Subwoofers: Ported or sealed?

@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.

@jaytor --

It would be interesting to experiment with a pair of open baffle subs in a 2nd listening space and setup - they seem like a very capable design, not least as an overkill i.e.: über-sized option. 180Hz low-pass should be plenty enough to allow for a variety of design options above, like Danley’s Synergy horns or, like in your case, a line source.

Come to think it I listened to a pair of Quad ESL 63’s augmented I believe with a pair of open baffle fitted-to-the-Quad’s Gradient subs (dual 12" Peerless woofer per cab) back in the 90’s, and it was the best I ever heard the Quad’s. Indeed the pairing with the Gradient OB subs was excellent, and going by memory I’d favor that combo over the newer, more full range Quad iterations.

The TH’s are great for both music and movies, so yes, perhaps an OB solution wouldn’t offer the same versatile abilities here. Nonetheless they sound like an intriguing option.

@ghdprentice wrote:

Home theater is completely different… you want to rattle your windows. But for 2 channel audio it is really easy to do more damage than good and detailed discussions about sub woofer output bring up concerns of over use of subs.

Output and getting it right is really the least of it, I find. I agree many have their sub(s) dialed in too hot, because when they got subs they also want to hear them, and that's when it becomes a nuisance for any serious listening -  even with movie playback. Indeed, some home theaters have the subs dialed in ridiculously loud for effect, and to me it just becomes a load of huff and puffing mess that's all over the area. You don't hear that at most cinemas, I might add - at least here they got subs that don't sound as if they're trying that hard. 

Conversely there can also be the problem of a lack of proper LF-fullness, because a bass reproduction too conspicuous, colored, strained or otherwise will sometimes be negatively gained away so to hide its flaws. If on the other hand a sub sports low distortion (even at high SPL's), plenty of headroom and less of a distinctive mark you can dial back up the gain for more proper fullness and presence in the presentation. Maybe that's why with my previous, low eff. sealed subs that I had to add 4-5dB more gain with movie playback so to have proper impact, whereas with my current, higher efficiency subs I leave the gain where it is and being the same for both music and movies, and it's not for lack of impact and sheer visceral force with movies to be sure, nor the lack of a nuanced, natural and layered presentation with music. 

I currently have no subs in my main system, while there are two B&W 800 series subs in our home theater. While I consider putting a couple (Sonus Faber) subs into my system… I am enjoying the complete coherence across the audio spectrum. True, they only go to 28hz… but they sound fantastic.

Only 28Hz? Honest extension down to 28Hz is quite deep, and with added room gain they may more closely see into the low 20's. However, it's more about how those lower octaves are being reproduced than extension per se, and for that a pair of subs - properly implemented - may be a blessing to help augment this region more fully. Why not try out those B&W subs you already have, instead implemented with your main music rig, and see how that pans out? If nothing else to get a rudimentary bearing here. 

@ghdprentice wrote:

I actually had 4 B&W subs. Two for my audio system and two for my home theater. After I got these speakers I got rid of them. First I was very happy with the bass and coherence and I was liking less stuff taking up space.

Well then no need to toss around with subs - not even the Sonus Faber iteration, I gather. I'd always go for a pair of subs, but then again I go about it actively and treat the mains + subs as a single speaker system per channel in different boxes, high-passing the mains as well.