Upgrading sub to get a live feel.

Two RELS

@mcreyn, yeah Tim was interesting at first, but now it's gotten pretty old. I am a fan of Duke LeJeune's speakers having owned the Jazz Modules before finding ESL nirvana. So when he developed his Swarm I had always intended to give it a go, until I started working with Roger Modjeski and he convinced me to go down a different path. Either way it would have worked out well.

The active crossover is EQed and my Acoustats have been modified. Of the two panels in each speaker, one is actually Roger's ESL panel. They have also been modified to use the Acoustat direct drive amps. So no interfaces.

Thanks for the tip on the car system and software. I'll look into it further.

mcreyn:
"At the end of the day, it is not about hitting huge SPL levels, it is about getting the best sound, which requires using subs that can stay clean and not run into dynamic compression. 4 10" subs can't do this in a reasonably sized room. It is why my progression of home subs has taken me from Velodyne F series, through ULD's, to HGS, and finally Rythmik. At each step, it has seemed to be amazing (and better than anything I ever heard at a dealer), but the next step revealed more."


Hello mcreyn,
     I'm glad to read your comment that "at the end of the day, it is not about hitting huge SPL levels, it is about getting the best sound, which requires using subs that can stay clean and not run into dynamic compression".  This makes complete sense and I agree with this statement.
     I was questioning whether you had the knowledge and experience to realize the truth in your statement because you were mentioning earlier the ability of larger subs being able to reproduce deep bass at 115 db which is not necessary and can literally cause permanent hearing loss after about 30 seconds.  I wish you had made this statement earlier. 
     Your statement, "it is about getting the best sound, which requires using subs that can stay clean and not run into dynamic compression. 4 10" subs can't do this in a reasonably sized room", I believe also indicates that you have a lack of knowledge and experience of how well the 4-sub DBA concept actually works in any room and with any main speakers.  
     It's definitely true that the four subs in the AK Swarm DBA system are each relatively small (1'x1'x28"), weigh only 44 lbs, contain only a single 10" aluminum long-throw driver and are used in a room considered by most to be reasonably sized (my room is 23'x16'x8').  After using this bass system for almost 5 years now, I know with certainty this system is an excellent performer in the limited 20-50 Hz range that I require supplemental deep bass, my main Magnepan 2.7QR planar-magnetic dipole speakers provide excellent bass performance but only down to about 35Hz but it blends seamlessly with the deeper bass produced by the four Swarm subs that extends bass response of my system down to 20 Hz.
     I completely understand the skepticism from you and other individuals accustomed to utilizing fewer but larger traditional self-amplified subs in their systems.  I understand the lack of comprehension and justified skepticism because I initially lacked the comprehension of how this was possible and was very skeptical myself.  It took me a lot of research on the science behind the DBA concept, reading numerous extremely positive reviews on the AK Swarm and custom DBAs from professional reviewers as well as users and a lot of email and phone conversations with AK's James Romeyn to convince me to give it a try in my room and system.  
     I'm  so glad I did because I consider the bass the 4-sub Swarm DBA system provides in my system/room to be state of the art for both music and HT.  It honestly seems to me like I've learned about an audio secret and I now feel a responsibility to spread the word and let my audio brothers and sisters in on this almost magical secret.
     Of course, I realize the Swarm does not provide the optimum bass response performance that the DBA concept is capable of.  I believe the optimum bass response performance that the DBA concept is capable of would most likely be realized by a combination of our viewpoints, four very large subs with even greater bass extension and output capacity positioned in the room as a distributed bass array system. It's also possible that room correction, either of each sub individually or as a 4-sub group, could further optimize the performance of such a system.   
    I'm currently more than satisfied with the Swarm in my system/room, even though it's performance is a bit less than optimum for a DBA system, due to its combination of extremely good bass performance and its inconspicuousness in my living room.
    In my experience, I can definitely state with validity that the extremely high quality of the Swarm's or a good custom DBA system's bass performance exceeds the sum of its parts.  I'm convinced the factor that's responsible for this is the DBA concept's utilization of psychoacoustic principles that I've explained in detail on an earlier post on this thread. 
     How our brains process the existence of the abundance of bass room modes (many bass peaks and dips) produced by the 3-4 subs in a DBA system by summing and averaging the bass by frequency which results in the perception of the bass as being very accurate,detailed, smooth and natural while also being very flexible to reproduce whatever bass the source content calls for; fast, rhythmic and tight on music or sudden, deep,dynamic,powerful and impactful for music and HT.  

Tim
    

upgrade the Speaker brand.
 don't take that the wrong way  

Clio09,  

Enjoy the 911.  The 84-89 911s were special.  Personally, the 964s always have held my heart.  

Noble100,

It is obvious in your mind there is only one solution to a problem, yours.  Thank goodness people like James B. Lansing, Paul Klipsch, Henry Kloss, Paul Walker, Roy Allison, and Jim Winey didn't decide that the best speakers of their day were as good as could be.  

For virtually every issue in life and science, there are multiple solutions, each with its own trade offs.  Those that get so myopically focused as to believe there is only, or decide they already know it all, never learn and never develop further.   There is no best speaker design, dynamic drivers, horns, electrostatic, ribbon, or quasi ribbon, they all have trade offs.  

You can fool yourself that the only important thing with subwoofers is a smooth frequency response, regardless of output capability, transient response, room decay, phasing, and a plethora of other issues that we are still learning and defining in the setup of sound. 

You can also continue to believe that your 2.7s extend with any authority to 35 hz, they start to roll off in the 50hz range and will quickly slap the panels when trying to reproduce any type of deep bass.  If you would high pass the 2.7s they will sound less dark and sound cleaner after being relieved of trying to handle the deep bass.  Did I mention I owned a pair of 2.7s for more than a decade which were run both full range and with an active crossover?

Just for shits and giggles, I ran a quick MLSSA at my listening position in my main systems this morning.  There are two graphs, the one with bass flat to 20hz is my 3.5s with a single Rythmik 15, crossover set at 80hz between the two, and NO EQUALIZATION.  The second with the rolloff is the 3.5s running full range.  

https://photos.app.goo.gl/rDxsgpnU5xVsz1UWA

@mcreyn --

...

There is something magical that happens when you have that free dynamic headroom. Most home subs suffer from dynamic compression and distortion when turned up. It starts in the 90db range below 30hz for nearly all subs, until you start getting into the big boys. For example, even the Velodyne DD18+, considered a huge, accurate sub, cannot hit more than 110db at 30hz, 105 at 20hz. Same for a Rythmik F18.

When all you have ever heard are subs that are running into dynamic compression and distortion (which is the case with almost all home subs when pushed to even 100db), they sound great, until you hear a setup that doesn’t. When you hear the setup that doesn’t you experience this effortless, fast, tight, bass that seems to come from blackness. It also has a dramatic effect on the sound of the mains, making them sound much cleaner.

At the end of the day, it is not about hitting huge SPL levels, it is about getting the best sound, which requires using subs that can stay clean and not run into dynamic compression. 4 10" subs can’t do this in a reasonably sized room. It is why my progression of home subs has taken me from Velodyne F series, through ULD’s, to HGS, and finally Rythmik. At each step, it has seemed to be amazing (and better than anything I ever heard at a dealer), but the next step revealed more.

Finally, you can rag on those guys at the AVS forums, but unlike many, they spend a lot of time correlating objective data with subjective sound to get improvements.

