@gdaddy1 wrote:
You will never find tight punchy bass by setting a crossover high near 80hz or higher and then having to lower the volume to remove boominess. Like stepping on the brakes trying to go faster. That's completely backwards and is NOT what a subwoofer was designed to do.
There are quite a few aspects to this. Depending on the nature of the bass response of both the main speakers and subs (from where they're positioned and further tweaked into place) there could be favorable scenarios for either solution, i.e.: a higher or lower subs-mains crossover point.
Making a general statement however that subs can't reproduce the range up to ~100Hz without sounding boomy is simply incorrect. Main speakers are usually positioned as a compromise taking both the range above and below the Schroeder frequency into consideration, whereas subs can be dialed in for low frequency reproduction exclusively with rather elaborate corrective measures via positioning, added bass sources, DSP and other.
Subs are also mostly actively configured, meaning direct amp-driver connection with dedicated amplification, much better woofer control to boot and a more efficient use of the power at one's disposal here without looking into a bunch of coils and what not of a passive filter.
There's also the problematic aspect of crossing over in the middle of the central bass area - that is, in the 40-60Hz range - and mixing what is likely two different bass signatures here. You could argue any crossover point is a potential issue, but to my ears - again, depending on several factors - the less intervening and most advantageous crossover point to subs typically sits somewhere between 80-120Hz handing over to the upper bass area. This way the mains are effectively relieved of LF (not least important when the woofer/mids of the mains cover the entire power region up to ~450-ish Hz, and possibly even higher), and the subs cover the most energy-rich area to which they can be favorably dialed in and are better suited to tackle. Subs sounding "boomy" are most likely badly implemented and/or badly designed/constructed or simply too small.
@tomic601 wrote:
No…. the physics are super clear…. trade efficiency aka trashy output for pistonic motion…
Efficiency and low frequency reproduction means large size, and that again means the large cones/effective air radiation area generated move very little for a given SPL. Nothing "trashy" about that, but rather accommodated physics where they actually matter, but are less convenient for the interior decor-minded. Moreover, I can assure you "pistonic behavior" of well-designed typically pro segment woofers with anything but wobbly cones/suspensions here is the least of your worries in a domestic environment vs. a smaller and much less efficient driver (usually in the least efficient, sealed box with maximum cone movement at the tune) that needs excessive excursion by comparison for similar SPL. Potential mechanical noise issues galore, thermal compression creeping in, elevated distortion - you name it.
+1