Am I missing something? This measurement differs wildly from your others of this design. Specifically, this measurement shows the expected massive out-of-band resonances one expects from a 4th order cabinet with a small box and big vent tuned low, and your others do not. It's even worse than intuitively expected if I'm honest - the port resonance is ~6dB louder than passband level at ~270Hz.
Based on your description of that product and the numbers on your website, I'm guessing pretty similar in price.
Also, I wouldn't say it's "much simpler," but rather that the complexity is elsewhere. Specifically, instead of a Bose style approach of minimum usable driver and maximum cabinet magic, that company designed a novel compound drive unit (not really needed to fit two beefy 6.5" drivers in an 8.6" deep cabinet, but I digress) and creative optimization of a limiter. In my view the big problem with that particular sub is the lack of physical drive-unit protection. I personally don't get it. It makes them more expensive end-to-end because exposed metal "cones" are easy to dent, and dented drivers kill residual values.
While that's correct as written, IMO the thought is incomplete. There is a way to get usefully high sound power at low frequencies without large subwoofers: multiple small ones! Subs largely sum coherently below the modal region. For example, here is a measurement (Geddes & Blind "sound power" method spatial average) of two very small subwoofers placed in the "front corners" of a 17' x 14' "room" within an open concept space (roughly 50' x 18' x 8') , left, right, and L+R together (measured, not calculated) at a roughly 10' listening distance. No dedicated acoustic treatments in the room, but typical American drywall-on-wood-studs construction. Note that the modeled F3 of these subs is about 60Hz. There is no EQ applied.
View attachment 283611
Note that there's little rhyme or reason to the sum above 45 Hz or so, but below that they sum fairly coherently. I can't recall an in-room measurement I've taken where that was not the case. The precise corner frequency moved up or down, but the general behavior was the same. So if each one of these can yield 88dB at 20Hz (modeled SPL at 20Hz at xmax is 92dB, and I think 4dB compression at full tilt is plausible given the 3" voicecoil and decent thermal management) that's still 100dB output at 20Hz anechoic. Not super-sub levels to be sure, but we're talking about under 1 cubic foot of
total cabinet volumes and a total floor footprint of well under 2 square feet (each 15" wide x 4.5" deep). Data-bass is down for me right now
, but based on
Audioholics' Perlisten double 12 review that sub is roughly equivalent in anechoic output but occupies a much larger volume than these four subs. So four 10s (admittedly with ca. 2kW of power total - but power is cheap and readily available today) in roughly 1 cubic foot total cabinet volume can yield similar SPL at 20Hz as a "THX Ultra" labelled single sub. In the real world a little less if you place the single massive sub for maximum room gain, but close enough. And obviously each subwoofer can be scaled up from these super-tiny things, which can lead to higher sound power or reduced amplification demands. Or scaled down, if one doesn't need/want that much sound power.
The caveat is box loading does matter if the goal is maximum ULF sound power in room from minimum subwoofer. Sealed subs without highpass filters work best for this approach, because the relatively slow rolloff means they'll pressurize room modes well below their nominal cutoff,. Many commercial sealed subs, such as most SVS models, incorporate static highpass filters that likely make them more likely to handle user abuse, but to some extent defeats the purpose of a closed box; why not do a PR and win the extra passband efficiency if you're going to cut ULF bandwidth anyway?