Originally Posted by Schlotkins
Here's a question:
It appears that the sound support of Vista is very, very good. Let's say I wanted to output analog from the HTPC and just run it to amps. How do the DACs from good sound cards compare to something like a HK645 receiver?
From looking at the published specs for the HK AVR645, it's hard to tell what DACs they use. There's a lot more than just the DACs to consider. Within the audio path, there are a lot of components that will effect the signal quality. Most of the manufacturers of DACs that are used in pro and consumer electronics quote both dynamic range and total harmonic distortion figures. The HK AVR645 specs show the signal to noise ratio (SNR). Technically, the dynamic range is the SNR added to the devices headroom. However some of these manufactures use the same figure for both dynamic range and SNR. The HK AVR645 shows an overall SNR of 100dB and THD of 0.07%, while the typical good quality soundcard has a dynamic range of over 110dB. The latest DACs from TI/Burr Brown have a SNR of up to 132dB and THD of 0.0004%.
For a direct comparison of specs, you'll see the Creative Sound Blaster X-Fi Elite has a SNR of 116dB and THD of 0.0008%. Creative's E-MU product line has even higher specs for some of their pro-audio soundcards. A Lynx Two B shows a dynamic range and SNR of 117dB and THD of 0.0004%.
So as you can see, the performance specifications for a good soundcard can be a lot better than your typical AVR. However, you still have to consider the rest of the audio chain that's included in the signal path of the AVR.
Anyhow, you can do quite a bit better combining a good soundcard with other high quality components.