Thanks to everyone for their replies.
I have always taken ALSA for granted and have been content with it so I couldn't say whether I preferred ALSA to PulseAudio because I'd never tried the latter until now.
Recently I tried to help a new forum member to solve a problem with an Audigy2 - SB Audigy 4 in this - to date - unsolved topic
, and this prompted me to try and enable my CA0106 Soundblaster Model: SB0570. It had been lying unused in a drawer for several years and previous attempts to make it work had failed miserably, so much so that I once nearly threw it away in a fit of pique and thinking it must be defective. I also have a Creative Inspire A500, 5.1 surround sound speakers so this was a bit disappointing and I made do, first with onboard, and later with a Genius 5.1 PCI sound card. Although I once managed to get rather poor qualtity sound from the SB card through 2.1 speakers my Soundblaster fell, to coin an oxymoron, "deafeningly silent." So, having read the other post, I decided to install Wheezy to a vacant partition (with the 3.0.0-1-amd64 kernel) with the pci SB card inserted and onboard disabled in the BIOS. The Soundblaster sprang to life producing much better sound than I had ever got from the other devices but I have been unable, so far, to configure surround sound from all 5 speakers in addition to the woofer: at best I could get sound from only 3 or 4. So I decided to try this forum How-to: Pulseaudio
which has resulted in excellent 5.1 surround sound through all speakers. I found it was very easy to configure the card using PulseAudio and the results are...well...awesome
. I suppose the Audigy2 - SB Audigy 4 is even better.
I can also now confirm that this particular card works perfectly in Stable with the default kernel, but I'll post about that in another topic
To conclude, in answer to my own question, I gave a vote of thanks to PulseAudio because it solved the 5.1 speaker system issue although I'll have another go at configuring the .asoundrc file to get all speakers working properly with ALSA in Squeeze.