My experience adding subwoofers to 2 channel


My Kappa 9 speakers are rated to 29hz and they sound pretty good in my 18x24 room...powered by McIntosh mc1.25 amps...l was looking for another layer of bass to enhance the sound..my first experiment l took my SVS pb16 ultras from my theater room and tried them first...it sounded terrible,didn't blend well..couldn't hear a difference until you turned in up then it rattled the room apart........my final experiment worked..l used 4 Velodyne minivee subwoofers(1000 watt rms class D sealed 8 in.) and after hours of calibration l hit it......lve got the bass response that exeeded my expectations. ....l should have done this along time ago....can anybody tell me of another subwoofer that may work even better?
128x128vinnydabully
I have bern right around Audio as a Audiophile over 35 years and Audiostore
owner until 08 . Have owned every major brand subwoofer in the past 3 years .
without question the best subwoofer with the most technologies by a customer untrue mile trickle down technologies from their flagship SVS ultra-16
is the Hot New SB 3000,13 inch sub Loaded with anything  no it does not has Bass EQ, but potentially much better , great app, powerful amp he only split voice technology in the world and makes a big difference at low volumes,not boom ,the center is smalller , for at low volume levels, as you crank it up,
it then uses the outer portion  50 MHz,52 bit Analog devises processor 
Nobody else has this high tech built into a under $2k sub ,at $995
i could not find better at 2x that it is that good. And I will probably buy a second sub ,for 2 good subs are always better then one to balance the room out .
even with one sub this Sb 3000sub is far moretunefull then any rel, $1500 JL audio I sold, rythmik,Velodyne, Syzgy,just go to utube, and see all the great reviews 
it is has been  out only 6months and is  the best under $2k sub on the market .
real tuneful articulate bass. It even has a 3 band parametric eq .
if you buy a usb Mike, Free REW Room wizardfree  Room software you can totally Taylor your room exactly to your preference with a little time and experience . Just check it out , who else will give you free shipping , a 45days
audition and they will pay for the return, and a full 5 years parts and labor.
that is truly having confidence in their product . The $3500 JL fathom ,ar$3500
was the only sub to be neck and neck with the $1995 SVS Ultra 16, the 
New baby brother SB-3000 has -0 competition ,even their 4000 model does not have the latest technologies , just bigger amp slightly bigger driver.
this 15 x17 sub with 13 inch driver is without peers . My brother has 2 SVS ultra 16 and he even agreed this sounds like a smaller  brother.
just check it out  Fantastic !!

bdp24:

"The plate amps in the Rythmik subs provide all the controls mentioned by @Noble100: volume, phase (180 degrees via a continuously-variable rotary knob), x/o frequency (40-120Hz) and slope (2nd/4th order), plus damping, a rumble filter, one band of PEQ, and both line level (RCA jacks) and speaker level (binding posts) hook-up. There is no reason four of them cannot be implemented as a swarm. You will however need four AC outlets. ;-)"

Hello bdp24,
     When did I state that you can't use four Rythmik subs in a swarm type (4-sub distributed bass array) system?   
     The answer is I didn't.  You can use any 4 self amplified subs you'd like to create a custom DBA system.  
     What I stated is that, if you choose to use 4 self amplified subs (like the Rythmik) to create a custom DBA rather than an Audio Kinesis Swarm or Debra complete kit DBA (which consists of 4 passive subs and a separate amp/control unit to power and configure all 4 subs as a group), then the setting of the volume, xover frequency and phase controls will need to be done individually for each sub rather than all at once as a 4 sub group on the AK sub amp/control unit.  
     My intent being only to inform readers of this fact so they can make an informed decision on whether to choose between a custom DBA system using 4 self amplified subs and a complete custom or AK DBA system using 4 passive (unamplified) subs.  
     In fact, I believe using 4 self amplified subs, like the Rythmic with individual volume/xover/phase controls, does offer more configuration flexibility than setting all these controls for all 4 passive subs as a group on a sub amplifier/control unit.  It's just that it complicates DBA configuration, requires more time and is an individual choice best made with full knowledge.
     The key to the DBA concept working so amazingly well is the use of at least 4 properly positioned subs, the fact that it works extremely well with  a wide variety of sub types, sizes and quality just demonstrates the validity and flexibility of the DBA concept.

