This thread is wandering a bit. The following is all IME/IMO etc.
I replied privately to a PM from
saying essentially the same things I and many others have said many times before. Basically:
- Room modes and SBIR usually dictate the smoothness of the bass response. Rarely is the best place for the mains in terms of imaging and such the best place for subs. That also drives the crossover point as well as what the mains can handle.
- Many "large" speakers still have high distortion producing large bass signals that can easily require 100~1000 times more power than midrange signals of the same loudness.
- It is usually better to use the power for the mains for the midbass up, offloading the system and speakers from deep bass instead of spending all the power in the wrong (physical) places.
- Crossovers do not instantaneously drop to 0 output above and below the crossover frequency. An octave away (below) the crossover the mains still have significant energy using typical AVR crossovers (I use steeper crossovers FWIWFM). That means you still need good bass reproduction in the mains, and equal loudness curves say there is still a fair amount of power going to the mains.
My Rythmik subs, in my room, provide more than an octave lower range than the Salon2's could deliver and MUCH more importantly provide much smoother bass response than I could get with the Salon2's positioned for the best stereo image and soundstage. With a 150 Hz crossover to the three 8" woofers (equivalent to about a 14" single cone), accurately reproducing that octave-plus from my 70 Hz crossover (Floyd Toole uses 80 Hz for his BTW) and up is critical, and having it integrate smoothly with both the subs and the higher-frequency drivers in the Salon2's is a vital part of the listening experience to me.
Frankly, what sold me on the Revels was not their deep bass (I have that handled quite well, thank you Brian and Rythmik!) but the smooth sound and transition among drivers from the lower midrange through the treble region. That is where many speakers fall down IME and Revel tends to shine. An instrumental or vocal run or song that spans an octave or two does not sound right through many speakers -- the timbre changes a little passing through the crossover regions, and little "ripples" are audible due to driver dispersion and such. As a musician and engineer little discontinuities like that drive me crazy. Yes, it's a short drive.
Having good subs well integrated with the mains means much better sound top to bottom with greater dynamics, greater frequency extension, lower distortion, and smoother frequency response for everything I want to hear, be it a small jazz combo, full symphony orchestra, or big action movie.
I think those comments apply to any good speaker setup. My speakers, including my subs, do that for me. May yours do it for you.
IME/IMO/FWIWFM/my 0.000001 cent (microcent) - Don