Subwoofer insight.

Darn good idea.

Your existing speakers may sound great, however they are bass limited, and inefficient as you know.

1. a stereo pair of self powered subs is a very good idea, don't over do it. two, located near the mains, so the low bass and the overtones from those notes are directional.

2. removing the need for your existing amp to handle the bass is going to allow it to do a better job with your inefficient mains.

3. easy independent volume control/balance with the mains is nice, if buying new, remote vol of sub would be very nice. 

using different speaker taps directly to mains and directly to subs denies a fundamental advantage of self-powered subs. the need for bass comes from the source, the main amp will still be trying to make/send all bass, the main speakers will still be trying to make all bass.

you want to remove low bass signals going to both the main amp and main speakers, especially inefficient and range limited mains, like yours. then they both can do a better job.

preamp out to crossover, or preamp to sub with adjustable crossover, self powered subs,

then signal less low bass back to main amp or integrated amp line in. main amp now doesn’t need to deal with low bass signals. low bass signals no longer seen by inefficient main speakers, those speakers no longer ’try’ to make low bass.

ideally easy ability to adjust sub’s crossover and adjust subs volume. this has to be done while they are in their intended location, again, bass is not always mono, so I advocate a pair of front firing subs near the mains. if hard to access controls, and heavy, put them on low rolling ..., pull out, adjust, slide back in place, listen.

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