Sweet music to my ears - well put indeed. While I would gladly recommend a 4-sub approach I’d differ on the oft-promoted stance here on using ~10" woofers for that purpose mostly (that’d be a typical selection of lower fs hifi drivers with a sensitivity no higher than 90dB’s, if that high), direct radiating units at that, and instead - to significantly gain headroom - throw in a bunch of bigger diameter pro-style units - preferably via tapped or front loaded horns or other partially or wholly hidden driver approach from the likes of some 6th order bandpass iterations.

Subs like that though are big, certainly with drivers of at least 15" diameter, so having a quad arrangement of those is a stretch in many if not most domestic environments. Therefore I’d strongly recommend going with a pair of subs, and I’d urge making it a pair instead of only one (i.e.: smoother coverage, and more headroom), although a single sub can be made to integrate very well from a rather narrow seating position, as has been already suggested.

The operative word posed by the OP seems to be that of a sought after "live feeling," and to get that and meet properly with the likely future acquisition of the JBL 4367 mains you have to get the midbass right as well, and for this I wouldn’t go too low in tune (no lower than some 20Hz, but OTOH no higher than 28-30Hz to still qualify as subs), have lots of effective air radiation area, and generally keep sensitivity fairly high (no lower than some 90-95dB’s). This naturally lends one a fair amount of headroom as well, which is an absolutely necessity here when smooth, clean, effortless bass reproduction is required.

Now this is just my preference, one that I actually live by with my choice of subs, and it largely dictates going with a DIY-approach (though I’m aware there are other, pre-assembled solutions to be had that could fulfill the same overall goal as well). A single 15"-loaded tapped horn I’m using, taking up 20 cubic feet per cabinet, will hit ~120dB’s at about 22Hz with approx. 200 watts, and I got a pair of them.. The specific B&C pro driver takes 1000 watts Nominal Power Handling (2-hour pink noise signal), so even pushed to ~600 watts where it reaches Xmech in this Tapped Horn (prior to thermal ditto), dynamic compression will be held at bay at have a pair of those TH’s reach honest 125dB’s over its entire usable bandwidth (20-100Hz) with zero issues, also being that the heavily ventilated driver motor is placed in free air in not inside a more or less closed box, so to be able to shed heat more freely. This bodes well for ample headroom of at least 20dB’s if 105dB’s is the typical upper ceiling for SPL.

And yes, my tapped horns derive from the Avsforum, more specifically a developer who goes by the user-name of "lilmike," and those guys over there are oftentimes rather hardcore with their approach, knowledge and actual sub-implementations.

From a slightly different angle. Depending on the condition and value of the car, with 911s you do not want to deviate so far as to not be able to return the car to stock. Use drivers that fit in the factory locations. Do not cut into or drill any metal. Otherwise have fun. Most 911 guys will tell you that you already have the best sound system going, 6 cylinders screaming away behind the rear axle:)

phusis,

Tapped horns are awesome, make mine a DTS-10.

I am not a big fan of 6th order enclosures, they lean towards a narrow frequency range and have to built perfectly to specification or it all falls apart. For high output with limited space, 6th order enclosures have a place. There is a reason the SPL car guys use them. I did build and use a 4th order bandbass for a car for several years, but that was when power was limited and it gave good output for the space.

@mijostyn, point well taken. Other than the Turbo tie rods and the Bilstein cartridges inside the Boge struts in the back, the car is stock and I intend to keep it that way. I've owned the car for 1/3 of its life. It's not a looker and has over 200,000 miles, but the tech servicing the car keeps it in tip top shape and it's always fun to drive. So now it's time to send it to the spa to get it spruced up a bit.

mcreyn:"You can also continue to believe that your 2.7s extend with any authority to 35 hz, they start to roll off in the 50hz range and will quickly slap the panels when trying to reproduce any type of deep bass. If you would high pass the 2.7s they will sound less dark and sound cleaner after being relieved of trying to handle the deep bass. Did I mention I owned a pair of 2.7s for more than a decade which were run both full range and with an active crossover?
Those that get so myopically focused as to believe there is only, or decide they already know it all, never learn and never develop further."

Hello mcreyn,

      You're likely not aware of how well your 2.7QRs reproduced bass because of the amp or amps you used to drive them. In my experience, they performed better over their entire frequency range with more powerful amps that have high damping factors. 
    The 2.7s are 3-way speakers and actually have a rather large planar-magnetic dipole bass section in each panel (625 sq. inches). I was previously driving mine with an Aragon stereo class AB amp that was rated at 400 watts into the 2.7's 4 ohm load and the bass was decent. Their bass performance noticeably improved when I switched amps to a Class D Audio stereo amp that was rated at 440 watts at 4 ohms and with a damping factor >1,000 and later they produced the best bass I'd ever heard from them when I switched amps again to a pair of D-Sonic class D mono-blocks rated at 1,200 watts each at 4 oms and the same very high damping factors.
    Your statement that "You can also continue to believe that your 2.7s extend with any authority to 35 hz, they start to roll off in the 50hz range and will quickly slap the panels when trying to reproduce any type of deep bass." is definitely and categorically false when the 2.7s are driven by sufficiently powerful amps with very high damping factors. I didn't measure the exact in-room bass extension but, by ear, the 2.7's rated bass extension of 35 Hz seems accurate and there was absolutely zero panel slapping occurring at anytime. I've had that occur on previous Magnepans I've owned and know what that sounds like.
    I think the 2.7's bass by themselves would more than meet the needs and expectations of most, including myself, but it lacked a bit of the visceral bass you feel as well as hear that gives the perception you're listening to live music unless I cranked the volume up to halfway. I don't always like to listen to music that loud so I continued to use the two 12" subs. This worked well but I thought the bass detail, impact, dynamics and blending with the 2.7s could be improved upon.
    I began thinking a pair of more expensive and higher quality subs might improve the performance in these areas but stumbled on the Audio Kinesis Swarm 4-sub DBA concept during my search for a very high quality pair of subs for about $5K or less.  I decided to give the Swarm an in-home free tryout first at $2,800. I think I may have previously mentioned how well the Swarm 4-sub DBA system performed in all the important bass areas in my system.
    You stated: " Those that get so myopically focused as to believe there is only, or decide they already know it all, never learn and never develop further."
    I think my path described above disproves the accusations that I'm myopic, believe there's only one solution, know it all and never develop further. The truth is I was willing to try two different amps of a type I'd never used before, gained practical bass system knowledge and experience by utilizing several different supplemental bass methods in my system such as a single sub, dual subs and even a sophisticated and advanced method using four subs strategically positioned and configured. Now that I've thought and written about some of my audio journey,  I know that none of your descriptions apply and the more fitting description would be open-minded, willing and daring enough to try various methods and gear to gain knowledge and experience. Perhaps I should change my user name to audioadventurer.
     Finally, you stated " If you would high pass the 2.7s they will sound less dark and sound cleaner after being relieved of trying to handle the deep bass. Did I mention I owned a pair of 2.7s for more than a decade which were run both full range and with an active crossover?"
    Were they black and did you sell them to a guy from Indiana that met you in a parking lot in Dayton, Ohio for the $1,200 transaction?  If so, that was me.  Hah!, that would be unbelievable.   Maybe you'd have kept them if you had a better matched amp or amps to drive them.
     I did try running the 2.7s high pass filtered through the Swarm's amp/control unit, trying various crossover settings between 100 and 230 Hz and was expecting the 2.7's to benefit.  I believe I didn't get the typical sound quality gains from high passing the mains because my D-Sonic mono-block amps, at 1,200 watts each, were not overtaxed driving the 2.7s full-range. 


