If you are looking for musical truth, the Vandersteen approach of connecting the subwoofer with the assistance of a high pass filter directly to your amplifier's output, is a fine way to go. By feeding the subwoofers with the amplifier's signal mates the subs. sonic character to the sound of the rest of the system When set up properly, it should just sound like your speakers go lower with greater bass power. You don't "listen" to the subs. You listen to extended power response as if it's coming directly from your main speakers. I have two Vandersteen 2wq subs. which have adjustable level and "Q". So you can adjust the relative tautness of the subwoofer response. I recently traded in my Vandersteen 3A Signatures for Treo CTs. One of the first things I had to do to properly mate my two subwoofers with the Treos was to decrease their output level as the 3A's sensitivity was 89 db and the Treos 85 db. Just last evening I further tweaked that output level so the system is congruent.
If you are just looking for more bass, then there are much more affordable paths to follow. In the end, it depends on why you want the subs.
If you are just looking for more bass, then there are much more affordable paths to follow. In the end, it depends on why you want the subs.