Are big subwoofers viable for 2 channel music?

@smodtactical --

Are big subwoofers viable for 2 channel music?

Unequivocally, yes. In fact, when practically feasible and without obstructing acoustics (and I’d go to great lengths to challenge named obstacles here), I’d much rather go with 2 big subs vs. 2 smaller ones to maximize and accommodate BOTH music and movie duties. Should you go quad-style immediately or eventually, not least with a room as big as yours, don’t settle for 4 smaller subs (i.e.: anything below 15"), because while they can make quite a load of noise, very clean bass even to a point, you simply won’t achieve the headroom desired, indeed mandatory if you want truly clean, effortless and relaxed bass at any SPL. "Enough" simply won’t cut it (it’s a severe "hifi"-disease to neglect the importance of headroom); much more than enough is what’s called for, be that 2 or 4 big subs, and once you hear/feel it, you’ll know why.

Luckily, headroom where bass goes isn’t as much about price as it is size (in addition to numbers). Offerings from JL Audio’s Fathom series, great as it may be, are simply overpriced, and yet the likes of Robert Harley would love to tell you that the Fathoms are exactly what big(ger) bass is about; that price necessarily follows size into the stratosphere. He is however, and sorry to put this bluntly, dead wrong and misleading here in his stuck-up high-end approach. Quality design, high efficiency, big size and proper implementation IS high-end bass reproduction, and it doesn’t require a minimum of 2" thick cabinet walls, luxury finishing, weighing half a ton and costing even more to get you there.

As I’ve stated previously: price isn’t the real issue here, size is, and by that I mean people are more willing to pony up the big dough for a smaller, more high-end looking product than going for the bigger, cheaper and more "unassuming" variant. Audiophilia will tell you it’s PA or home theater earmarked, not "hifi," and claim big size is just a bad, Mr. Simple Joe excuse to have bragging rights about exactly that: big size and SPL capabilities. Accommodating physics however, these are core parameters in the pursuit of great bass.

Tim --

...I’m fairly certain that 4K Ultra HD Bluray discs and streaming videos don’t contain any audio content below 20 Hz. I’m virtually 100% certain that no commercially available stereo music content, whether issued on LP, CD, SACD or Hi-Res digital file, contains any audio music content below 20 Hz because not one of the numerous individuals, that I’ve asked to identify a single specific example of a stereo music recording with bass below 20 Hz, has been able to do so. I’ve even searched for a single example myself without any luck. Can you name a single example? Anybody reading this thread know of a single example?

This is tangential to your former examples of arguments in the vein of "there’s no stereo information in the bass, neither recorded nor perceived; symmetrical placement of subs is moot (at a not specified cross-over frequency)" etc., and it goes to show what you’d like to feel better about while trying to convince others into believing as well. Sorry to be blunt about this.

Let’s make this clear once and for all: there IS content below 20 Hz en masse certainly as found on Blu-ray’s and UHD’s (look over at highdefdigest.com and their Blu-ray/UHD reviews, where there are occasional bass charts to prove there’re numerous examples of titles with infrasonic information into the single digits), and while I’ve seen no similar documentation on whether CD’s contain information below 20Hz I know of several individuals who have a music collection to strongly benefit from sub systems capable of much below 20Hz reproduction (compared to "just" having honest capabilities down to 20Hz), which is at least indicative of source material actually containing information in these "nether regions." Head over to the AVSForum and see with your own eyes the sub set-ups these people have in their homes, and ask them whether <20Hz reproduction matters. Visit databass.com and ask the same. The answer, I promise you, while be quite unanimous. People may not all agree on the priority of attaining infrasonics (and the compromises potentially involved here), but most won’t deny that frequencies down to ~10Hz (below that to truly matter requires rather massive radiation area and power to make a difference) are perceivable/felt, and can have a big impact on the experience. The proof is IN THE EATING of the pudding, but there’s documentation to back it up as well - should you feel inclined.

