How do you drive 12 Ohm speakers?

Lately I took home a pair of great looking and very impressive sounding Crystalvox (small russian brand) speakers. The speakers are big, use 3 8 inch woofers and have incredibly smooth highs. The problem is that they are rated 12 Ohm nominal and 8 Ohm minimal. With McIntosh the bass is rather loose. I put on my Mac 6900 on 8 Ohm and while I like the sound overall I can't help but wonder - what kind of amps do people usually use with 12 Ohm speakers?