It's a question of where the crossover is.
My current Velodyne 12" servo self powered sub: full range l/r line out to Carver Amp. Speaker wires from Carver Amp to sub speaker wires in. Sub's crossover sends low bass only to it's internal amp. Then Sub speaker wires out to front l/r.
This method: the Carver Amp is amplifying all frequencies, no relief to it's job; however the primary l/r no longer try to make low bass, an advantage to them. Their highs/mids/upper bass are not in a cloud of self-imposed distorted low bass they had no business trying to handle.
IF you go to a crossover first, i.e. line out to self powered sub, then sub sends line out (no low bass included) to the Amp. Now the amp gets a break, it no longer has to make low bass, and it sends upper bass/mids/highs only to primary l/r. speakers also get the break of not trying to make low bass.
Reducing the low bass load from both the amp and the primary l/r is important when trying to keep amp power needs down, especially tube amps.
My current Velodyne 12" servo self powered sub: full range l/r line out to Carver Amp. Speaker wires from Carver Amp to sub speaker wires in. Sub's crossover sends low bass only to it's internal amp. Then Sub speaker wires out to front l/r.
This method: the Carver Amp is amplifying all frequencies, no relief to it's job; however the primary l/r no longer try to make low bass, an advantage to them. Their highs/mids/upper bass are not in a cloud of self-imposed distorted low bass they had no business trying to handle.
IF you go to a crossover first, i.e. line out to self powered sub, then sub sends line out (no low bass included) to the Amp. Now the amp gets a break, it no longer has to make low bass, and it sends upper bass/mids/highs only to primary l/r. speakers also get the break of not trying to make low bass.
Reducing the low bass load from both the amp and the primary l/r is important when trying to keep amp power needs down, especially tube amps.