Single vs. Dual Subs

Hi divertiti, 

As someone who has had a variety of two channel monitors over a long period, differing rooms and challenges, I've discovered that a pair of subs properly matched to the personality of your mains is terrific.  My sealed subs are positioned below my monitors, with a radiating pattern that integrates nicely with the mains in a fairly nearfield, small room, well away from front and side walls.  My pro dac steeply rolls off 80hz down to their tube amp for the mains and the subs from 80 down to the high 20's with purity and resolve. This arrangement makes for a very coherent and near full range presentation.  The disappearing tricks of great monitors, staging, et al work their magic,  with appropriate slam.  I considered a swarm but decided against it in a small studio.  Bonne chance, divertiti!  More Peace, Pin

divertiti, I have a similar situation to you, relative to Sub Woofer Placement.

I solved it, which IMHO, has optimized the results, as follows.

Here's my solution:

1) Set of 12 inch, self powered 500 Watt Subs at Far Left & Right of room, set @ 70 HZ Crossover.

2) Single 15 Inch Sub Directly in Center.  This Sub Woofer is Fed its signal from a dbx 234S Electronic Crossover set @ 40 HZ Crossover Frequency, & set to SUM Left & Right Channel Inputs, which signal is in turn fed to a Classe 25 in Mono Mode, putting out an honest 1,000 Watts.  dbx 234S gets its signal directly from the second output of my pre-amp.

3)  Combined with PS Audio BHK  Signature 300 Mono Blocks, feeding a pair of Anthony Gallo Acoustic 3.0's, three way speakers.

This combination of Speakers puts out Exceptional Non Boomey Bass with Massive Slam, as the 15 Inch Sub Woofer is driving directly into one, when they are sitting in the sweet spot.

I find the "Single Very Low Bass Sub", summing both Left & Right Bass signals to be optimum for Deep Bass, while not interfering with the music that one plays.  

It is all summed at that frequency anyway. But, whatever.

“Two or more subwoofers also help in reducing low-frequency distortion and offer improved dynamics over a single subwoofer. This is a simple function of having more radiating area, plus more power on tap.”

 I suspect that we all understand that bigger drivers and more powerful amps are usually good for bass. ‘Twas ever thus.  But many of us have $, space and spouse constraints.
I’m considering getting sub(s).  My question is more like, “for the same money, are 2 10” subs likely better than 1 better (and more powerful)  sub?”   E.g., 2 REL t/9i vs 1 REL S/510 cost about the same. 
For that matter, is there a consensus (here? Lol) that REL is likely better for 2-ch than JL Audio or SVS?

All IMO:

• the most bang for the buck are the Martin-Logan x series. Complete control set, available Perfect Bass Kit make integration a doddle.
• JL Audio are very good, but pricier.
  
• REL ain't what they used to be and are more jewelry than engineering. Their web malarkey is geared to the uninformed and WAF wimps.
• Never heard or used SVS

My perspective is from fidelity and integration standpoints. If you want to be punched in the stomach [which does not happen when recording a kick drum] I'm outta my depth.

see  ieLogical SubterraneanHomesickBlues for more info and a primer on integrating small subs.

1. mc ~ " It is all summed at that frequency anyway. But, whatever. "

2. Kindly explain HOW, in your opinion, that happens???

Why am I required to explain HOW?

What if the HOW is automatic? What if it turns out the HOW cannot be anything BUT?

The wavelength at 80Hz is 4.3m or about 15 feet. At 20Hz it is over 17m or about 55ft. https://www.translatorscafe.com/unit-converter/en-US/calculator/sound-frequency-wavelength/ HOW are you going to ever manage to record that in "stereo" with any sort of ability to localize the sound without using microphones placed at least that far apart?? And in a room many multiples of those dimensions?

HOW are you going to do that?

Even if you do, HOW are you going to manage to play it back in stereo, in a room with dimensions smaller than the wavelengths involved?

