I have a QSC CP8, and I have used it as a bass amp - at a practice only - along with a Q\Strip. A little EQ, and it sounded great.
There are lots of powered speaker options out there - Some of them are a bit voiced, or sound boxy. The QSC stuff is NICE. The CP speakers are a nice, cheaper, alternative to the K-series.
From an interview in Guitar World with Daryl Jones:
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What gear do you take out with the Stones?
"I use the Stones’ old 1970s Ampeg SVT head as well as going back and forth with some newer SVTs, and I always use two SVT cabs. In addition to that, I’ve been using QSC gear, some of their K.2 series - the 18” subwoofer, and the K.12.2 cabs.
"Also, I got onto a couple of the Jonas Hellborg preamps that he did for Warwick a number of years ago: I’ve been using that to run in front of the QSC gear."
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You don’t have to carry your own amp, I assume.
"Not with them, no. I still work with some people who don’t tour quite as luxuriously as the Stones do, so I’m not all the way out of that. I think my carrying gear days are mostly behind me, hopefully. On a lot of the smaller gigs I do, particularly the electric jazz gigs, I use the QSC stuff, a couple of K.8.2 cabs, the smaller speakers."