Dual vs single sub

I made my secondary subs coffee tables :) An inch thick piece of glass in top with a lamp and no one even knows they are speakers, the WAF went way up at that point.

I agree with many above, four subs is the way to go, independently powered and signal driven through a mini DSP gives you flexibility to add room correction through room measurement via Room EQ Wizard (REW) in conjunction with Multi Sub Optimizer (MSO). My mains are passive subs running off of a Pass Labs X-250 and the secondary subs are SVS SB-16 Ultras which have their own amps built in. All are connected via balanced connections. The bass is accurate, powerful, and adds so much to music and movies. I add a little bass in my movie setting and had friends jump out of the couch a few times during a recent action movie. Pure fun. 

Hello hifidreams,

     You're obviously well acquainted with the benefits of 4-sub dbas through personal experience. What exactly does your sub system consist of? 4 SVS SB-16 Ultras, a mini DSP with REW and a Multi Sub Optimizer?
     Your post makes me think of a couple other points worth mentioning:
1.  No one using a 4-sub dba, or anyone who has just personally experienced the excellent bass performance of a 4-sub dba for even a short demo, needs any further convincing of how amazingly well this concept works in practical terms, at this point you're just preaching to the choir. The icing on the cake is that it works equally well in virtually any room and the sota bass response integrates equally seamlessly with virtually any pair of main speakers.
2. Once you completely understand how well the dba concept works and you'd like to spread the word to others of this fact, I've discovered that writing or speaking about the virtues of dbas is likely the least effective means of convincing others since it sounds too good to be true and people remain skeptical. I think the most effective method is definitely just sitting down in a room with a decent dba system for a good audition. A good dba demo is worth at least 1,000 words
     I understand the skepticism about 4-sub dbas very well because I initially also thought it sounded too good to be true and I remained skeptical for many months before a free 30-day in-home trial period offer convinced me to give the AK Debra dba a try.
     I had dba skepticism because I had no experience with, or even knowledge of, the concept.  Now that I do, I've been transformed into a complete dba fan and promoter.

Tim,  

Hi Tim,

    I have two Kinergetics SW-800s (each has five 10” Seas drivers in their own enclosures wired in parallel) driven by a Pass Labs X-250 and two SVS SB-16 Ultras in my room. I have an active set up using a Mac Mini maxed out with SSD drives using JRiver playing lossless FLAC to my mini DSP via optical out. The mini DSP is processing 24/96 with 8 balanced outputs with 12 biquad filters on each channel which were created using REW and MSO. My main speakers (Magnepan 20.1’s) run full range. Highs/Lows of each Maggie have their own channels (4) and each sub has its own channel (4). 

To tackle the Herculean task of attaining perfect base I have spent almost as much money on my subs as my 20.1s. That is how much I believe it is important to get this aspect of the system correct. Proper base is essential to all music, I want a tympani to sound like it and make my chest reverb with a strike as it did when I played in an orchestra. Lower octave listening, even the vibrations you can’t hear but feel are foundational to the live experience. Those waves are dissipated in a concert hall but build up in a room and bloat the sound unless it’s done right. I’ve heard a lot of excellent systems and many top of the line speakers will not tread near 16Hz because they know it will be a mess in most rooms. 

While i get that many people will not go to my extreme to get perfect base having 4 subs of reasonable quality disbursed in the room can really make a system sound complete. When properly set up the bass is tight and integrates seamlessly into the system.

The most common statement upon seeing my set up is, “I bet you could blow out the window with that! Why do you have so many big speakers?” “It’s for accuracy,” I say and then ask to play their favorite piece of music. The first impression in listening to my system from non audiophiles is how “clear” the music is and that has everything to do with proper bass integration and room correction. I can turn up the volume to concert levels and it doesn’t seem “loud.” Yet when watching a movie where a tank rolls by the ground shakes, your gut gets a strange felling and  stomach makes a flip just as you would if you were standing next to it; shots hit you in the chest and make you jump. 