My main point, which I believe you likely agree with, is that it makes little sense to have an audio system capable of bass down to 6 Hz if there’s no HT or music content that contains bass that deep. Are you sure you’re not listening and feeling bass that’s going down to 20 Hz and just thinking it’s going down to 6 Hz?
In my room, even bass down to only 20 Hz sounds and feels very deep with powerful impact and realism on both HT and music. I don’t perceive I’m missing a thing.

With my own sub set-up I’ve consciously chosen to forego <20Hz because I favor bass reproduced from horns, tapped horns at that (this requires of you to actually buy into that bass isn’t just bass, be that via distributed arrays or not), and while infrasonics can be had with bass horns they simply end up being ginormous (so, a practical consideration), or with tapped horns in particular it means giving up extension in the upper frequency range, eating away sensitivity (though it’ll stay higher than any typical direct radiation sub) while continuing to have the physical size grow into behemoths when seeking an ever lower tune. When in my tapped horn subs the drivers move just a couple of millimeters with content down to 20Hz, I don’t feel I’m missing anything either - indeed it’s a visceral, awesome experience that shakes the air. I absolutely agree with you on the sufficiency felt here, although it’s not only about mere extension but also, and importantly about how these frequencies are reproduced.

However, I’ve heard what <20Hz can do when reproduced forcefully, and it adds a dimension difficult to describe other than it has emotional impact (as @jwmorris expressed above) and can also lead to a sense of unease and even intimidation. It makes a difference in particular with Blu-ray’s/UHD’s, and while I’m a movie buff and know of what I’m missing with my choice of sub system, I feel I gain sonically where it matters mostly to my ears, which is from ~20Hz on up.

Tim --

I had stated: "I’m fairly certain that 4K Ultra HD Bluray discs and streaming videos don’t contain any audio content below 20 Hz. " I believe my statement is generally correct ..

No, you are generally wrong in this specific instance. Why do you maintain to be "generally correct" when you admit the following (and is faced with facts/empirical evidence to prove otherwise):

.. but I’m willing to concede the fact that there is recorded sub 20 Hz bass existing on numerous 4K Bluray discs if individuals are willing to invest the time, effort and equipment required to retrieve and play it back. I’m not interested in doing so but I understand there are other HT enthusiasts that enjoy plumbing the bass depths of their HT systems.

The "time, effort and equipment required to retrieve and play it back" is one to be invested in any endeavor regarding sub(s) implementation, in fact the only difference here is acquiring subs that dig below 20Hz (and having sufficient power). Have your DBA set-up if you so prefer (in your case that’s a rhetorical question), find the proper (bigger) subs to delve into infrasonics, and voila. To boot: as poster @jwmorris referred to there’s the added bonus with bigger subs of having more headroom.

Phusis, your link on your last post to a Spotify site, that you stated lists music recordings containing bass below 20 Hz, did not work and connect me to this list. Can you please correct this and repost the link?

Let’s forward this to @jwmorris as the proper recipient.

You do realize that you conflated several separate but related bass issues when you stated ""This is tangential to your former examples of arguments in the vein of "there’s no stereo information in the bass, neither recorded nor perceived; symmetrical placement of subs is moot (at a not specified cross-over frequency)" etc., and it goes to show what you’d like to feel better about while trying to convince others into believing as well. Sorry to be blunt about this.", right?

What I pointed out with named examples was to expose and emphasize the nature of your argument, irrespective of the particularities brought up. You often seek to wrap up matters in a nice bundle of absolutes, or would certainly like to get to where (a fresh example) "anything below 20Hz is hogwash because we can’t ’hear it,’ and moreover there’s not really any source material to support it," because that’s what you’ve gotten into your head. It’s convenient even, and while we’re at it let’s try and have everyone else agree on it.

You conflated the separate issues of whether there are any music recordings in any format that contain bass below 20 Hz with whether this deep bass is recorded in stereo and whether individuals would be capable of perceiving the deep bass as stereo even if the bass below 20 Hz actually was recorded in stereo. My point is that all the following conditions have to be met for you to be correct about the viability of achieving true stereo deep bass in your system: ..

