Is There A Big Difference Between Subwoofers From Different Manufacturers

What @mijostyn said, though I disagree with some of the prioritizations mentioned here.

With subs it’s mainly about capacity, design principle and implementation. Through this structural integrity of the enclosure and overall build quality should be "sufficient," but personally I find the need to make them inert/heavy in the extreme to be unnecessary. I’m not saying rigid, heavy cabs don’t make a difference, but to which degree and at what cost (in more than one respect)? Some may find capacity and implementation the most important, others implementation mostly, and others again (like @mijostyn) stress the importance of enclosure inertness (among other things). There are different ways to attain prowess augmenting the mains in the lower octaves.

Capacity, i.e. sheer displacement area and also sensitivity is very important in my book. All things being equal, the less those cones move the lower the distortion, and the less power needed for a given SPL the more headroom. Headroom in the lowest frequencies is paramount (where prodigious amounts of energy can be released), because more of it equates into lower distortion and a cleaner, more effortless reproduction. To boot ample displacement gives you that important physical feel and power of music - vastly overlooked, I find.

Design principle matters. Balanced force approach has been mentioned. By far most subs today use direct radiating drivers in sealed cabs, because this way they can be made as small as possible (and the cabs more easily inert) and retain extension. It’s is the most inefficient approach though, but in multiples this can be somewhat ameliorated. Still, sealed designs have max. cone movement at the tune (contrary to vented cabs and others), and moreover the exposed, direct radiating driver is prone to emit mechanical noise - not least when working harder, which smaller drives in sealed cabs and limited numbers do. Mechanical driver noise = distortion. I prefer large, efficient designs with partially or completely hidden drivers in either horn and/or bandpass variations acting as force multipliers, and with pro drivers no less than 15" in diameter. These designs also bring "inherent" bracing to their enclosures due to horn paths and other design innards, and build in plywood not least are structurally very sound.

Implementation has been covered already. I would also stress the importance of at least two subs, stereo coupling, symmetrical-to-the-mains placement and, preferably, a cross-over no lower than 80Hz. I’m aware this usually involves the need for high-passing the main speakers, and that quite a few audiophiles are against this. Such things would be more easily demonstrated with actual demos to highlight the potential advantages (depending on the ears (and preconceptions) of those who’re listening) of such a configuration, also to narrow down the specific setup context in which the high-passing of the mains has been done - which of course matters a lot to the outcome and to prevent unnecessary generalizations either for or against HP’ing of mains.

So, it’s about choosing the designs that accommodates the above, I find, and this not least calls for the need to include DIY solutions. I’d disregard brands if it means making subs very expensive to get some minimum of physical requirements. In other words, hugely expensive subs from the likes of Magico and Wilson Audio are a waste of money if you ask me, although I’m sure others may disagree. This is below the Schroeder frequency we’re talking about, resonators meant to move air efficiently, cleanly, effortlessly and acoustically well implemented. Trying to make subs into some dubious, "sophisticated" affair akin to selling the idea of expensive, single item (well, two for stereo) small 2-way standmounts is severely sidetracked marketing B.S IMHO.

@akg_ca --

Didn't see your post until after I had mine posted. You make excellent points. 

@mijostyn --

Re: driver size, I absolute agree with "The notion that larger drivers are "slower" is mythology to the max." It may (or may not) be interesting to note that the digital IMAX cinemas for a few years now have been using subs each comprising a quad array of 12" woofers (looks like (modified) Eminence LAB12's). I believe they usually have about 6 or 8 of those suckers installed in each theatre, and they're very powerful and clean sounding. Cinemas usually go with a number of ported dual 18" subs while some newer installations use 21"-loaded cabs, ported as well, but in any case it's interesting to see IMAX going the deviating route with multiple 12" woofers. Whether this is a consequence of a possible issue with lack of cone control in bigger drivers, I don't know, but in large cinema installations there'll be prodigious subs cone travel for sure.