I agree with you. I can talk all day about how important it is but hearing is believing. All of this is not that hard to set up either. I followed a tutorial on REW and made some measurements. Did another tutorial in MSO when I was learning and plugged in my own data after seeing how it worked using the tutorial files. Spent a day having fun adding and refining it. It’s so exciting to experience how big a difference is realized when room correction is done right with an integrated sub system. 

My last piece of my system will be BACCH for Mac. . . Saving up my coins now!  

Happy Listening,
Steve

@millercarbon --

The Ford Motor Company did a study some years ago, to determine what exactly was needed for really good bass. What they found is that below something like 80 Hz the bass on virtually all recordings is mono.

I just got my Swarm-based distributed bass array up and running last night and so I can now say from factual actual experience there is nothing else like it. If you want really good bass you will use FOUR subs distributed around the room. Period.

Why try and make a case with a limited number of CD’s (what genre, age of mix, etc.?) to conclude that there’s virtually no recorded true-stereo bass? It’s the problem of induction all over again, and a neatly sought closure to support an argument that may know full well the problematic issue of playing stereo information from sound sources (i.e.: subs) that aren’t placed symmetrically to the mains, insofar they’re crossed high enough for it to matter (which, I’d wager, could be an issue even if crossed below the rigidly fixed 80Hz). So, mono is the solution, preferably crossed rather low for the 4-sub approach to make the best of it, timing with the mains being the lesser concern and not drawing on the potential benefit of high-passing the mains (from ~80Hz or so on up to make the most of it). At times this even boarders on the scent of a subwoofer inquisition that calls heresy on anyone who’d dare not to see the divine light of multiple subs.

Fore sure, multiple sub sources scattered throughout the listening room in mono can sound absolutely great - the latest of which I’ve heard comprised no less that 6 Front Loaded Horns each fitted with a 15" driver tuned at ~25Hz (20 cubic feet cabinet volume per horn), and it was a blast both in quality and quantity (that is, 4 of them were placed front center from the ceiling in a cluster with all mouths facing each other to form a single mouth, while the last 2 of them were placed along the rear wall, so essentially this wasn’t a multiple sub approach as advocated here).

What really annoys me though is a prevalence to factualize a sub-approach (i.e.: the 4-sub mono one) as the one and only high quality solution, when there are other viable solutions like a 2-sub approach - in stereo, crossed significantly above 50Hz, and placed symmetrically to the mains. If mono-bass is your thing, or certainly the argument of it, then a pair of stereo-coupled subs will still play a mono signal as such, but if classical material or electronica in particular should muster up a stereo signal here for an intended effect or to support a spatial element, then true stereo-coupled subs placed properly (to the mains) will grant you this aspect of the music additionally.

Further I’d suggest being open to other principles than direct radiating subs, which are by far - dare I say exclusively - the bass principle of choice around here and audiophilia in general, perhaps even blindly. Horn subs aren’t really sold commercially other than from pro vendors, and while also being quite large it’s understandable many mayn’t have been exposed to their traits in a home setting, but this is also the problem: most simply don’t know how horn subs sound, and because of this (and their being used in pro-sector applications) likely make assumptions on their sound that are far removed from their actual imprinting. Quality horn subs, which are mostly available via DIY-solutions, to my ears sport a level of refinement, ease, smoothness and enveloping presence that no direct radiating solution that I’ve heard can equal, and this is obvious whether a multiple sub approach, 2 of them or even singles is used. While you would think first and foremost that a horn sub (some 30Hz extension minimum requirement for it to be called a ’sub’ and not just a bass bin) to be perhaps more of a more brutal, chest-slamming experience than a smaller DR solution (which it can be at elevated levels), you’re likely oblivious to the traits mentioned above that are prevalent at more normal listening levels as well (i.e.: 60-90dB’s, whatever floats your boat) - traits that should be considered and pursued by every audiophile.

So then, it’s not my intention to bash the multiple sub approach, which I know can sound great, but for some to ease up a bit on this being the only proper way to implement subs in your home setup. 

EDIT: one could of course combine a true stereo 2-sub setup with 2 additional subs in mono placed more "freely" in relation to the mains.