You can do a subject search in the catalog to find chamber music recordings. You can build your own strings of subject headings using the number and type of instruments desired. You can include as much or as little detail as you like. If you're getting too many results, try narrowing it down by including more detail and if you're not finding anything, use less.
String quartets (Violins (2), cello, double bass)
Quartets (Harpsichord, flute, violin, viola de gamba)
Wind quintets (Bassoon, clarinet, flute, horn, oboe)
Nonets (Accordion, piano, synthesizer, bassoon, clarinet, flute, saxophone, percussion)
Remember to limit your search to "Sound Recordings" if you're getting too many scores and parts in your results.