My setting, with a tip of the hat to Ibwdog, and running full range into a 215 cab is:
Woofer: Up full
Boost : Around noon
EQ : Everything noon, except a little bump for Low Mid
Countour : Off
Presence : 9 o'clock
5/4 Switch : so far I'm liking the 5 position with my 4 string Jazz
Volume : This is my " master " , and it's usually around 9 o'clock.
These settings seem to give a nice, clear sound, with a little thump down low, although using the "5 " switch really pistons those 15's ( JBL k140's ), so I have to watch the volume somewhat. My only gripe with this head is the highs. I just can't find a happy medium between clear and shrill , especially when popping. Lowering the treble seems like all or nothing, and I'm using the Presence more than anything to get a little sizzle, but I'm still not satisfied. I may try a foot pedal compressor to get the right amount of squish I like when popping. But, all in all, this is probably one of the most versatile, " all in one head " bass amps I've ever played. Wish it had a compressor though !