The question is how lack of cone control in larger drivers (i.e.: 15" on up) relates to a domestic setting. A larger cone may be more difficult to control, but it also has to move less for a given output, and for cone control to be an issue you need cone travel to speak of. The cones of the 15" B&C woofers in my dual corner-loaded tapped horn subs only vibrate up to a few mm's at most at SPL's that seriously pressurizes the room; lack of control is a nonissue here, believe me. Remember the horn on the front side of the driver acts as a force multiplier, so with the combined and summed output of the backwave you have an effective air radiation about 3x that of a 15" direct radiating driver. And there are two of them, corner-loaded, hence it figures why the cones only move so very little, also explained with them having excursion minima at the tune. Bass like that doesn't force itself on you at ground level, but simply energizes the whole space around you very smoothly and effortlessly. Bass just happens as opposed to feeling delivered with effort. 

Yes, big cabs dominate the room, as my TH's would testify at 20cf. each. Corner-loaded though don't I feel it to be an issue, but seeing them out in the open they're just huge. 

@lalitk --

May I remind you that this thread is about seeking differences between commercially build subwoofers. If you and @mijostyn wish to further portray the superiority of DIY designs then I suggest you start a new thread. Thank you for your consideration and understanding.

... One can always contribute here objectively without showcasing their own prejudice or hatred for commercial builds.

As I said, "If you ask me" and "to my mind" - these are merely my assessments, and I'm in my right to express them. Instead of conveniently asking a few guys to enter elsewhere because what they're saying rubs you the wrong way, not to mention that you feel the need to act like an admin, why not address the matter without throwing "prejudice" and "hatred" into someone's shoes?

'Objectively' is certainly not off-base when the emphasize is physics more than brands, hence why speaking of the design aspect (or their variations) - whether it's DIY or commercial - is a primary focus that implicitly connects to what the OP is inquiring about. 

@mijostyn --

Right now it is two per channel and going to 4 drivers in two cabinets for a total of 8.  All the drivers are set to form a linear array so they all work as a unit as most bass is center channel. They are however hooked up stereo because I cross up at 100 Hz. As for overdoing it the limiting factor is space. I would use 15" drivers but the enclosures would have to be so big it would be impossible to fit them in.

Makes sense. Doubling the capacity from 4 to 8 units should see worthwhile results, not least also forming a linear array this way. Is avoiding the traditional approach of DBA distributing the subs throughout the listening space due to the higher cross-over frequency? 

@mijostyn

I wish I could find the link but is slow mo’s an 18" woofer under a strobe actually wobbling under light power. One side starts moving before the other and goes downhill from there. The excursions are not very far.

I know they wouldn’t make badass, neodymium magnet-fitted 21" pro woofers if wobbling/cone flex was an issue. What’d be an issue for them wouldn’t necessarily be one for us; let’s remember our domestic roofs would fly off over our heads if we where to test such driver at Xvar values, so it’s a practical non-issue with plenty of headroom even. These are very efficient, stiffly suspended drivers that can take from ~1.7kW on up, many of them tested at their limits in horn iterations firing into a compression chamber with uneven pressurization on the cone and huge cone stress to follow, and they eat it up.

I’m sure some drivers can driven to cone flex, but some aren’t all, and at what excursions?

I feel the most comfortable with 12" drivers and you can get to the same place by using multiples. I keep doubling the number until I get what I want. Next stop is 8.

Multiple 12’s can sound great for sure. And for your home setup you mean 8 per channel, right? I was under the impression you’ve implemented 4 per channel already.

I saw Marcus Miller and Mike Stern at the Blue Note in NYC last month and I could feel Marcus’s E string vibrate. It is that kind of authority I would like to get at home. I have great bass, just not that great. I know there are some recordings that can do it like Supertramp’s Crime of the Century or any number of Dave Holland Albums and Jaco albums not to mention Organ works.

Practically speaking I don’t believe you can really overdo bass capacity, unless the sheer volume of cabinetry becomes obtrusive acoustically. Actually, the problem is the other way ’round; the cleaner and more effortless the bass (via more displacement and efficiency) the more it can be enjoyed at proper levels in relation to the remaining audio spectrum - that’s is: you’d gain it "hotter" instead of, perhaps paradoxically, dampening poorer and more meager capacity bass performance.

