"A full range speaker should sound better with a smaller sub by virtue of its FR and the fact that it’s producing decent bass on its own already. Conversely, a small speaker should benefit from a bigger sub to cover a wider range."
It doesn’t work that way. Here’s the "old school" principles:
Smaller woofers/subs are TYPICALLY more limited in extreme low frequency output than larger woofers/subs. Since the presumption is that the OP has "full range" speakers already and wishes to further enhance the ultra-low bass output of his system, the larger woofer/sub SHOULD go lower, providing more ultra-low frequency enhancement, all things being equal.
Further, if the OPs "full range" speakers already have a strong mid/upper-low frequency output, adding a smaller (higher frequency output) woofer/sub will create boominess in that range (major overlap in the midbass). Worst of all worlds IME.
Conversely, a smaller woofer/sub should TYPICALLY be quicker and more tuneful in the mid/upper-low bass frequencies, thus easier to integrate with a "smaller" speaker, assuming that the latter’s low frequency output rolls off a significantly higher frequency than a "full range" speaker (minor mid/upper-low frequency overlap of the smaller speaker with the smaller sub’s higher output frequency). Ultra-low bass will not be enhanced as with the larger woofer/sub, but that is irrelevant if integration is poor.
Many potential exceptions to this are experienced in the real world as it depends heavily on the cabinet size/design of the sub, crossover adjustment flexibility, design (ported vs sealed), amplifier’s power/characteristics/ability to control the woofer, and placement. Also the newer concept of digital room equalization/correction built into the sub’s digital electronics (a’ la’ JL Audio and a few others) negates the "old school" rules to some extent, allowing a larger woofer/sub to integrate well even with smaller main speakers by tuning/contouring the sub’s output (increasing or reducing the output at certain frequencies based on system characteristics/room acoustics as measured by a microphone and processed by the sub’s digital circuitry).
Subs can also be used for entirely different purposes than "bass enhancement". I use two REL Stadium III sub’s fed via the high level inputs from my amp with the subs’ crossovers set to "out-of-phase" mode to cancel standing waves due to room bass nodes, actually reducing the perceived bass heard at my listening position, and to enhance the soundstage (by loading the room with sound pressure from the subs) as my main speakers need no low-bass enhancement, but actually the opposite in my room. Works quite well.
Dave
It doesn’t work that way. Here’s the "old school" principles:
Smaller woofers/subs are TYPICALLY more limited in extreme low frequency output than larger woofers/subs. Since the presumption is that the OP has "full range" speakers already and wishes to further enhance the ultra-low bass output of his system, the larger woofer/sub SHOULD go lower, providing more ultra-low frequency enhancement, all things being equal.
Further, if the OPs "full range" speakers already have a strong mid/upper-low frequency output, adding a smaller (higher frequency output) woofer/sub will create boominess in that range (major overlap in the midbass). Worst of all worlds IME.
Conversely, a smaller woofer/sub should TYPICALLY be quicker and more tuneful in the mid/upper-low bass frequencies, thus easier to integrate with a "smaller" speaker, assuming that the latter’s low frequency output rolls off a significantly higher frequency than a "full range" speaker (minor mid/upper-low frequency overlap of the smaller speaker with the smaller sub’s higher output frequency). Ultra-low bass will not be enhanced as with the larger woofer/sub, but that is irrelevant if integration is poor.
Many potential exceptions to this are experienced in the real world as it depends heavily on the cabinet size/design of the sub, crossover adjustment flexibility, design (ported vs sealed), amplifier’s power/characteristics/ability to control the woofer, and placement. Also the newer concept of digital room equalization/correction built into the sub’s digital electronics (a’ la’ JL Audio and a few others) negates the "old school" rules to some extent, allowing a larger woofer/sub to integrate well even with smaller main speakers by tuning/contouring the sub’s output (increasing or reducing the output at certain frequencies based on system characteristics/room acoustics as measured by a microphone and processed by the sub’s digital circuitry).
Subs can also be used for entirely different purposes than "bass enhancement". I use two REL Stadium III sub’s fed via the high level inputs from my amp with the subs’ crossovers set to "out-of-phase" mode to cancel standing waves due to room bass nodes, actually reducing the perceived bass heard at my listening position, and to enhance the soundstage (by loading the room with sound pressure from the subs) as my main speakers need no low-bass enhancement, but actually the opposite in my room. Works quite well.
Dave