Later,
Tim

Clio09, any 911 can be a valuable car as long as it has not been wreck, is not rusting and has not been modified. You want to use the factory mounting points for speakers and electronics that fit in the factory space. Outboard woofer enclosures are fine. No cutting or drilling metal! If the car is a renegade then the sky is the limit.

Excuse me for the last post. I'm on some pretty heavy drugs right now and my mind is stuttering. The tie rods and struts can always be returned to stock. When was the last engine rebuild? You can always make it a looker again if you put the money into it but for a fun driver you just have to keep up with the basic stuff. 911s from 78 on are all galvanized so you really don't have to worry about the paint that much. It is just an aesthetic thing. The external rubber parts can get pretty moldy if the car was parked in the sun. They are easy to replace with modern rubber. Good that you have an indie you can trust. Not easy to find. Thing about 911s is you can make them go forever:) 

@mijostyn, what engine rebuild, lol, 208k miles (112k with me) and not even a recommendation of a valve job on the horizon (has had a transmission rebuild though). The clear coat is flaking off the trunk lid due to some foreign substance that dripped on it while I had it parked at SFO during a business trip, but other than that I just need to wash it more, lol. Interior is very presentable other than the typical dash cracks and the AC stopped working years ago. Don't really need it around here though. Most techs rave about the 3.2L engines as being among the best Porsche ever made (my tech has a car out there with 450k and one valve job on it). Sure the '68-'73 series looked sexier, but the '84-'89 series cars were always being recommended to me when I looked for a replacement for my '72 Targa.

lol, this thread is way off topic now, but I got my subs so lets play.

I listen on average between 90-95db.

The PB-1000 is significantly larger in size than the SB-1000.

The room size is 16x30. The speakers are placed on the 16 side, and I sit about 11 feet away from the speakers. The SB are located right under the main,  6" from the wall.

The SB-1000 are set to about 65Hz to blend, zero phase, 60% volume. I’ve always found very clean and articulate bass at this current settings, and anytime I’ve made an adjustment, I’ve dialed it back to these.

First test just running one additional sub (3), placed on the left side besides my seat, set at 60Hz, played with gain to peak bass, and 60% volume. The biggest difference is an increased amount of headroom, the speakers felt slightly larger. It blends well in this position, but you can feel the physical bass being directional. That feeling makes you slightly detract from listening.

Second test, quad sub, placed along side seating position against the wall. Similar settings, but with 45% volume, because the wall gives it a boost. I get a nice spacial balance, but I could not get them to blend in this position. At those settings, I got a bit of harshness in the low regions.

I finish the evening with using one additional sub, as I got tired, and just wanted to listen to music.

I think I have to lower the crossover point when running dual tonight, and see how that goes. 

Have you tried a more asymmetrical positioning with the two extra subs. IOW place a couple behind your speakers along the front wall, then the other two should be place along the side walls, but not symmetrical, stagger them. I have also seen arrangements recommended where the subs are place along the front and back wall. I think someone may have linked to the article in this thread. You also have the challenge of setting the volume level of the subs optimally. There are better experts on this thread than I to advise on that. Keep playing with it though, you will eventually getting it dialed in.

I just checked the OP's posts and he hasn't mentioned the size of the room, unless I missed it, or someone else correctly guessed it in one of the many verbose other posts.  The cubic footage is crucial.  Also, the shape of the room ( L shape??), whether there are arched ceilings, carpeted vs laminate, etc, is all worth considering.

The OP's current speakers retail for $4000, and he's considering replacing them with $14000 speakers.  First of all, I am puzzled why either of his current subs, scraping the bottom of the budget barrel at around $500 each, would be considered a good match for the current speakers, let alone the possible upgrades.

Second, sealed subs generally have a different sound than ported subs, and are considered more musical than the ported designs.  As you go up the budget, ported designs get better, but at the $500 level, too many compromises occur.  And only 300 watts?  Yeah.

You'll think this sounds ridiculous,but it costs nothing to experiment.Turn the subs behind your listening position to face the wall.Clio is right about trying them in various positions.All four of mine are positioned facing the walls.It is a pain to fine tune the positions and crossovers  x 4.I worked on mine for a couple of hours at a time maybe every three days or so to keep myself from getting OCD over it:)

thewatcher101:

The room size is 16x30. The speakers are placed on the 16 side, and I sit about 11 feet away from the speakers. The SB are located right under the main, 6" from the wall.

I'm reading this as your main speakers are 6" from the wall??? Can't be right.

Subs right under, or even real close to the mains is another problem. Some might think this is necessary for timing or whatever. Do a little research. Timing is not a factor with low bass.

Instead what you want is exactly the opposite of timing: a lot of randomly spaced sources. Putting subs close to mains is by duplicating the location robbing you of a lot of the improvement you'd otherwise be getting. Move em.

The SB-1000 are set to about 65Hz to blend, zero phase, 60% volume. I’ve always found very clean and articulate bass at this current settings, and anytime I’ve made an adjustment, I’ve dialed it back to these.

Easily the biggest problem or pitfall with subs is trying to hear them working. When done right you don't hear them at all. No one listening to my system will have any idea there are 5 subs. No one will have any idea there are ANY subs! They certainly will have no idea there are two way back off to either side and behind them. 

My first big mistake in setting these up was getting the levels way too high. Its hard because a lot of recordings have no really low bass to speak of. So its real easy to wind up with too high levels because you used the wrong recording.

Test tones and meters aren't much help either. This is because the way us humans hear really low bass changes depending on volume. See Fletcher-Munson curves. Because of all this what I find works best is just relax, listen to a lot of music at whatever volume levels you like, and don't try and get it dialed in too fast. Be patient, make very small tweaks, and don't try and make any one recording sound perfect.

First test just running one additional sub (3), placed on the left side besides my seat, set at 60Hz, played with gain to peak bass, and 60% volume. The biggest difference is an increased amount of headroom, the speakers felt slightly larger.

Yes. "The biggest difference is an increased amount of headroom, the speakers felt slightly larger." Exactly! 

The bass that comes from adding more subs is completely different than the bass that comes from adding a bigger sub. The difference is exactly what you said, the speakers sound "bigger". 

The thing about really low bass, the frequencies are 40, 80 feet or more in wavelength. Because low bass has such a long wavelength the only places you really hear them are in huge auditoriums or concert halls. Walk into any huge space like that you can tell its a huge space even with your eyes closed. Because of the fundamental low bass resonance. You feel it. It tells you you're enveloped in a vast space.

Now with one or two subs, even really good ones, the low bass reflects and cancels and really cannot truly exist. So you never get this feeling of envelopment. With three or more subs though at some point there are enough extra sources to overcome the cancellations and the really low bass is believably there and you do get this sense of envelopment. This is what is making your speakers sound "bigger".

 It blends well in this position, but you can feel the physical bass being directional. That feeling makes you slightly detract from listening.

Not sure what you're doing. The only time I ever was able to localize a sub the crossover was way too high. Set properly all my bass is incredibly, ubelievably precise and localizable. The bass. Not the speakers. 

Now sometimes the bass on the recording just happens to be coming from where there's a sub. This happened a couple times and bugged me until I realized its not the sub, its the recording. Patience.