Again, as examples not intended to necessarily strike on a relation between them, going on from here is redundant. We have been confronted with yours and poster @millercarbon’s views in particular on the prowess of the DBA sub set-up ad nauseam (and you’ve learned of my views a couple times as well), and we get it. Duke’s (and Earl Geddes’) findings on this are by all accounts scientifically sound and very well thought out, but the whole concept, through your promoting it not least, revolves from a mindset of rigidity and reductionism that fails to give leeway to views, and not least experience of opposing nature.

For this conversation then, let’s focus on the latest subject for you to preferably shave into the size you deem fitting: <20Hz reproduction (and that it, to you, doesn’t amount to anything, in truth because your lack of experience here and theory-laden approach keeps you from knowing about it), which also naturally caters to and reverts our attention to the OP’s inquiry, whether big subs are viable for 2-channel music (and HT).

@millercarbon --

Everything Tim posted is right ...

Obviously it isn’t.

@millercarbon --

Oh, he’s right all right. You simply disagree. That doesn’t make him wrong. In this case it makes you wrong.

Let's hone in and focus on what's addressed here with a few excerpts of noble100's:

... your apparent endorsement of employing subs with larger woofers and in quantities beyond 4 subs to reproduce bass well below 20 Hz and even further improve bass performance, both surprises and somewhat confuses me.
    It's my understanding that reproduced bass tones below 20 Hz are not audible, mainly just vibrate things around the room including parts of our bodies, there are very few musical instruments that produce bass below 20 Hz with pipe organs being the only ones I'm aware of and there being virtually no commercially available music recordings containing bass frequencies below 20 Hz.
    I prefer bass that sounds and feels natural like when music is played, heard and felt live in person at smaller venues, not like over-amplified arena rock bass. What am I misunderstanding about music bass below 20Hz?

..and in a later post:

... My main point, which I believe you likely agree with, is that it makes little sense to have an audio system capable of bass down to 6 Hz if there’s no HT or music content that contains bass that deep. Are you sure you’re not listening and feeling bass that’s going down to 20 Hz and just thinking it’s going down to 6 Hz?
In my room, even bass down to only 20 Hz sounds and feels very deep with powerful impact and realism on both HT and music. I don’t perceive I’m missing a thing.

And that's just it: "I don’t perceive I’m missing a thing.," because he wouldn't know otherwise having no had the actual experience of the impact <20Hz can have. And that's OK if it weren't for the fact that theory trumps experience here, not in the sense of being in the right about it, but by letting theory have its say to presume he's right, when he's not in this case; experience, it seems, is irrelevant, and yet it would tell him, and you, that a rigid 20Hz barrier (or what's "audible") isn't the final word in bass extension. Not to mention the importance of headroom which is a "neat" takeaway with bigger subs, but getting through with that is futile when most would believe what they have is "enough." 

Probably your shoddy reasoning led you astray. Just look at what you wrote:

Duke’s (and Earl Geddes’) findings on this are by all accounts scientifically sound and very well thought out, but the whole concept, through your promoting it not least, revolves from a mindset of rigidity and reductionism that fails to give leeway to views, and not least experience of opposing nature.

Well, yeah, it takes feelings and "views" out of the equation. That is kind of the whole point of science and logic. You could look it up.

You conveniently left out 'experience,' which forms a view. It tells me a thing about you in particular; it's not that you can't listen (or so I presume), but rather that your reliance on theory (or "science and logic," as you so put it) won't get you to where experience could challenge your assumptions on audio. 

Only, why bother? The beauty of science and logic is anyone can learn to use them. They work very different from what you do, twisting words around trying to score rhetorical points. But unlike your word games they do in fact actually work.

My "word games" are simply trying to express the importance of letting experience (i.e.: listening) have its say, as per above. It's not that I'm oblivious to science and logic, I'm just weary of having it dictate what I'm hearing. 

@jwmorris --

As enthusiast enamored with our equipment, in our room, in our opinion we have to be careful not to be closed minded. I do not believe most enthusiast start with a great system. Great systems usually evolve over time. Most enthusiast come to a forum seeking advice and/or to learn from other people’s knowledge and experience.  

