Dual vs single sub


Sorry Im sure this is all over the forums but I only found old articles. Situation. I have Two SVS 3000s that arent really doing it for me. Thinking of trading it in on the Big one and adding another in a year or so. Any thoughts on Big single vs 2 Medium?
128x128bryantdrew
gdnrbob,

     I have my 4 subs connected to a single amp just as Duke described.  It's all fairly basic but I would suggest having a plan for running the wiring.
     In my case, my living room is directly above a crawl space and I drilled 1/2" holes through my living room carpet and sub floor for access. I have a hole in back of my rack that holds the Dayton sub amp and a hole underneath each of the 4 subs.  Remember, the spkr terminals are on the bottom of each sub and there's the option of using spiked or flat footers.  I ran thickly coated 16 gauge wire suitable for outdoor use which wouldn't be needed indoors.
      There are a lot of methods you or a ht installer could use to run the 4 sets of wiring inconspicuously.  I'd definitely recommend hiding the wiring, however, since the finished look is so clean and even stylish.  All that's visible just looks like a wooden pedestal. 
      In my 23x16 ft room, each of the 2 subs positioned along my front 16 ft. wall are actually hidden from view by each of my 6x2 ft. panel speakers.  The 2 other subs, one along each of the 23 ft. side walls are visible but look good to my wife and I.   
     Oh yeah, and the whole system sounds awesome.

Tim
        
millercarbon,

     Yes, you'll be amazed just how well it works.  Have you given any thought about positioning your 4 subs in your room?  If not, I can detail the process I used that worked out very well. 

Let me know,
    Tim  

"One question concerning 4 subs - How are they connected to the amp?"

The amp I supply with the Swarm is the Dayton Audio SA-1000, part number 300-811 at Parts Express.

It has a single channel of amplification but two sets of output binding posts wired in parallel.

The subs are connected in series-parallel, such that the four 4-ohm subs present the amp with a 4 ohm load.

Two subs are connected in series (via binding posts on the bottom), forming a two-sub "series string". Then the other two are also connectged in series, forming a second two-sub "series string". Then the two "series strings" are each connected to one of the sets of binding posts on the back of the amp, which puts them in parallel with one another.

Going into a bit more detail, the first sub in each "series string" has two sets of binding posts. One set is connected to the amp, and the other set is connected to the second sub in the "string", which only has one set of binding posts.

So you’d need four sets of speaker wire: Two sets go between the amp and each "first" sub of a "series string", and the other two sets of speaker wire go between the "first" and "second" subs of each "series string".

Some people use two amplifiers, typically one for each series-wired string, for a bit more flexibility.

"Stacked spades/bananas?  Seems like a lot of hardware to me."

No stacked spades or stacked bananas.

I guess it’s a lot of speaker wire. Unless the runs are really long, sixteen gauge wire works just fine. You end up with the equivalent of thirteen gauge wire because of the series-parallel topology.

Duke

One question concerning 4 subs-
How are they connected to the amp?
Stacked spades/bananas?
Seems like a lot of hardware to me.
B
Yes four subs is the way to go. Which is why I am going that way. Frustratingly close to being done and able to offer first hand opinion! But I know it works. Or I wouldn't be doing it.



The idea of 4 subs is the correct one. In case its not clear, the problem is standing waves and this is not easily corrected by room treatment if it can be treated at all.

But its easy to treat with 4 subs. Just do what Duke mentions above. He's a modest individual and didn't mention that he makes some of the best subs out there- the Swarm, which comes in sets of 4. Two of them are placed asymmetrically in the room and it is this placement that breaks up standing waves, allowing you to hear all the bass notes at the listening chair.
bryantdrew,