Second test, quad sub, placed along side seating position against the wall. Similar settings, but with 45% volume, because the wall gives it a boost. I get a nice spacial balance, but I could not get them to blend in this position. At those settings, I got a bit of harshness in the low regions.

Probably this is just too much bass. Every additional sub adds both extension and headroom- and volume. Adding a sub requires turning down the level on all the subs.

16 x 30 is the room size.

I prefer sealed subs, but the Audiokinesis Swarm was designed as ported, with the option to seal the port with a plug. The set up used by the designer has the woofers facing the wall as jtcf mentioned. When I used a Swarm like set up I had woofers facing into the room and towards the wall. Even had one next to the listening seat and anyone who came over for a listen, including a friend who designs and sells speakers, couldn't hear any of the subs. He had to ask where the 4th sub was located and when I told him to look over the side of the arm rest he chuckled when he spotted the sub.

In my set up now the two front woofers face each other along the front wall, the other two woofers are next to the speakers and face out into the room per a method recommended by mijostyn who has posted on this thread and other sub threads. Both methods work well for me, but given the type of speakers (line array) I am using now the newer method has resulted in increased bass response and more 3D imaging. If I go back to point source speakers I will go back to an asymmetrical arrangement.

They are 6 inches away from the wall, and I'll turn everything down and see how it goes. 

When the SB were originally set up they added additional headroom to the speakers, without being heard were my standards. 

This has been a great thread,  Not too long ago I added a second REL T5 to my Omega Super Alnico Monitors, and things have been sounding really great (16 x 26 room with 8 ft ceiling and open on two sides).  Since reading about the Swarm package and various threads about setting up a dba, I’ve been interested in adding a third subwoofer next, and eventually a 4th.  The question I have is this:  would I get better better bass improvement adding a 3rd T5, which has a single sealed 8-inch driver, or try to get a larger (10 or 12 inch) sub for the third sub? The current subs are run in stereo.  As the new sub would be run off both channels, would I need to reconfigure the others to also run off both channels, or should keep them in stereo.

Hello ihor,

     I would suggest running all three subs in mono and adding a larger 10 or 12 inch sub for your third sub would be the best choices.  
     There are virtually no current or past music recordings in any format (vinyl, cd or hi-rez files) that contain stereo deep bass, all of the bass below about 80-100 Hz is summed to mono on the recordings since humans are unable to localize (tell exactly where the bass is coming from) on bass tones below about 80-100 Hz.
     Even though all three subs are outputting mono bass, you'll perceive the bass as a form of stereo bass, with the sound seeming to come from the proper bass instruments within the soundstage illusion ( for example, the drums are located in the center rear of the soundstage and the upright acoustic bass is located in front of the drums and off to the left.). 

      This is because, even though the fundamental deep bass tones below about 80-100 Hz coming from the subs will not be able to be localized, the related bass harmonics or overtones of the fundamental bass tones coming from the main speakers are able to be localized (since they extend above the 80-100 Hz limit).  Our brains are able to associate the higher frequency bass harmonics/overtones with the much lower frequency bass fundamental tones and thereby determine where the much deeper fundamental bass tones are originating from. This process is one of the principles of he science of psychoacoustics (how our brains process sounds and form perceptions).
      Having a larger 10 or 12 inch sub as the third sub also relies on psychoacoustics and will give the perception that the overall in-room deep bass response has been extended a bit deeper.  
     Proper positioning within your room and the proper setting of the volume, crossover frequency and phase control of each sub are very important for optimizing bass output in your room and integration with your main speakers.

Tim

Tim, thanks for your response.  This makes sense.  Looking forward to pursuing this dba!  The positioning and setting crossovers, phases, and volume will be the ultimate task and key to success.

Hello ihor,

     Cool, it's a bit difficult to put into words and I'm glad you understood.  I can help you with the positioning and proper setting of the volume, crossover frequencies and phase controls when you get your third sub. Just send me a personal message or post again on this thread when you're ready.

Tim

@mcreyn --

phusis,

Tapped horns are awesome, make mine a DTS-10.

They are indeed, but few know of this - certainly outside the Avsforum and similar-ish sites where bass performance is explored rather uninhibitedly. Tapped Horns are bandwidth limited in their upper range (depending on the tune), and one needs to know what he/she is dealing with and the specific context in which they’re to be implemented to make the most of them. Once you do, and accept size is inescapable, it’s obvious bass isn’t just bass - irrespective of the configuration.

The DTS-10 is a beast. I’d give up a few Hz in the bottom end and go with the TH-50 instead (or even a few Hz more to favor Josh Ricci’s B&C 21"-fitted Othorn), but that’s just me ;) My own MicroWrecker’s are very much influenced by the TH-50, with a tune in the same ballpark as well.

I am not a big fan of 6th order enclosures, they lean towards a narrow frequency range and have to built perfectly to specification or it all falls apart. For high output with limited space, 6th order enclosures have a place. There is a reason the SPL car guys use them. I did build and use a 4th order bandbass for a car for several years, but that was when power was limited and it gave good output for the space.

Sorry I wasn’t clear on this, but I had Josh Ricci’s Skhorn and Skrams in mind when I made mentioned of the 6th order bandpass iterations, rather than making a generalized statement. Otherwise I take it you are absolutely right in your observations, apart from pointing out that Ricci’s designs here are actually less bandwidth limited in the upper end compared to tapped horns.

I wouldn’t mention any of the sub designs brought about here (in pairs, preferably, with more of them being a bonus if space permits) if I didn’t believe they’d be potentially excellent combos with the OP’s future main speaker consideration. Properly implemented he’d have at least 25Hz honest extension and a totally effortless, smooth and "live" bass with proper energy in the midbass. 

I’d stress that this is about acquiring the best possible bass response and integration, and that a vital part of this is attained via ample headroom (from great sub designs) to sport extremely low THD, even at "full chat." Headroom is hugely important; to have the SPL capacity way beyond what one needs, as it both relaxes and empowers the presentation.

Got a few more hours in last night, 

Sub set up is now staggered, with one PB against the wall distance between speaker and seating position, one PB a little behind the seating position. 

Turned down the PBs to 50Hz and volume set to 30%. 

The speaker still feel larger, but less so now. 

Bass blends well at this point, but i am still experiencing a tiny bit of harshness in the music. Noticeable in the lower-mid/upper bass regions.  It lacks the cohesiveness of my original set up.   

I think this evening I will try to turn down the SB too and see if that helps. 

Hello Watcher,

     Sorry about mcreyn and phusis having a discussion on the benefits of horn tapped subs in the middle of your thread.  I just found out they're both longtime members of the Church of Latter Day Bass. A little rude but no big deal.
     I'm going to give you a step by step procedure for how to position each of the four subs and set the controls on each very soon but I need to know a few things before we get started to make sure we have everything we'll need:

1. What are the brand and model numbers of your other components?  I need to know whether you're using an AV receiver, integrated amp or preamp and power amp setup.

2. How do you currently have both of your SB-1000s connected? I need to know what method, line level or speaker level connections, you currently use and how you planned to connect all four subs.  If you don't already have a plan, I'll figure it out but it may require you buying a few things before we can begin.

3.  Are your JBL 4319 main speakers positioned on the floor, on stands or a different method?

    Depending on your other components, mainly your amp, we need to determine whether you should limit the bass reproduced or run them full range. W'll pick backup once you give me your answers to my 


Tim

1. What are the brand and model numbers of your other components? I need to know whether you're using an AV receiver, integrated amp or preamp and power amp setup.