     We read, research, hear, or hear about a new way of doing things and we explore the new information. If we are open minded our joy of the hobby and our systems are improved. If we are determined to be closed minded, we do not grow. If we are determined to be closed minded we miss out on possible system improvements.

     If we insist our way is “The” only way we hinder/limit our own growth. If we openly criticize equipment and experiences with no credible experiences we could possibly hinder the growth of others. In those cases we should always remember to include “In My Opinion/Experience” etc.  
 
    I read more than I post. I try not to criticize anyone’s personal preference of speakers etc. I have heard multi-subwoofer setups. I actually considered purchasing a SWARM setup. I have experimented with a third subwoofer in my room. I have also experienced sub-woofer systems capable of Ultra Low Frequencies (ULF). I am very happy with my system but I am also very aware it can be improved.

     None of our systems are perfect. None of us know everything. None of us should attempt to invalidate the experience of someone else based on our own experience. The goal should always be to learn more/understand more. The goal should always be to improve and increase our enjoyment of music and the music playback systems. Some have forgotten this, others never knew it.  

Very well put (indeed above quoted post of yours should be a "sticker" on these pages), and I'm not saying this as someone necessarily complying in my actions with what you point out. I just know of it to be a commendable approach, and one to strive for. 

@noble100 --

I think our disagreements and differences expressed on this thread can be boiled down to a difference in preferences and priorities. I could go into detail but I believe it basically comes down to both of your top priorities seeming to be the optimum bass extension of your sub systems for HT Bluray 4K Ultra HD audio performance and my top priority being the optimum bass quality of my sub system for 2-ch stereo music hi-res digital music file audio performance. I think both are enjoyable and worthy goals. But why can’t we have both?

Even though I fully acknowledge the impact <20Hz reproduction can have and that there’s plenty of source material to support it, not least watching movies via Blu-ray’s and UHD’s, as I’ve stated earlier I’ve chosen to consciously forego infrasonics in my own set-up. This is due to the nature imposed by design limits mostly, in addition to practical considerations in regards to sheer size; tapped horns, my preferred bass principle, are bandwidth limited to covering about 2 to 2 1/2 octaves cleanly (some would say 1 1/2 to 2 octaves, but it depends on the specific TH design and its weighted parameters within the given fold/expansion/compression ratio), and therefore a lower tune will at the same time "eat away" of the upper range that can be achieved. For those not in the need of a cross-over frequency above 50-60Hz here, 15Hz honest extension (or even lower in-room) can be had from tapped horns the likes of which count Josh Ricci’s monstrous Gjallarhorn V2, the Danley DTS-10 or lilmike’s LilWrecker. Apart from upper range limitations naturally imposed on these designs there’s also size to consider as they climb upwards of 30 cubic feet in volume, not to mention the added weight that follows. Moreover, a lower tune with tapped comes at the cost of sensitivity, though relative to direct radiating designs they are typically still more efficient even when tuned rather low. My MicroWrecker’s have a ~23Hz tune @97dB sensitivity that gives clean extension upwards to about or just below 100Hz, and with a 78Hz lowpass in my system to the mains (36dB/octave Linkwitz-Riley) no irregularities from the upper band of the MW’s interfere in the presentation. Highpassing the mains above some 70Hz has advantages in relieving them more effectively, but the exact cross-over frequency is one to be found with careful listening. A highpass at 20Hz (4th order Butterworth) protects the bass drivers of the MW’s downwards as they unload below the tune (in domestic use mostly to reduce theoretical distortion rather than over-excursion), and so 20Hz is pretty much the "hard deck." With the pair of MW’s this translates to +125dB’s SPL envelope and honest 20-25Hz reproduction. Some may regard such SPL capabilities in domestic environments as insane, but when faced with the effortless reproduction they deliver at any SPL one would care for, even having impact down to 60-70dB’s, it makes perfect sense.

