I have a mixer desk (Alesis Multimix8 USB 1.0) which I want to use as the input to Soanr X2 tracks.
 
I have installed the ASIO$ALL driver, and can see the input in Sonar X2 by the movement in the levels bars.  However I cannot hear anything through the computer speakers. I am running Windows 7 Home 32-bit quad
core with a pre-installed Realtek sound card.
 
I have tried changing the Preferences in Sonar X2, but it would seem I cannot there change the output to the speakers - so I can hear what is recording - whilst keeping the input as ASIO though the USB.
 
Any ideas?

Quickly b4 work... I am also using an old MultiMix 8 on Win 7-32. I first tried using USB: the native Windows drivers only gave me 16 / 44. Also tried ASIO4All. After extreme searching, I uncovered some old Alesis drivers which gave me 24 / 48. I used for awhile but *may* have caused random lockups. I now use MM 8 as just a mixer. Control Room Out goes to my Tascam monitors, Main Out to 1 & 2 of my trusty Echo Layla 24. 
 
BTW to old friends: rebuilding after the desolation... this is core of Phoenix MicroStudio.
 
You can use USB... depending on your driver. If you can separate the USB audio feed from the Control Room feed, you should be able to hear both. Try: 3 buttons lower right above 2 master volumes, set (l to r) out, in , in. Lemme know but I can't reply 'till tonight! Happy recording!

Thanks for this, but it doesn't seem to address my problem.
 
I can Line In the Main Output from the mixer desk into the soundcard Line In - in the same way I did with the old Multimix6FX, and hear it through the soundcard speakers.
 
However now having USB output from the mixer desk would have thought that I could use that as the input in Sonar X2 - whilst still hearing what I play through the computer speakers.
 
Is this possible?

If that will work at all, I believe that would have to be handled inside ASIO4ALL. The ASIO specification only permits one audio I/O device to be used at a time, SONAR, following the spec, will only allow a single audio device to be checked.

So does this therefore mean that USB input is redundant - as you cannot listen to what you are playing through the computer speakers?
 
Seems like a good case for avoiding mixers which have a USB out - what's the point?

The problem starts with the Realtek sound card and PC speakers not the USB based mixer. The PC sound card and speakers are fine for games but forcing them into serve as your DAW audio interface/playback solution has it's limitations.