Kclone,
To repeat and restate:
If you put a crossover unit ahead of the main speakers it will reduce the burden on the main speakers' woofers by attenuating the bass signal they receive.
If you put an (active) crossover unit ahead of the amp feeding the main speakers, it will reduce the burden on both the main amp and the main speakers.
If you use no crossover on the main speakers - there will be no reduction in the work they do at low frequencies.
Subs can be wired in any of these ways, so the direct answer to your question is:
"It depends upon how you choose to wire the subs".
Marty
FWIW, I personally use an active x-over ahead of the main amp. Not only does this minimize the "work" of the main amp and the main speakers' woofers, it allows me to use digital room correction for the bass signal that is sent to the subwoofers. IMHO, this is a great solution. Other posters to these threads sometimes prefer a different approach. Different strokes....
To repeat and restate:
If you put a crossover unit ahead of the main speakers it will reduce the burden on the main speakers' woofers by attenuating the bass signal they receive.
If you put an (active) crossover unit ahead of the amp feeding the main speakers, it will reduce the burden on both the main amp and the main speakers.
If you use no crossover on the main speakers - there will be no reduction in the work they do at low frequencies.
Subs can be wired in any of these ways, so the direct answer to your question is:
"It depends upon how you choose to wire the subs".
Marty
FWIW, I personally use an active x-over ahead of the main amp. Not only does this minimize the "work" of the main amp and the main speakers' woofers, it allows me to use digital room correction for the bass signal that is sent to the subwoofers. IMHO, this is a great solution. Other posters to these threads sometimes prefer a different approach. Different strokes....