Resonessence Mirus DAC > Pathos Atrium Preamp > Odyssey Kismet Mono-Block
 
2. How do you currently have both of your SB-1000s connected? I need to know what method, line level or speaker level connections, you currently use and how you planned to connect all four subs. If you don't already have a plan, I'll figure it out but it may require you buying a few things before we can begin.

SB are connected using speaker level input, the PB are tapping the speaker level from the SB. 

3. Are your JBL 4319 main speakers positioned on the floor, on stands or a different method?

The speaker currently sit on top of the SB 

The amp has pretty big bass, the DAC also has very detailed and articulated bass, the preamp is neutral. 

Sorry about mcreyn and phusis having a discussion on the benefits of horn tapped subs in the middle of your thread. I just found out they're both longtime members of the Church of Latter Day Bass. A little rude but no big deal.

"Church of Latter Day Bass" - good one, thanks for the early night (local time) chuckle here. 

Tim, being you're a rather frequent collaborator and advocate of a "four-and-only" sub approach many of us know all too well by now - one that certainly has its merits (and one I don't necessarily disapprove of per se) - it would nonetheless only seem prudent, in a effort to diversify the subject a bit, to throw in an alternative bass-augmentation dish, so to speak; one, or in essence most everything else you'd obviously not approve of. 

Truth be told I'm not on a mission to willfully oppose your views, but simply to recommend what I feel would be one heck of subwoofer pairing with a future main speaker acquisition the OP appears to have in mind. But you don't want to hear that, right? You're all over the place with your "my (sub-)way or the highway," and when a couple of guys have a few challenging thoughts on the matter you're choking on your morning smoothie. 

I'd actually let poster @mcreyn get off the hook here as he simply sided with my fondness for tapped horns, apart from delivering some very worthwhile info.

thewatcher101

They are 6 inches away from the wall,

You keep mentioning hardness in the lower midrange. This right here could be the reason. We all have room constraints so maybe this is forced, but if its not then you might want to try moving the speakers in a few feet from the side walls. 

Being so close to a side wall the critical first reflection arrives within a millisecond or so, well within the roughly 4 milliseconds within which the human ear perceives sound to be coming from the same source. What this means in plain English, its smearing and ruining your imaging.

But that's not all. That's so close the wall is practically acting like a horn, reflecting and reinforcing the speaker but not in a good way. I could never understand your comment trying to link sub placement with this low midrange hardness. Can't see it happening. What I can see happening though is the bass changes distract from hearing the reflection problem that is there all the time. Move the speakers and see.

While you're at it get them off the subs. You'll get better bass and improve imaging in one fell swoop.

phusis: "Truth be told I’m not on a mission to willfully oppose your views, but simply to recommend what I feel would be one heck of subwoofer pairing with a future main speaker acquisition the OP appears to have in mind. But you don’t want to hear that, right? You’re all over the place with your "my (sub-)way or the highway," and when a couple of guys have a few challenging thoughts on the matter you’re choking on your morning smoothie."

Hello phusis,
If I recall correctly, I stated that the interjection between you and mcreyn was no big deal and I meant it. I welcome new ideas, new information and actually found your discussion of horn tapping subs very interesting, thank you. My intent was not to dismiss or reject the idea of a different solution for watcher, I just thought, since he already committed to trying the 4-sub DBA concept by buying two more SVS subs, he should first give that concept a fair try before being asked to consider a solution that would be much more expensive and require utilizing much larger subs.
You are correct, I am an advocate of 4-sub DBA systems and I understand many likely prefer I’d just stop already. I think it’s an excellent solution for anyone who has the funds and room space. However, I’m not naïve or ignorant enough to think it’s the only or even the best solution. I understand each individual situation deserves an individual and unique solution based on the specific circumstances and preferences. I believe the best solution for a given individual system and room can span from a single sub or dual sub setup to a 3+ sub linear or distributed bass array setup to more elaborate and larger sub bass systems utilizing horn tapping or even larger horn based subs to something new or that I’ve never even heard of.
You stated "But you don’t want to hear that, right? You’re all over the place with your "my (sub-)way or the highway," and when a couple of guys have a few challenging thoughts on the matter you’re choking on your morning smoothie."
Wrong, I want to hear your discussion with mcreyn and all sorts of opinions, information and ideas from you guys or anyone else willing to share them. Who knows, I may even feel the urge to share some, too.


Later,
Tim

@thewatcher101, how do you like your Resonessence Mirus DAC? Ironically Resonessence shared a room with Audiokinesis at the Long Beach Audio Show where Duke from Audiokinesis was showing off his new two-way hybrid horns and Swarm array. Also ironically Duke set his monitors on top of two of the woofer boxes. I thought the room sounded decent Friday morning but by the afternoon it was sounding really good. Duke's rooms are generally among the best in sound at shows I have attended.

watcher,

Okay, speaker level connections should work well and daisy-chaining from one sub to the next is convenient, too.
When I positioned my four subs, I decided to just follow the suggested procedure and locate the subs to optimize the bass performance in my 23x16x8 foot room that serves as a living/music/HT room. My audio equipment, tv and main speakers are along a 16’ wall with my listening chair about 12’ back from the center of this 16’ wall. I decided my wife and I could then do any necessary furniture rearrangement afterward. Here’s the procedure, based on the ’crawl’ method, that I used to position each of my four subs:

1. Power down system, disconnect speaker wires from main speakers and remove them from the room.

2. Connect Sub#1, power up system, set sub#1’s volume to 50%, crossover frequency to 65 Hz with the phase set at in-phase (’0’) and place it on its back (driver facing the ceiling) at the normal listening position. Play music that has good and repetitive bass.

3. Walk slowly along the perimeter walls of the room, starting at the front right corner of the room and moving in a counter-clockwise direction, listening for the exact spot that the bass sounds best to you; not exaggerated, attenuated or missing bass but detailed, solid, smooth accurate and natural bass. Walk slowly enough and you’ll definitely notice the exact spot it sounds best.

4. Place Sub#1 at the exact position you determined the bass sounded best to you.

5. Connect Sub#2, set sub#2’s volume to 50%, crossover frequency to 65 Hz with the phase set at in-phase (’0’) and place it on its back (driver facing the ceiling) at the normal listening position. Play music again that has good and repetitive bass.

6. Continue to walk slowly along the perimeter walls of the room, starting now at Sub#1 and continue moving in a counter-clockwise direction, listening for the next exact spot that the bass sounds best to you.

7. Place Sub#2 at the exact position you determined the bass sounded best to you.

8. Repeat this procedure for Sub# 3 & 4.

9. Replay the same music with good and repetitive bass, sit in the designated listening seat and verify the bass does not sound exaggerated, attenuated or missing and that the bass does sound detailed, solid, smooth, accurate and natural.

10. If it does not, repeat steps 1-9. If it does, reinstall your JBL speakers, ideally on the floor or on custom stands and about 3-4’ away from the front 16’ wall. Obtain an assistant and proceed to the 4-sub Custom DBA Configuration and Seamless Main Speakers Integration Procedures.

Following this procedure in my room with the Swarm subs, it resulted in two subs located along the front 16’ wall, with sub#1 located 2’ away from the right corner and sub#2 located 2’ away from the left corner. The other two subs sounded best toward the rear of my room with sub#3 along the left 23’ wall and sub#4 along the right 23’ wall, both about 2’ away from the nearest rear corners formed by the 16’ rear wall.