Some of the vital impact of bass is diminished with central bass nulls (or suck-out) and softer floor constructions that can absorb quite a lot a of bass. In your case a column bass solution would be very appealing.

@lalitk --

... No disrespect to DIY’s community, but every DIY bloke thinks whatever ‘they’ can do, I can do it better. And please define better, what’s better or best to you or your fellow could easily be ‘good enough’ in someone else eyes. As humans we often tend to judge things based on our personal experiences and express opinions driven by our personal biases :-)

In relation to subs in particular the DIY community can have their cake and eat it too. By that I mean there're no physical restrictions other than what they impose on themselves, every design principle can be pursued - of which detailed plans are oftentimes shared for free, and the cost of assembly and parts is more manageable compared to commercial offerings - certainly with bigger subs. You can yell it to their faces all day long trying to convince them otherwise, but many if not most audiophiles would rather pay dearly for a smaller commercial package than letting size have its say via DIY (at less dough). If you ask me it's an audiophile "attitude" for main speakers that's extended, so to speak, into the sub octaves for how to realize that frequency span as well: with size restrictions (that mostly leaves you with sealed designs) and a particular attention to detail that strikes me as being more about brand identification than core physics.

So, with the lowest ~3 octaves it IS about what DIY offerings can do that commercial products can't, because size gets in the way, and to my mind that's an awfully restricted playground - expensive at that - to limit yourself to. 

@lalitk --

I see no sense in arguing with you further, nothing good is going to come out of it.

Except..

Remember it was you who engaged me, it was you who felt the need to advocate and pitch the superiority of DIY designs.

No, I didn’t engage you; I challenged/called out the general standings of commercial subs as being limited to mostly smaller, lower efficiency sealed designs, hereby forgoing a breadth of larger and more efficient design variations that more readily accommodates physics and, in effect, performance - unless a multitude of sealed subs with larger drivers (12" on up) are used. Surely I didn’t need to know the specifics of you and your setup to allow myself to engage in that subject? But now that you mention it I did look up your system, and it looks (and I’m sure sounds) beautiful - truly.

I couldn’t care less or more, cause I already expressed where I stand when it comes to commercial vs DIY subs. Next time you chose to engage someone here or another forum, learning first what they have posted and their beliefs will help you save time and embarrassment. It’s also called ’knowing your audience’ which involves identifying the audience and adapting a speech to their interests, level of understanding, attitudes, and beliefs.

How far do you think I’m going to succeed by pitching an idea of DIY cables to a guy who has a full loom of Nordost Odin or Synergistic Research SRX?

As per my paragraph just above. You’re pulling an ad hominem here, so let’s leave it at that.

My suggestion to start your own thread was based on your posts here and after reading your system bio. I knew exactly which camp you belong to and I respect your chosen path. It’s time that you open your mind to the fact that not everyone out there is inclined to build their own subs. Some of us are just happy with our choice of commercially build subs, irrespective of brand and price of admission.

As most who post here don’t go DIY with their subs implementation it seems to me trying to counter the commercial majority with a minority DIY approach for core physics-reasons outlined earlier isn’t uncalled for. You yourself called for "objectivity" in this discussion, and following an analysis (not least with poster @mijostyn's contributions) of design variations, overall implementation with the use of DSP tools in addition to build rigidity strikes me as accommodating just that. I hope focusing on these aspects tells one a thing or two about or puts into perspective to which degree (i.e.: relatively little) commercial sub brands may differ sonically, or at least that’s my assessment.

I know full well many if not most go the commercial route with subs, and I respect that - your choices as well, obviously. I’ve been there myself, done that. Not saying I drew out the most of its potential, but only so many iterations needed to convince me to search elsewhere, go active, include a separate DSP, high-pass the mains and a DIY route with subs to include design options practically not found in commercial offerings. And that’s that. Thanks for your time.