HOW?

mc, Why state the obvious, then attempt to justify it?

Why have two Low Bass Stereo SUB Woofers, when as you state it's difficult to record  Very Low Bass Frequencies in Stereo?

Wouldn't summing Left & Right Low Bass Frequencies Electronically, (which can be done efficiently, with a Summing Electronic Cross Over) then playing them back from a Central Low Bass Sub Woofer, as I suggested, provide a better option?

As I indicated, I still have Stereo Bass from my 12 Inch Sub Woofers for Localization of those Mid Bass Frequencies; via their placement on far left & far right, which provides such localization for those frequencies.

Providing Very High Power to a Single Centralized Low Bass Sub Woofer definitely puts the SLAM into those frequencies, which can be felt, but not heard by most people.   

Try it, I guarantee that you will like it!

eagleeye7

  
 

Properly integrating a sub is really hard work, and rarely done by 90% of those who buy a subwoofer.

As a result most audiophiles have never heard a single subwoofer properly set up and think that stereo subs matter for the sake of Left/Right imaging or sensation. They do not if you set them up correctly.

They matter for frequency smoothing, and then only in cases when you have absolute control of their placement, and then, only somewhat.

Better room acoustics and EQ can make a single sub sound glorious and enhance the experience from dual subs as well.

Most audiophiles also try to stick to subs below 40Hz, when in fact cutting off their mains at 80Hz or so tends to greatly reduce doppler distortion (assuming small 2-ways) and increase the amp dynamic range.

Sadly people tend to want to just throw money at a problem that needs expertise. Hire an expert, or get a system with built in room calibration and sub management. You’ll be really glad you did.

Amen!

Properly integrating a sub is really hard work, and rarely done by 90% of those who buy a subwoofer.

Technically, correct! I would even go as high as 100%. But 90 will do. Which is why I always and only recommend a DBA with 4 subs. Try and do it with just one and you are doomed to failure. When even the guy who uses one knows it is really hard work, and even then works only rarely, everyone should listen. 

And then go out and get more subs. To do it right. 

My listening room doubles as living room so sub placement was dictated by furniture. Even so the Audiokinesis Swarm sounded fantastic out of the box. I am sure I could fine tune it if I had a dedicated room but this is already wonderful with minimum effort

I am currently running two subwoofers. It’s not talked about much but the biggest improvements come in mid range clarity And the highs have a little more pop also not to mention increased soundstage and detail. I also found out that the best sound that I got was from stacking my subwoofers so don’t be afraid to experiment !!!

Okay, so if going with dual subs, can you mix and match sub brands? Seems like sticking with the same driver size may make a difference. I have a Paradigm x10 but was thinking of pairing that with Sonus Faber sub to pair with my SF speakers, but I might be better to go with a second x10. Integration with the same brand seems obviously a lot easier.

"Seems" and "is" are two very different things, for sure when it comes to subs. Duke makes his Swarm with plugs enabling you to convert one or more ported subs to sealed. After studying the matter and talking with Duke mine were made with two ported, two sealed. I also have a 5th sub that is ported iso-baric.  

The truth of the matter is there is no "integration" process with a DBA. You plop them down, you set the levels, they are "integrated" whatever that even means. To me it means the bass is seamless with the rest of the sound stage. This happens automatically. You could use five completely different subs or five all the same, no difference. So save your money. 

divertiti, It is impossible to perfectly tune a single sub so that it's frequency response is flat at any listening position in an enclosed room.
So, you can live with a single defective subwoofer or minimize the damage by getting two. Depending on your main speakers two may be enough.

Perfectly flat, no. With a bit of room correction on the mains, the REL B1 ran 100Hz down to 31Hz, +/-2dB in the listening seat, and the sub's location was invisible (low pass 23 and low vol).
Still, the B1 went into the home theater and now have three sealed SVS subs (3000 and 2000s) in a DBA type array, which is better than the single sub.