So, my preference and priorities revolve around attaining the bass that best integrates with my mains as well as acquiring prodigious amounts of headroom, and this requires going the (tapped) horn route with massive physical size to follow, as well as bandwidth limitations to consider. Infrasonics make a difference, for sure, but I’d rather attain optimum integration and overall bass presentation, to my liking, and sacrifice <20Hz with the given tapped horn design. Choices, and compromises.. (sorry for lengthy elaboration above).

@noble100 --

Hello phusis,

Thanks for your detailed response. I now have a much better understanding of your system preferences, priorities and goals. I looked at your system pic and description on your profile page and admire the unique and independent path you decided to take on your personal audio journey.
Your system certainly looks unique, interesting, beautiful and impressive, I’d love to hear it, or a similar one, in action sometime. You’re obviously telling the truth about the size and weight of TH subs. I like the looks of your subs and main speakers but, if I was to switch to THs in my system and living room, my wife would likely be chasing me around our house with a large frying pan targeted at my head.
I have a limited understanding of the appeal of horn speakers, their efficiency, sound qualities, dynamics and ease even at very high SPLs. The first pair of speakers I purchased as an adult in about 1979, was a brand new pair of the original Klipsch Heresy speakers, in unfinished birch wood to save some money, for exactly $300/pair.
I really enjoyed those speakers during college with a TT, 40 watt ss Yamaha CR640 receiver and no sub. I still regret not knowing enough about audio at that time to at least try using a tube amp with them. Now I use 1,200 watt class D monoblock amps with a pair of inefficient planar-magnetic speakers and 4 subs. Oh well.

Thanks,
Tim

Tim, thanks for your kind words, and apologies (on my part as well) for the delayed response. I looked at your current system via your profile, and I find it to be an impressive looking (and by all accounts -sounding) set-up. In many ways I imagine those Magnepan’s of yours to be speakers I’d enjoy. I take it they are very coherent, tonally rather accurate while yielding great scale and commendable dynamics (micro as well as macro)? Not to mention being highly resolved and presenting a huge soundstage? How would you describe their sound, and what about it in particular do you like? Your DBA sub set-up is likely a splendid augmentation as well. And that’s one great TV set you got there (I have the older LG OLED 65" B8 variant).

"Unique" and "independent" - even "beautiful;" your words flatter me. Well, I guess when I see something that catches my interest on this exciting journey of ours, and that speaks to the accumulated and randomly selected bits and pieces of info that enters one’s mind (and one deems important, for whatever reason), I go for it - not matter the consensus or gist among audiophiles. For some years now I’ve become progressively interested in the overall "presentation" of sound - that is, what’s the shape, if you would, of the "radiation bubble" (a phrase coined, I believe, by Tom Danley) that meets the listener: is it, preferably, homogeneous and of a whole, smooth sphere-like piece; is it more lumpy or diffuse even; of an oval shape, circular, or something else? Discerning the shape of said presentation is rather instantaneous, but it says a great deal about a pair of speakers ability to cohere (not least auditioned via mono recordings) and have the sound of each of the driver elements form into what would more or less successfully emulate a point source. This is certainly what I’m working towards with my own set-up, and I believe to be on the right path here, both with what I have now and perhaps even more so with the next "rocket stage" (not to be confused with rocket science) I’m on to.

Another hobby horse of mine is headroom, as you already know, and this is achieved more effectively with high efficiency designs - horns, certainly. It’s particularly important where bass goes as loads of energy can be released here, and many underestimate the sheer power and volume needed in the lower frequency spectrum (another recent thread on these pages brings this up). It’s not about overpowering the presentation with bass running the balance overly hot, but simply accommodating proper bass energy that’s effortlessly available at most any desired SPL. Anchoring the sound this way I find to be utterly important, and tapped horns are a great way to wring out the most of a given driver with minimal stored energy in this enclosure type and relieving the driver effectively; the tapped horn itself does the heavy lifting. Should you ever come to Scandinavia you’re most welcome to visit and have my set-up demoed.

