As SONAR < 8.5 hasn't been available for years, I assume you are talking about the SONAR X2-version??
If so, you'll get much more info on the X-forum above.
And being a silver member, you surely realise nobody can answer anything if you don't give any info about what you've done this far and what your system specs are. Basicly, AFAIK, setting up X2 for recording doesn't require any different actions from those of the previous versions of SONAR.