Brahms Quintet for Clarinet and Strings, op. 115.

The deep tone of German school clarinet might be also from the Albert System of clarinet used. It contains less holes; therefore more wood for resonance instead of keys. The mouthpieces are also different, the reed is longer.

Can't go wrong with the superb performance by clarinetist Karl Leister and the Leipzig String Quartet on the MD & G label.

+1 for Thea King and the Gabrieli, I love the way King is one of the gang instead of turning it into a mini-concerto, as usual the Hyperion sound is good as well .

There's a good video on youtube (decent quality audio/video) of David Shifrin with the Guarneri Quartet playing this piece in 2009.

If you're interested:
https://www.youtube.com/watch?v=gtN1scGYJKA

Excellent exchange of information in this thread. Thank you all.