I don't have a 2x10 currently - rather I have a 1x10 that sits on top of a 1x12. I usually turn off the horn on the 12 and turn down the tweeter on the 10 until I like what I hear. That seems to be not quite all the way off, but somewhere down from 12:00.
It also depends on the bass. When I'm playing a brighter bass, I turn the horn down more. If the high treble from the pickup is already a bit muted, I don't mind having a little tweeter mixed in. It basically matches whether I like the bass recorded direct too. My usual LPB-1 sounds good to my ears both direct to tape, and through a cabinet with a bit of tweeter turned on. Back when my main bass was a maple Ibanez with active Alembic electronics, I didn't like my direct sound much, nor did like playing through tweeters (I didn't have a cab with tweeters back then). I was forever asking FOH engineers to turn down the treble on the direct signal (or begging for a mic instead of a DI, but I rarely got one).