Tim
larry5729

Were u talking to Vinny or Me Larry?

I posted the theater link where we have the Wilson Alexx speakers.  But no price. They are $109 K/pair. Except the link lead to the page that priced out the system.  
My boss and former roomate from school owns the showroom, and yes, the Wilson Alexx speakers are certainly worth every penny for the sound.

If someone has the money, and can also have a dedicated, full blown treated room as good as the custom listening room that Robert Harley shared in an article in an issue or two ago, then yes you can totally hear it.  It is really enjoyable to just have folks come in for a demo in all 3 listening rooms, saving the "Transporter" room for last.

I enjoy MartinLogan ESL's (2500/pr) , I enjoy PSB Imagine B speakes (1300/pair), I have MartinLogan Motion 2's in my office with a REL T5i, which sounds great.  You just shift gears when you listen to a pair of Wilson Alexx with D'Agostino Progression mono blocs.

I love listening to Vinyl in there, and then comparing it it to streaming from Tidal, using Roon, thru the Vivaldi DAC and dCS Network Bridge. Usually the Vinyl has greater detail (Brinkmann Bardo turntable w Audio Research Phono 3 preamp), but many times a solid MQA Master recording gives the Vinyl a run for it's money, almost :) 


http://audibleimagesav.com/the-transporter/


audioman58

I would really like to hear  SVS ultra-16 and the New SB 3000 you mentioned.

Blending a single sub or a pair with 2 channel system does make all the difference in the world.

Pretty cool you had a store till 2008 !

     I thought it would be useful to cut and paste a response from Duke Lejeune, owner of Audio Kinesis and advocate of the DBA system concept, from a thread I started awhile ago on the DBA concept. Here's a link to the full thread followed by Duke's relevant response:

https://forum.audiogon.com/discussions/anyone-else-using-an-audio-kinesis-swarm-or-debra-distributed...


Duke:

"Just for the record, I got the distributed multisub idea from Earl Geddes. It happened like this:

I was driving Earl to the airport after CES in January of 2006 and we were stopped at a stoplight. He said to me "Duke, I’ve figured out how to get good bass in a small room. Use four small subs and distribute them asymmetrically. Each will produce a different room-interaction peak-and-dip pattern, and the sum of the four dissimilar peak-and-dip patterns will be much smoother than any one alone." A lightbulb went off in my head as I immediately realized this was "the answer", so I said, "Can I license that idea from you?" He replied, "You can just use it." And then the light changed. It was that fast.

Now let me explain what I meant by "the answer": For years I had been trying, off and on, to build a subwoofer that was "fast enough" to keep up with Quads and Maggies. I was a SoundLab dealer, and the SoundLabs are big enough to have good low-end extension, but they are too big and expensive for most people. I figured the first guy to make a sufficiently "fast" sub would have a potential market among Quad and Maggie owners. Being a longtime amateur speaker builder, I tried pretty much everything except for a horn: Sealed boxes, aperiodics, low-tuned vented boxes, transmission lines of many different geometries, equalized dipoles, and isobarics. None of them could "keep up" with Maggies and Quads. I was stumped.

But the problem was not the "speed" of the subwoofer - it was the peak-and-dip pattern that the room inevitably superimposed on the sub, which totally dominated the result. Yes some subs were audible improvements over others, but none could blend with Maggies or Quads without there being a distracting disconnect between the subjective lack of "speed" in the low bass and the rest of the spectrum.

You see, woofer(s) + room = a minimum phase system at low frequencies. What this means is, the frequency response and the time-domain response track one another. In English: Where you have an in-room response PEAK is where the decay is SLOW, and it doesn’t matter how "fast" the woofer is. The good news is that, when you fix the frequency response you ALSO fix the time-domain response, and vice-versa! So, SMOOTH bass is FAST bass. This is why the lightbulb went off in my head when Earl described his idea to me.

