@jaytor wrote:
Another option to consider is open baffle, if you have the room. I am really enjoying the bass from my open baffle subs, and prefer the bass quality compared to the sealed and ported subs I have had in the past. To me, it sounds much more natural than box subs - smooth, clean and dynamic, without pressurizing the room and without the boxy resonances that many box subs have.
Your open baffle bass/subs approach is an interesting alternative. I’ve heard a range of open baffle main speakers and generally liked them, but have never truly considered open baffle as a bass/subs tower option only. How high are you crossing them to the mains - indeed, how high can they be crossed?
Going by your descriptions they seem to share at least some characteristics of horn-loaded sub variants. Myself I’m using a pair of tapped horn subs (a Tom Danley patented design, though DIY’ers are allowed to roam freely making their own versions), fitted with 15" B&C pro woofers and tuned at approximately 23Hz. With a 20 cf. volume per enclosure they’re some bulky critters, but that’s the price when you need fairly deep extension in addition to higher sensitivity (97dB). They’re high-passed @20Hz (36dB/octave BW) because of the unloading of the woofer below tune, if mostly to alleviate any added distortion here.
Anyhow, few realize the smooth, effortless and immersive bass TH’s can produce, because hardly anyone have heard them in a home environment. It’s difficult to describe, but the bass of TH’s is just there in the room as this immersive presence; you don’t sense the bass being produced by cones with any effort, and as such it’s actually a rather "civil" though visceral bass reproduction compared to direct radiators (be they ported or not), that by comparison - to my ears - draw more attention to themselves. It would seem though in your case with the open baffle subs that they’re not a typical representative of direct radiators.
Some 5-6 years back I used a sealed 16" sub (SVS) and later added a 2nd one on loan to see how that panned out. Two of them no doubt was the preferable solution, but after quite some experimentation I still couldn’t them to gel in a satisfying manner with my then all-horn main speakers, and so I scrapped them both and went with the TH’s instead.
To say it made a difference is an understatement. The SVS’s went slightly deeper (infrasonic territory) and had a nice clean punch, but compared to the TH’s they simply felt compressed with bad layering, while lacking in central bass agility or "aliveness." The TH’s have a smoother, fuller, and slightly warmer imprinting with zero overhang - something that, conversely, marred the SVS’s - not to mention that the TH’s can be downright scary in their visceral-dynamic prowess and SPL capacity, and even so the B&C woofers barely move.
If given only the choice of sealed vs. ported, I’d go with a pair of large, higher efficiency ported subs (say, dual 18" or single 21" per cab) with a relatively low tune. Or, 21"-loaded 6th order bandpass designs with prodigious port area on one side of the cone, and short horn-loading on the other.