     You haven't stated whether you have two of the larger,ported SVS PB3000 or the smaller, sealed SVSSB3000 subs.  It'd also be useful to know whether you're going to use these just for music, just for ht or a combination.
     I'm very confident that either the Audio Kinesis Swarm or Debra distributed bass array system will outperform any pair of subs of almost any size and price for music and ht.  Both are priced at $2,800 for the complete system which includes 4 subs(each sub is 4 ohms, 1'x1'x23",44 lbs, has a 10" long-throw aluminum driver and have removable port plugs so they can be run as ported or sealed.) and a 1,000 watt class AB amp/controller that powers all 4 subs and controls the volume, phase, crossover frequency and has limited e.q.
     All 4 of my AK Debra subs are configured as ported and operate in mono mode with a flat frequency response from 20-100 Hz.  I have a combination 2-ch music and 5.1 surround sound ht system using Magnepan planar magnetic speakers across the front (a pair of 6'x2' 2.7QR panels that have a deep bass limit of about 35 Hz  as mains and a CC3 center channel that has a deep bass limit of about 50 Hz.  I run all these speakers full-range with the cutoff freq.usually at 40 Hz for music and 50 Hz for ht. 
     The Debra or Swarm system provides natural, pitch-perfect, taut, articulate and dynamic bass that seems to effortlessly go as deep as the content requires and integrates seamlessly with the mid-bass to treble response from my main speakers on music.  But the system also provides these same bass qualities  along with the ability to provide deep, powerful, dynamic and accurate bass at high volumes that will shake the room when the content requires it on ht.
     I think one of these DBA systems would perform equally well in virtually any room and with any speakers.  I really don't believe it's possible for me to overstate how well this concept works and just an audition would convince almost anyone.  I'm certain that an AK Swarm, Debra or even a custom DBA using a sub amp and 4 subs of your choice will significantly outperform any system using less than 4 traditional amplified subs of any size or price; definitely in bass quality and probably in bass quantity and impact. It truly does provide sota bass response that I've never been able to equal with 1 or 2 subs of various brands in my room and system.
     It's also relatively inexpensive at $2,800 for everything but the rca interconnects and speaker cables, about the same price as 2 SVS PB3000 subs or a pair of many other high quality subs.
     I'm not a retailer and have no association with Audio Kinesis. I'm just a very pleased customer  trying to spread the word about how exceptionally well these DBA based systems actually perform.

Tim

mijostyn wrote: "I think Noble is on the right path here..."

And I think you’re on the right path too. Your idea for spacing four subwoofers along the front wall will greatly improve their interaction with that end of the room.

But here’s the thing: The rest of the room matters just as much. Here’s why:

Unless you have a very large room, by the time you even BEGIN to hear the bass energy, reflections off the rest of the room’s boundaries are fully in play. So Noble’s approach of modal smoothing throughout the room is imo better aligned with known psychoacoustic principles.

That being said, once you have four subs, there are a LOT of different things you can try.  See the writings of Earl Geddes and Todd Welti. 

Duke


I think Noble is on the right path here. Look at the difference between the radiation patterns of point source and linear arrays. The trick is in creating a linear array woofer. If two drivers are closer than 1/2 the wavelength of the highest frequency they are to reproduce they will act acoustically as one driver. The wavelength of 100 Hz is around 10 feet. So, if you space subwoofer drivers 5 feet apart they they will act as one driver up to 100 Hz. Say you have a 15 foot wall. Space 4 subwoofers at 5 foot intervals along that wall the outside two being right in the corners. The other two in the center should be pointed at each other with the drivers as close to the wall as you can get them. What you have created is a horizontal linear array subwoofer which minimizes room modes and reflections and takes full advantage of intersection gain. 12" drivers are way more than enough. Many will do fine with 10" drivers. 
@don_c55  
 
You almost never get stereo bass unless your room is very dead and you crossover high. I have a single sub crossed at 80Hz that’s decently far from my speakers, and in my wooden-floor open floorplan with no treatment other than a rug, I almost never hear where it’s coming from.  
  
@bryantdrew  
 
I would say dual Rythmik F15HP, dual bundle brings it to <$2400, they are very “musical” and are +/-3dB down to 10Hz! I mean, if you have money to blow there is also their F18 :).

I have (4) JL Audio F-113 subs with my 2 channel.  You can never have too much subs. The problem is that you don't want to have so much bass that it drowns the mids. That being stated, I have a DEQX unit that can dial in the subs to work well with the mains. 

BTW, when I use my Hometheater equipment there are 4 more subs added to the 2 channel set up.

ozzy
I hope I did not make any comments that broke rules that hurt anyone, that was not my intent. Oh maybe profanity?
I think my purpose is SPL but as a result better sound.  I don't know if anyone has ever heard Phil Lesh hit these certain bombs, when that happens I want to feel it. During regular listening I want it to sound better than good, but never overpowering.  Listen, I'm not in search of bass that somehow overpowers the music but if the walls shake when something goes down to 35hz, thats kind of cool to me, whatever, but saying that I need the fullness. It does not fill the room as it is right now. I know the power should be there. They are placed right next to the open baffles. I need to experiment more.  Anyway I do not want to really shake anything I just want good bass. My system is moving upstairs above the garage that will be a designated listening room. (in two months?) I want it to sound good where it is now though. I know there are fans of different sub companies, I went with SVS for 65 days or something. I think I might add one more and if I still have a girlfriend I can go from there. Thanks for all the help. Im in the process of reading millercarbons suggested links. 
My system
Parasound A21
Homemade open baffle audio nirvana 10" drivers (backups)
2 SVS 3000
ATA Phono Pre 
VPI with a good cartridge

