI exclusive mode in XBMC/MP.

You can`t use DS filters in XBMC even if you wanted to . Yes, FLAC playback is supported in XBMC just fine, so are FLAC tags.

Depending on the quality level of the rest of your audio system, you may find going to an external audio device for your HTPC may also improve your listening level. Going external removes the audio from the RF noisy environment in the PC and also gives you an opportunity to reduce jitter to really low levels.

I use a USB to SPDIF external box called a Firestone Audio Bravo Transport.

http://www.firestone-audio.eu/shop/p...sted/bravo.php

Jitter suppression is provided by the onboard Wolfson WM8804 chip and brings jitter down to 50ps.

RF noise on a digital connection (PCM via HDMI) ? That`s a new one

for music most of the time flac is your best bet, sometimes "friends" let you borrow their dts music, in order to play that you can setup mpc-hc. I have XBMC launching MPC-HC on DTS files.

I find the HD audio and video from the HDMI output of my AMD 6850 is gorgeous, it is as good as my stand alone BD player.

HDMI Audio output from a new Intel, AMD are all lossless - supporting Lossless LPCM, DTS-HD (Master Audio), Dolby TrueHD. This is what you want.
products include:
Intel 5 and 6 series
AMD 5000, 6000 series, APUs

I don't know where NVIDIA is at in their Audio support. I know they were behind, but I'm imagining they have caught up by now. So if you are going for something with NVIDIA, double check.

LPCM is an uncompressed audio format, so always lossless. NVIDIA's first 24bit 192Hz 8 channel LPCM solution was GeForce 8200 mGPU in 2008. The current GeForce 400/500 Series dGPU (except for GF100/GF110) support TrueHD/DTS-HD.