As an actual sub, no, I've never considered them. But I've looked at some of the little 6 inch subs for use as a front midbass driver and wondered how they'd do for bringing good bass to the front, maybe getting 100-150 watts and running from 60 or 65 HZ to 120-150. They may get you a little lower than you are right now if you run a couple but still won't be like putting in a sub.