I’m not suggesting you save some time by just positioning yours like mine. I’m suggesting that you follow the same subs positioning procedure and that your subs are likely to sound best in a similar distribution pattern. Your room is the same 16’ width and rectangular shape as mine but it’s 7’ longer and I’m uncertain if your ceiling height is similar to my 8’ ceiling. In any case, there are enough differences that your subs may sound best in somewhat different positions; perhaps with only one sub along the front 16’ wall and the remaining subs in different positions along your 30’ side walls and even one or more along your rear 16’ wall.

I’m just not sure where they’ll ultimately be positioned for best performance. I suggest you just trust and follow the procedure, position each in sequence exactly where it sounds best and everything will probably work out fine.

I was also mentioning the overall distribution pattern of my four subs to give you an example to plan how you’d be wiring and connecting your four subs. I think the speaker level connections and daisy-chaining capability will work well. You just need to determine exactly how you’d prefer to distribute the two shorter SB subs and two taller PB subs. Unfortunately, I have a lack of knowledge and experience concerning how best to deploy two sealed subs (with rated bass extension down to 24 Hz) and two ported subs (with rated bass extension down to 19 Hz) for best overall performance. Theoretically, I believe it should not make a significant difference but you’re the only scientist among us that’s currently capable of carrying out the required scientific experiments to obtain the empirical but very personal and subjective results. If you have a preference doctor, even if it’s based on the trivial idea of having the taller PB subs being located in certain areas near the seating and doubling as end tables, I’d suggest that’s a good layout variable to begin your experimentation with.

I also strongly suggest you invest in a good pair of speaker stands for your JBL 4319 main speakers and positioning them at least 2-4 feet away from the 16’ wall behind them. You can thank me later and I saw several suitable pairs starting at $85 by searching for "speaker stands" on eBay.

I’ll post the 4-sub Custom DBA Configuration and Seamless Main Speakers Integration Procedures once you complete the subs positioning phase of this project.

Later,

Tim

Will be trying, 

As to the  Mirus DAC, after trying a few DAC, it is an exhausting process and not fun to try a bunch of them, at lease not for me. The MIRUS was the most uncolored and accurate DAC, but watch out for USB source, as USB has inherent audio issues. I used iso regen and their LPS, and it solved the usb problem. 

I also have a demo tomorrow with the JBL 4367. 

@thewatcher101 —

Please let us know what you think of the JBL 4367’s once you’ve auditioned them. I’d certainly be very interested to learn of your impressions.. 

I have a dual purpose main system using different amplification for pure audio vs. video, and use a pair of Hsu  VTF-15H MK2 powered subs for video only.

I have run the subs with the audio front end on occasion and they are very good indeed, not just for bass reinforcement with video. Note that they were installed using proper analytic instrumentation for location, configuration and tuning and not everyone has that available - if you just stick them wherever they fit in your room, YMMV.

wspohn:
"I have run the subs with the audio front end on occasion and they are very good indeed, not just for bass reinforcement with video. Note that they were installed using proper analytic instrumentation for location, configuration and tuning and not everyone has that available - if you just stick them wherever they fit in your room, YMMV."

Hello wspohn,

    Just to clarify for thread readers and prevent them from being discouraged or misled about incorporating one or two subs in their systems, I thought it was important to let them know the following about your post:

    While you're absolutely correct in stating that you can't expect to just stick one or two subs in your room wherever they fit in the room and expect to obtain good bass response, it's absolutely not true that they need to be installed using proper analytic instrumentation for location, configuration and tuning and not everyone has that available.
    Everybody has what's required, two ears and what's in between, and knowledge of the 'crawl method of sub positioning' to incorporate one or two subs in their system. Thread readers can refer to my previous posts on this thread or google "the crawl method of sub positioning" to learn more on the specifics of using this method.
    Your use of the abbreviation YMMV can also be misleading since their mileage will not vary. The science of Acoustics has established how the longer bass soundwaves behave in any room and this knowledge is baked into the concept and effectiveness of the 'crawl method'.
  The single most significant rationale for utilizing the 'crawl method', as an alternative to the more expensive and complicated method using analytic instrumentation, is precisely because your mileage will not vary and it can be relied upon to be just as effective in any room or system.
  I'm not claiming any of the above possibly misleading or discouraging language in your post was your intent, I just wanted to make sure a few points were clearly understood by thread readers and potential sub users.


Tim  
 

Right. As an example of just how well this DBA approach works, when my four were first installed all I did was plop them down facing the walls each one a little different distance from the corners. Instantly and without any adjustment the bass was deeper, smoother, faster and more articulate and dimensional in terms of imaging than anything I ever heard before. They have since then been tweaked down in level both dB and crossover frequency, and phase, all of it done by ear because even though I have a dB meter handy its the ears that rule.

Especially with bass. A lot of the problems people have getting this concept seem to have their roots in some really fundamental misunderstandings about how human beings hear and perceive different frequencies. We simply do not register timing with bass, for example, anywhere near the way we do higher midrange and treble frequencies.

In terms of level, meters and EQ fail to account for the way we hear bass volume. Look up Fletcher Munson curves. These graphs are not flat because unlike meters human beings do not respond to bass equally. The way we hear bass varies by volume. A lot. Look at the curves!

So as cool as it sounds and as much street cred as it might seem to get using EQ or meters or whatever other analytical doo dads one might buy, the truth is these things are more often than not used by people who don’t understand everything that is going on nearly as well as they think they do.

Go and listen. You will see.

millercarbon:
"Especially with bass. A lot of the problems people have getting this concept seem to have their roots in some really fundamental misunderstandings about how human beings hear and perceive different frequencies. We simply do not register timing with bass, for example, anywhere near the way we do higher midrange and treble frequencies."


Hello millercarbon,

     Yes, very good points about how we perceive bass sounds differently than higher frequency sounds.  
     We don't even perceive the existence of a deep bass tone sound in a room until the full cycle bass soundwave(a 20 Hz bass tone has a soundwave that's about 56' long) has been reproduced in the room, our ears have inputted the presence of a detected full cycle bass soundwave to the brain and our brain has processed this information as a perceived bass tone.  Any partial soundwave (less than a full cycle bass soundwave) presence detected and inputted to the brain is not processed as a perceived bass tone or any sound at all.
     Our brains also require the detection of multiple full cycle deep bass (below 80 Hz) soundwaves in the room to perceive a change in volume or pitch.  
     Another poorly understood aspect about how our brains process deep bass soundwaves below 80 Hz is the whole subject of psychoacoustics that come into play beginning with use of two subs and the main reason the 3-4 sub DBA concept works so incredibly well.


Later,


  


  
     

  

    

I was able to get the system to work and sounding good, that I didn’t want to mess with it for the evening. The solutions were I didn’t need to move any of the current front set up, they sounded great as they were, the JBL were made to not interact with the environment as much as other speakers, but I might be tempted in the future to move them. Two things that solve the lower mid range harshness was lowering the front subs crossover point to even lower. Bass response and imaging improved with the two new PB using the crawl method. They ended up behind the main seating position against the wall.

The SB front are set at 60Hz and the PB are set at 50 Hz
SB volume is at 50% and the PB volume is set at 35%.
Phase for all 4 is at 0.