Oh, the Heresy’s. Haven’t they been around for close to 60 years now? Never heard them, but I imagine they are very lively and entertaining speakers, musical even. Perhaps you’ll come full circle at some point with high efficiency speakers yet again, although at the risk of seeing that frying pan come into frightful use :)

@ oldhvymec --

... column can have a much larger volume, like 8-12 cf. or more. It’s easier to tune to a given room, and the roll off is much quicker mechanically. It’s much more controlled, like an infinite baffle, but can go very low, without the ever present noise from ports.

I friend of mine has spoken very highly of a set-up he’s heard a number of times that comprises bass columns (not IB). Some day I’ll have to hear them - I’m sure they hold great potential and coupling to-the-room capabilities, and with multiple drivers should have a nice amount of headroom.

Port noise can be a problem, and mostly is, but given enough capacity (i.e.: sheer radiation area and number of cabs) can be practically avoided, unless +120dB levels are your daily cup of tea. I prefer horn subs (make that 20 cf. per horn for a tune just above 20Hz), and while they’re less than easy to integrate in one’s listening space the coupling of the driver to the air (via the horn) is a vital part in them sounding the present and effortless way they do. Tapped horns, that I use, are also bandwidth limited, so knowing what you’re dealing with is paramount. Moreover the want for extension comes at the cost of sensitivity and adds size tremendously, so for me the "sweet spot" sits with a tune between 20-25Hz for a 20 cf. volume and 97dB sensitivity. In-room and corner-loaded a pair of them can output ~130dB’s, and this (i.e.: SPL envelope) is not trivial re: headroom.

What you don’t face with horn subs is port, or rather mouth noise. Theoretically I guess you could provoke mouth noise, but at that point the more dire urgency is that of dealing with blurry vision, structural instability and a desire to leave the building.

Columns are just better, but they are not usually partner pleasers and they cost more to build, The units I’ve seen and built can be very heavy, 3-500 lbs. BUT you get what you pay for, when it comes to bass.

Whether columns are truly better- to my ears, that is - remains to be heard, and I don’t agree paying large sums of money will necessarily grant you bass heaven. You get what you’re willing to house size-wise, and the effort and sense you’re willing to invest with design choice and implementation. Going the DIY-route (which is mandatory in the first place, I guess) this mayn’t be excessively expensive, certainly not compared to the über-offerings from the likes of JL Audio and a few others. The material quantity needed for bass columns I’m sure would not be cheap, though.

Just because there is a lot of it, and it’s everywhere, doesn’t qualify it as good bass. I’ve heard a lot of that over the last couple of years, now all of a sudden it’s the big craze. walk on subs through a room. LOL

What I don’t see is the blending, between low mids, MB, Bass and Sub
ALL are very important to address, not just squat and grunt out a sub/bass unit, like a pile of dung.. Geezzz. That’s "a way" though.. for sure..

Different ways to skin your cat. I’d agree an open mind with regard to bass augmentation isn’t always the most prevalent mindset on this forum now that the DBA approach in particular has taken hold on a sought consensus. Must make my acquaintance with bass columns, as you should with horn subs, be they Tapped Horns of Front Loaded Horns - if you haven’t already.

The distinction between music and Home Theatre reproduction as it applies to subs is notably expressed here. I used to run previous, smaller sub set-ups much hotter (like +5dB's) when watching movies - as an act of compensation, I'm now aware - vs. when listening to music only. Since I started using a pair of much bigger (20 cf.) tapped horn subs in my system there's no gain-differentiation needed with music vs. HT. Music isn't overpowered by a sluggish bass but is instead more naturally present and organically integrated, while movies have all the visceral force and impact, even potentially intimidating in nature, to truly make the experience felt.

Well-integrating subs IS about pursuing High Fidelity in its truer sense and certainly not like "added ketchup to some kind of gourmet food," but rather about making the intend of gourmet food taste gourmet in the first place. This applies to both music and HT reproduction; when the capacity is properly at hand you won't need "compensation" gain-wise in an HT-system, and it complements music as well. 

Indeed, great article. Josh Ricci knows of what he’s writing.

