mapman:"
If you have large full range speakers that go down to the mid 30s, if you add subs, you need larger ones that deliver output below that range in that there is little to gain to start with otherwise and you don’t want to merely add to the frequencies already there.
Hello mapman,
Your statement generally makes sense to me but only if the bass sound waves down to the mid 30s, that are being launched and reproduced by the pair of large full range and properly positioned stereo speakers, arrive intact at the listening position and are perceived as good quality bass.
It's well understood by acousticians, and has been proven scientifically, that deep bass frequency soundwaves behave very differently than midrange and treble frequencies behave in a given room due to physics. Full cycle, or complete cycle, deep bass soundwaves are omnidirectional in their radiation patterns. are very long (a 20 Hz full cycle soundwave is 56' long), are not localizable at frequencies below about 80 Hz and are therefore perceived by us as mono.
Full cycle, or complete cycle, midrange and treble sound waves, by comparison, are highly directional in their radiation patterns, are much shorter (a 1200 Hz midrange full cycle soundwave is under a foot long and a 20,000 Hz high treble full cycle soundwave is under an inch long), typically begin to be localizable at the higher bass frequency of about 80 Hz and the sound waves continue to become progressively shorter and more easily localizable as the frequencies increase beyond 80 Hz up to the generally cited upper audible limit of 20,000 Hz.
This localizable full cycle soundwave threshold bass frequency of about 80 Hz is also the common threshold at which stereo perception begins when discrete L+R mono channel signals exist and are reproduced through discrete and properly positioned L+R speakers.
My main point, finally presented, is that individuals typically position their pair of main speakers in the room, and in relation to their designated listening position/seat, in order to optimize their midrange and treble performance perception along with their stereo image perception. This results in individuals rarely, if ever, positioning their main speakers in their rooms, and in relation to their LP, in order to optimize their perceived bass performance. Individuals are unable to optimize the bass and the rest for the simple reason that the bass drivers on the full range speakers are permanently attached to the cabinet containing the other, equally permanently attached, midrange and treble drivers, and are therefore not capable of being independently positioned.
Obviously, this creates a Catch-22 like dilemma. I believe most individuals, formerly including myself, just position their main speakers to optimize their perception of the midrange, treble and stereo imaging at their LP and resign themselves to accepting whatever unoptimized bass performance they perceive at their LP. Since bass performance at the LP is also known to be highly dependent and influenced by physics and the room itself, the quality of the bass perceived there is also highly dependent on the physical relationship of the main speakers to the LP.
l strongly believe through personal experience, I know along with many others, that multiple independently positioned subs are a good solution to this dilemma. This solution is very effective whether it's achieved through the utilization of as few as a pair of subs or up to 4. used with a pair of larger full range or smaller limited low frequency range main speakers and can be configured to work well in virtually any size or shaped room.
I also don't dismiss the effectiveness of bass line arrays, open baffle, planar-magnetic or horn-loaded type subs, I just have a total lack of personal experience with utilizing these thus far.
I also wanted to state that I believe you agree, or at least already have a good understanding of, what I discussed above. I mainly posted for the benefit of other possibly less knowledgeable and experienced readers of this thread.
Tim
