One sub that blends well with Maggies is Rel, they are definitely fast enough, in fact they are made to be matched. But difinitely look into the cat-issue when getting planar magnetics ! Mine survived for nearly 30 years, having 3 different cats in that period. Only one of them was tempted to try and scratch them when she was just a kitten. The other 2 just knew they were not allowed to come within 5ft. of my speakers .