A distributed multisub system like the Debra or Swarm or your own set of four subs results in four (inevitably nasty) peak-and-dip patterns, but their sum will be much smoother than any one of them. Actually you will end up with MORE peaks and dips, which will be much smaller and much closer together. This "closer together" part is quite beneficial - the ear tends to average out peaks and dips that are within 1/3 octave of one another. So the subjective improvement is often greater than one would expect from merely eyeballing before-and-after curves.

One of the things to be aware of if you’re going to "roll your own" distributed multisub system is this: At the upper end of the bass region the outputs of the subs will be combining in semi-random phase, but at the bottom end of the bass spectrum their outputs may well be combining in-phase or nearly so, if the longest room dimension is a small enough fraction of a wavelength. This results in a rising response as we go down in frequency (and remember that the time-domain response tracks the frequency response). So if you already have two subs that go real deep, you might do better by adding two more that do not go as deep. Or vice-versa.

In the Debra and Swarm systems, the subs’ native response curve falls by about 3 dB per octave from 80 Hz down to 20 Hz. This approximately compensates for typical room gain. Then in most rooms we reverse the polarity of one of the subs (usually the one farthest from the main speakers), and this extends that semi-random-phase addition down into the bottom of the bass region, further smoothing the response and offsetting the rising bottom end that we would otherwise have. Also the down-firing ports on the Debra and Swarm modules are pluggable, converting the enclosure into a low-tuned sealed box, to give further adjustability (given that every room is different). And finally, the amp that we use has a single band of parametric EQ, in case there is still a peak at some frequency.

Speaking of EQ, why not use a single sub with EQ to fix the frequency response curve, simultaneously fixing the time domain response? EQ works great at a single listening position, and can work well within a small listening area. But the larger the listening area that we try to improve with EQ, the smaller the improvements are going to be. This is because the afore-mentioned room-induced peak-and-dip pattern changes dramatically as we change locations within the room ,so EQing a single subs works best for a single location. Unfortunately when we fix the frequency response in one location, we are making it MUCH WORSE in other locations! This is because the peaks and dips are at different frequencies at other locations. But with a distributed multi-sub system, the spatial variation (difference in frequency response from one location to another) is also greatly reduced. So if by chance there is still a peak with a distributed multi-sub system, chances are it’s a GLOBAL (room-wide) rather than a LOCAL peak, and therefore is a very good candidate for correction via equalization.

Big rooms have smoother bass than small rooms because they have a more dense modal behavior: The room-induced peaks and dips are more numerous and more closely spaced. A distributed multisub system can make a small room mimic a larger room in the bass region by doing the same thing. And this will sound counter-intuitive, but the smaller the room, the more it will benefit from a distributed multi-sub system.

One other bit of trivia: The other main researcher behind distributed multisub systems is Todd Welti of Harmon International. He investigated symmetrical rather than asymmetrical arrangements. Anyway Earl and Todd were developing their ideas AT EXACTLY THE SAME TIME, but each was completely unaware of the other’s work. So I guess it was an idea whose time had come!

Robert E. Greene of The Absolute Sound gave the Swarm a Golden Ear award again this year (It got a Product of the Year award back in 2015). So despite the passage of time, apparently the distributed multisub idea hasn’t become outdated.

Duke

dealer/manufacturer/caught in limbo?"


      I think this explains why the time-domain is much less important on deep bass response than some seem to believe it to be.  It also explains the importance of how our brains process the presence of multiple bass peaks and dips at multiple frequencies in a room, referred to as psycho-acoustics, which is a bit counterintuitive but is a crucial factor in how a DBA so successfully utilizes the differentiation between the physics of how deep bass very long soundwaves behave in a given room and how we perceive those soundwaves.  

     I admit I don't understand this subject in detail but I can state with certainty that the concept produces what I consider state of the art bass response in my system and room without the use of any room correction software or hardware, DSP, equalization and bass room treatments.  

     I know I'll always have this excellent deep bass foundation that seamlessly integrates with not only my current main speakers on music and ht, but it will do so equally well with any main speakers I may use in the future.  I've found my huckleberry.

Tim