I’d go so far to say big subs aren’t only viable for 2-channel music, they’re wholly essential. The effortless quality of very large, preferably efficient subs means the cone(s) move very little, and it’s directly translatable into lower distortion and cleaner, more tuneful bass. Either you use a bunch of large diameter direct radiating drivers, or you horn-load a fewer number of them for what’s effectively a similar air radiation area, but a differently perceived bass presentation (one that I prefer, I might add, but to each their own).

I guess with regard to subs you could say: by and large, buy ’em large (and plenty of them) :)

@noble100 --

Thanks for your follow-up.

I think we must careful not to make ourselves the judges on the level of ambition and complexity to dictate in this matter, but rather to relevantly pursue the subject of this thread to the fullest extend possible. At its core linked article by the OP simply tries to debunk a general assumption within audiophilia that larger drivers are slower sounding than smaller dittos, and indeed some perspective is given into this by Mr. Ricci. The general "math" behind it, as presented by him, isn’t that hairy, and in any case there’s the choice of going ground-up by yourself, or implement shared, existing knowledge in the form of actual, specific DIY designs. Or, you could simply buy pre-assembled, large subs and be done with it easily (not to take lightly proper integration/implementation) - they’re out there the likes of JTR, PSA, Deep Sea Sound, Funk Audio, Danley Sound Labs and others.

What is your reply other than to essentially advocate, or indeed advertise for a multi-sub set-up with smaller drivers? We know it works excellently, yes, but sorry - it’s not the primary relevance of this thread. The OP asked whether BIG subs are viable for 2-channel music, and they most certainly are while bringing to the table possible advantages few get to experience, because large size isn’t desirable or otherwise allowed for. Nothing holds anyone from going the DBA-route with big subs - now that would be awesome, and with proper designs it’s a win-win.

And yet, I’d go on to maintain the following: personally I’d rather have two symmetrically placed, very big and efficient subs vs. 4 small-ish lower efficiency subs in a Distributed Array. It’s what I have (2 BIG subs), and have very deliberately chosen. Would I want two more of them? Hell yes, if space and economy allowed, which unfortunately it doesn’t at the moment. As is though it’s a treat, and it would take something like 2x ported dual 18"-loaded subs to equate a pair of 15"-loaded tapped horn subs that I use. It’s not bragging; it’s underlining the importance of headroom and sheer air displacement capacity, and what it does to the bass presentation and how it integrates with the mains.

For a large space like the one initially lined out by the OP (or be that even a smaller ditto), serving home theater duties to boot, I'd wager to keep the thing of it all the most "musical" - i.e.: with low distortion, effortless and smoothly distributed bass - is to go with two or more big, higher eff. subs. Many seem to be hellbent on the "multiple smaller subs vs. fewer or only a single big one" division. For Pete's sake, what's with the self-imposed limitations? Have your cake and eat it too with a bunch of large subs like the ones from the reasonably priced and quality items PSA, and make them no less equipped than with 18" diameter woofers. These are high eff. pro drivers with a moving mass to cone diameter and motor force ratio that in no way makes for "slow" bass, contrary to some high moving mass, very low eff. (<85dB's) woofers meant for ultra small sub cabs with a bass reproduction that never really "gels" with the mains. Yes, very generally large, high eff. subs to my ears sound somewhat more musically "right" and well-integrated, because you don't sense they're using any real effort reproducing bass with their large diameter cones that barely move. Sonically in some regards REL subs are one of the more notable exceptions from the small cab/low eff. "camp" being not least they don't try and squeeze out infrasonics from their designs, that would have otherwise necessitate a higher moving mass in the driver and thus resulted in even lower sensitivity and likely bass lag. But, again: big (higher eff.) subs are not only viable for music reproduction; they would seem wholly essential if you ask me, while providing for a very worthwhile impact watching movies as well. What people won't do to avoid size in subs, and the hassle this has a tendency to bring with it (sometimes unknowingly, because they haven't heard the difference). It may even come down to large size being judged as "not looking cultivated enough," or "too brute for hi-fi." 🙄 When you got the space, use it. Bass properly sized/scaled is all the better for it.