These sound different and I switch them out sometimes
mytek DAC/pre 
and a
Lumnous audio passive pre

Tannoy Glenair 10" speakers in process of repair



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Big single. Providing its better of course ie faster, more responsive, gets under 30Hz comfortably etc. Always liked this quote found on the REL website,

The great race car designer, Colin Chapman of Lotus was once quoted as saying “To go faster, first add lightness.” Words to live by.

https://rel.net/not-all-cones-are-created-equal/



bryantdrew,

     I'd suggest you state a few more details for best responses:

What's the size of your room?
Are there any irregularities or restrictions in your room?
Carpet or hard floor?
Is your system used just for music, ht or for both?
What does your current system, besides the 2 SVS subs, consist of?
What's your budget?

Thanks,
  Tim


bryantdrew,

     I agree with millercarbon that you'll have much better results adding 3 to have the magic 4 subs in any given room that almost magically provides state of the art perceived bass response in virtually any room.  
     Of course, it only seems like magic once you actually experience the amazing transformation in bass performance in your room when you utilize 4 subs properly positioned in your room rather than 1,2 or 3 subs.  It is actually the opposite of magic since it is all based on the rigors of scientific experimentation, documented results, peer review and the experimental results have been verified independently numerous times by other scientists.
     This proven concept is called a Distributed Bass Array (DBA) system  and it consists of 4 subs strategically positioned in any given room that scientifically (not magically) provides state of the art perceived bass response throughout the entire room and not just at a specific sweet spot.
     I don't know the size of your room, bryantdrew, so I'm not suggesting you deploy 4 large SVS 3000 subs in a DBA system unless your room is huge and you're OK with weakening the structure of your home.  You could attain all the benefits of a custom DBA system in your room by just adding 2 smaller subs of your choice to the 2 larger subs you already have.  
     This concept works so well due to there being at least 4 distributed points (subs) in the room launching bass sound waves into the room.  These 4 subs are actually creating more bass modes in the room (spots where the bass is perceived as exaggerated, attenuated or even absent) but, due to the way our brain processes multiple deep bass sound waves, we perceive the bass in total as smooth and articulate.
      When I setup and listened to my Audio Kinesis Debra 4 sub DBA system in my 23x16 ft. room and initially heard the excellent bass produced, my first thoughts were that it actually did seem like magic how the bass performance in my room/system had been transformed so dramatically.  I know it's all scientifically based but experiencing what I consider sota bass in my room, on my system and on my music still seems magical to me.

Tim 
     
What’s your purpose in uograding, SPL, bass extension, or sound quality? 
 
Also, I know SVS has an upgrade program, but their higher end loses bang for buck due to the digital screen, remote mobile app control, room correction, etc. I mean, if you want those things, it’s great, but from raw performance, a Rythmik F18 smokes the SVS SB-16 Ultra. 
 
Dual subs give a more even response, better seat-to-seat consistency, and lowers localizability.
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You will have much better results adding than subtracting. The problem is none of the conventional approaches addresses the fundamental problem of resonance nodes at low bass frequencies. Two subs are better than one, but three is even better and four is better still. Beyond four continues to improve but the benefit in terms of smooth response falls off rapidly so that four is the sweet spot so to speak.

You're right about it being covered elsewhere. Unfortunately few seem to have bothered to read, or if they've read then to understand. The place to start if you're interested this review explains the what and the why better than most http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/
Then if you want more technical http://www.gedlee.com/Papers/multiple%20subs.pdf
Then of course there are useful threads right here, although with the usual caveat of having to sift through mounds of dirt to mine the occasional gold nugget https://forum.audiogon.com/discussions/will-a-subwoofer-add-depth-and-clarity-to-my-system-or-just-b...

Or you could go straight to the gold itself
https://forum.audiogon.com/users/audiokinesis/posts
Your subs should be capable of shaking s++t. 
How large is your room? Speakers, Amp, etc.?
B
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