The Successor to AC'97: Intel High Definition Audio

An anonymous reader writes "A few days back Intel announced the name to its previously dubbed 'Azalia' next-generation audio specification due out by midyear, under royalty-free license terms. The Intel High Definition Audio solution will have increased bandwidth that allows for 192 kHz, 32-bit, multi-channel audio and uses Dolby Pro Logic IIx technology 'which delivers the most natural, seamless and immersing 7.1 surround listening experience from any native 2-channel source'. The architecture is designed on the same cost-sensitive principles as AC'97 and will allow for improved audio usage and stability."

Comments

Finally

[AaronW]

I look forward to a decent standard for computer audio.

44.1Khz sampling and 16 bits are barely adequate depending on the music. When music has a large dynamic range from quiet pieces to loud pieces, 16 bits doesn't cut it. Also, all the filtering necessary for the 44.1Khz sampling rate also tends to screw up the sound. Before sampling at 44.1Khz you must filter out everything above 22050, and there's no such thing as a perfect brick wall filter. Filters screw up the phase and introduce all sorts of ripples the closer you get to the cutoff frequency. The higher frequency will also help improve the clocking. I listened to a high-end DAC connected to a good CD transport with 2 digital interfaces. One was the standard SP/DIF interface and the other had all the signals separated so the clock and data are never combined and hence no clock jitter. Digital is digital, right? I didn't expect to hear a difference, but I did. DACs do not like jitter. The other interface sounded more detailed. Of course this wasn't on a standard home stereo system either.

This will also remove a lot of the audio processing that currently occurs for 44.1KHz. I.E. virtually all CD players, etc. oversample and interpolate the signal to try and clean it up before filtering. You need to filter the output of the DACs too to get rid of harmonics introduced due to stair stepping and whatnot.