Since it is all set now, i’ll play with the crossover points maybe a little more until I get the cleanest imaging.

Then I’ll try to push the volume up a little.

The results are larger sounding speakers, I went in with the expectation of wanting subs that created a lot of energy, if you’ve been to a proper set up room with big subs, you know how that feels. What I got from this set up was just larger speakers that are very accurate, detailed, and enhanced sense of space. It isn’t like a big game changer, but if you have a great sound going and want that extra headroom, this is a wonderful solution. It is a good incremental improvement for a very reasonable price, but I also got more value recapping the speakers. I also have a feeling that if you already have powerful speakers bass like B&W 8xx, this set up with small subs might not keep up. JBL have a very neutral bass and this fits.


As for demoing the 4367, I cannot say I can give a proper review of it. The place I went to had it set up for home theater, at 175watt per channel. The mids and bass were non existent. But to what I can hear. The 4367 have the JBL sound but just in large size. If you like the JBL presentation of music, the 4367 does them. The highs are extended and non fatiguing. I also can’t say it made me want to upgrade, as my current system sounds significantly better than what I heard, but it wasn’t a fair match. I can tell if the 4367 were done properly it would sound like what I have, but just bigger. Maybe when I have the itch to go larger, i’ll scratch, for now I am happy. I like JBL for their sound, I thought I could get significantly better sound as you go up, but the price to performance was not there. 

Hello Watcher,

Sorry about the side-tracks. Back to your system.

I'm glad you used the crawl method and discovered your system sounds good with the PB subs located along your back wall. I believe you’ll notice significant overall system performance by addressing the front of your system and the positioning of your two SB subs.
I suggest you try abandoning using the SBs as speaker stands for your 4319s. For best results, I think you need to treat your system as two systems, a bass system and an everything else system.
The bass system you set up first by properly positioning your 4 subs for optimum bass performance in your room. This provides the solid bass foundation for your system and most music. Its ultimate effect, after your 4319s are seamlessly added as part of your everything else system, will be to make the 4319s sound like much bigger and higher quality speakers.
You need to temporarily move your 4319s out of the room. Set all subs at 50% volume, crossovers at 50 Hz and phases at zero ’0’ for this step. Then utilize the crawl method I described earlier for optimally positioning both of your SB subs in your room, which will probably be along your front 16’ wall but not necessarily. Just locate each where the bass sounds best and trust the procedure. The goal is solely to optimize the bass in your room at this stage, so take your time and get the bass sounding the best you can to you.
Your four subs now form a completely separate and independent bass system that serves as the solid foundation for the rest of your overall system. The everything else system, consisting of your 4319s properly positioned in relation to your listening seat, is also a completely separate and independent midrange and treble system that’s going to be laid on top of your solid bass foundation.
The goal in this phase is to optimize the midrange, treble and the stereo soundstage illusion created by your 4319s at your listening seat. I strongly recommend you invest in a good pair of speaker stands for your 4319s to get the midrange and treble drivers up to the height of your ears when you’re seated at your designated listening seat and to position the 4319s on stands at least 2’ away from the 16’ wall behind them. You’ll notice that, the more you move them away from the front wall, the deeper and more 3 dimensional the stereo soundstage illusion will become. 2’ out will be good but further will be increasingly better.

I think it best we pause here until you’re able to receive a good pair of speaker stands that I believe are very important for best results. In the meantime, you could just position your 4319s on the floor, not ideal but better than nothing.
Also in this meantime, I’ll write up a procedure for the final stage of properly positioning of your 4319s and how to best adjust the volume, crossover frequency and phase controls on your subs for the seamless blending or integration of your two systems.

Is this all acceptable to you? Let me know.

Later,
Tim

Yes, thanks Tim. 

Hello Watcher,

     Great, just so we're on the same page you need to:
1. Complete your bass system by positioning your two SBs using the crawl system.

2. Order a pair of speaker stands for your JBL 4319s. I think the best place to search is eBay and google, just search for "speaker stands for  JBL 4319 speakers" on either.  You'll probably get even better deals on them if you'll accept used ones in good condition.  
     The exact height of the stands is very important.  You should measure A. the distance from the floor to the middle of your ears when seated at your listening seat. Then measure B. the distance from the bottom of one of your 4319s to the middle of the tweeter.  Take measurement A and subtract measurement B and you'll have the exact height required for the height of your speaker stands.  
     My assignment is writing a procedure for you on how to properly position your 4319s in relation to your listening seat and how to best adjust the volume, crossover frequency and phase controls on your subs for the seamless blending or integration of your two systems. 
     Just a heads-up, when you receive the speaker stands and it's time to follow the procedures, things will be easier if you can recruit an assistant to help you out.  Without an assistant, you'll be going back and forth way too many times between your listening seat and each sub and you'll probably wind up exhausted by the time you're done. 
     Send me a pm or post again when you order the speaker stands.

Thanks,
  Tim
    

I already have some speaker stands I can use and the current set up has the tweeter aligned to ear level.

Hello Watcher,

     Excellent, I'll try to complete the procedures today.  

Later,
Tim

I’m going to come at this issue from a different perspective. Fully agree with comments about deep bass being omnidirectional (or non-directional) in most settings. One failing of most audio bass setups (full range or subs), to me, is lack of control. It is relatively easy to get the tone of the bass notes pretty OK. But getting tight control of large woofer excursions is another. How often do people actually hear the timbre of the instruments producing the bass in their systems? One approach to sub-bass control is to throw mega-watts of power at it, probably better conceived as providing max feasible current to drive big bass flappers. Another, more elegant, approach is to employ motional-feedback in the bass amp circuitry. In this schema, the bass amp incorporates circuitry that senses the back-EMF produced by woofer coils when distortion begins to occur then, near-instantaneously, alters the output signal to correct and cancel said distortion. Audible result is to tighten up the bass output which, in turns, makes the woofer emit a sound that more faithfully replicates the original waveform captured in the recording. Loose, flabby bass is eliminated. Some self-powered subs employ this method. The old (1970’s) Phillips motional feedback speakers (full range self-powered bookshelf speakers) also did this with impressive results. In my system, I use one channel of a Streets 950 power amp w/ only 110wpc --equipped with an extra binding post for use when motional feedback is desired-- to drive a single Clark Contra Bass sub (2 x 12" cones wired out-of-phase and bolted face-to-face, downfiring), to produce deep bass in a smallish room that outperforms anything I have heard in a showroom anywhere. The Clark actually sits next to my listening seat. No one can tell the bass is coming from 2 feet away to one side.
One more thing helps with tight sub-bass control. Minimize speaker cable impedance. A long-ago TAS article introduced me to #4 welding wire. Thick, black, fugly, but cheap & flexible & all to terminate with big copper spade lugs. Works. ’Nuff said.

Hello watcher,

      You stated your room size is 16x30. The speakers are placed on the 16' side, and you sit about 11 feet away from the speakers. The SB are located right under the main, 6" from the wall.
    Instead of specific procedures on steps to take, I decided to just generally discuss the important areas of concern and the variables you're able to control. I'll provide specific procedures only when the areas of concern allow such specificity.

