Lately I've sold every cabinet I owned,except the 4560's. I've always liked waht they can do. If you are using them for home listening, instead of a sub you could try attenuating the midrange, or boosting the LF. If you start looking for subs to keep up, you are looking at some large or expensive solutions, when you consider the 103db sensitivity of the 4560. Or use some lesser subs and just don't turn up the 4560's.