1. The Optimum Positioning of your 4319s:
    I went to the Cardas website linked below and read their suggestions for positioning a pair of stereo speakers in a rectangular room. I'm less confident on these suggestions than I am on the remaining areas of concern and my suggestions of steps you can take to address them.
          www.cardas.com/room_setup_main.php

    I just wanted you to realize this from the beginning and attached their link for your reference. I'd suggest you just follow their suggestions, determine for yourself how it performs in your system and room both sound performance wise and aesthetically and then experiment after with speaker placement adjustments that may perform better in your determination.
    According to Cardas, the optimum positioning of your 4319s would be with them positioned 7.5' apart from each other, 7.5' out or away from your front 16' wall, each speaker 4.4' away from the nearest side wall and with your listening seat exactly between the speakers and 7.5' away. They state that this is the recommended starting positioning and that making a series of small speaker position and toe-in angle adjustments are required to fine tune the stereo imaging, with the presence of a realistic, solid and stable soundstage illusion of vocals and the vocalist between the speakers being a good measure of positioning success.    

2. Procedure for optimizing the phase control settings on all four subs for improved subs and speaker integration:

A. Invert the polarity on both speakers by reversing the positive and negative speaker wire connections on the 4319's terminals only (NOTE: do not reverse the speaker wire connections on the amplifier, just reverse the speaker wire connections on the speakers). IOW, instead of the proper connections on the 4319 speaker terminals and speaker wires being pos. to pos. and neg. to neg., reverse them to pos. to neg. and neg. to pos.
B. Play some music with good and repetitive bass and sit in your listening chair.
C. With only Sub#1 powered on/active and both 4319s playing, have an assistant very slowly rotate the Continuously Variable Phase Control on Sub#1 until the bass sounds the weakest and worst to you.

D. Leave Sub#1's Phase control at this setting since the sub and 4319s will be both precisely in-phase once the 4319's polarities are not inverted and returned to normal.

E. Repeat steps A-D for Sub#2-4

F. When all 4 subs have had their Phase control set in this manner, return the speaker wire connections on both of the 4319's speaker terminals to the normal, pos. to pos. and neg. to neg., positions.

    This polarity inversion method works well because it's easier to
determine when the bass sounds the weakest and worst than the strongest and best.  
    The remaining two sub controls useful for optimizing the blending, or seamless integration, of the very good bass produced by your new 4-sub DBA system and the very good midrange and treble produced by your pair of JBL 4319s are the Volume and Crossover Frequency control settings on all four subs. Unfortunately, I'm unaware of a simple and effective procedure, like the one described above for optimally setting the Phase control, for optimally setting the Volume and Crossover Frequency
controls.  
    Based on my experience using a 4-sub DBA system, I consider the specific actual positions of the Volume and Crossover Frequency controls as the most important determinants of how well the bass produced by a 4-sub DBA system will blend, or seamlessly integrate, with the main speakers, as separate controls that are actually very interdependent in terms of their ability to influence the overall sound and performance quality of the combined system and as controls that are likely to be readjusted periodically over time as experience is gained and personal overall system preferences develop. Hopefully, you understand why I'm unable to offer simple procedures on how to set these controls and you quickly become proficient at setting them yourself on your new 4-sub DBA system.
     
    However, I can offer some advice and guidance.  The Volume control setting was probably the simplest for me to set since I don't want the bass to be overemphasized in my system. If you feel the same, then it's just a matter of matching and setting the Volume level on each of your four subs to the relative volume of the midrange and treble frequencies played back by your main speakers. The Swarm system requires only the setting of a single volume level on the amp/control unit, which I have set at 11:00 which is about 45%, but your custom DBA requires the desired relative volume to be set on each sub individually.
    The Crossover Frequency requires a bit more planning and experimentation. First you need to determine the bass extension limit of your main speakers, a good indication is the published rated frequency response figure usually stated as a specific frequency range capacity listed in hertz which indicates the upper and lower frequency limits along with a decibel deviation in output over the entire specified frequency range. For example, my Magnepans are rated at  34Hz-26kHz +/- 3dB, 34 Hz -3dB being the important figure for the bass extension limit.  Your JBL 4319s are rated at 38Hz-40kHz -6dB, 38Hz -6dB being the important figure for the bass extension limit. Since 3dB is the smallest change in loudness humans typically can notice, -6dB at 38Hz indicates that the bass will output at that frequency will be noticeably lower.
       Second, you need to decide whether you'll run your main speakers full-range or limit their bass output to a certain limit, I believe the built in filters on your SB and PB subs only allow limiting your main speakers bass output to a fixed 80 Hz and below.
     I did not perceive any sound quality benefit on my system by restricting the bass frequencies my amps and main speakers were responsible for reproducing so I run my mains full-range and usually have my Crossover Frequency set at 40 Hz, which means my Swarm DBA is reproducing the bass from 20-40 Hz.  
     However, I suggest you try both options and decide for yourself whether running your 4319s full-range or with restricting their output to 80 Hz sounds best to you.  If you prefer them running full-range, I'd recommend initially setting the Crossover Frequency on each of your subs to  45 Hz and then experiment by progressively decreasing the Crossover Frequency on each sub as low as possible while still liking the overall system sound quality.  If you prefer them running with the bass restricted to 80 Hz, I'd recommend initially setting the Crossover Frequency on each of your subs to 85 Hz and then experiment by progressively decreasing the Crossover Frequency on each sub as low as possible while still liking the overall system sound quality.  
     For best overall results, I'd also recommend initially setting the Volume level on each of your subs to your best estimate level and then experiment by progressively decreasing the volume on each sub as low as possible while still liking the overall system sound quality. 
     Remember, the goal is not to constantly be aware of your upgraded bass performance, the goal is for your overall system to effortlessly reproduce whatever bass the music, or any HT content, calls for whether it's accurate, detailed, quick,taut and rhythmic bass or accurate, detailed, sudden, deep, dynamic and powerful bass.


Enjoy,
Tim

I’ll report back in a few weeks after everything is set up, and I’m able to spend some quality time with the setup. The initial dip into this has been promising.

As for the SB, I think they will still be place closer to the main speakers, as they integrate better, because they produce a puncher upper bass output. The PB will be set further back. 

The phase control method is a great idea. 

For me the crossover points has been easy, as I can hear when the crossover points are too high. The imaging starts to feel like your in a hallway and it the upper bass/mids get harsh. 

Volume will be the fun factor, I think everyone has different tolerance for bass notes, and it is going to be as high or as low as one can tolerate. 

Off to a great start. 


Thanks again.

Hello Watcher,

     Okay, I'll keep monitoring the thread. I you have any questions, you can always pm me, too.


Good luck and take your time,
 Tim

After a week of setting up, my review of the system is consistent with the one I've posted. 

I ended up moving the speakers forward 3 feet away from the wall (I have other things in my room so I can't move them that far away). The imaging improve marginally, a bit cleaner. 

Did the crawl test, and the subs are about the same relative place, with two against the front wall and two behind the seating position. 

The phasing was next, using the reverse polarity method, and since the subs are all about equal distance from the seating position and in the relative to the speaker. So all phasing ended at pretty much zero.

Crossover same concept, I paid attention to low mid range harshness, and tuned it to a point where harshness is gone. Starting with the pairs closest to the speaker, the ones far away should not be set higher than front. If you still sense harshness, the ones closer to you should be crossed over lower than the fronts. 

Volume is fun to play with, if you set them all the same you get a better sense of space, but if you set the front higher than the rear, you get stage imaging. I'll play with this setting and see what comes from it.  
 
The sound is effortless and cohesive extending the dynamic range of my speakers and enhancing the sense of space. For about 2 grands its a deal compared to not even the price of one high end sub.