Vandersteen Sub woofers v Rythmik Subs

@bondmanp  I believe Tomic 601 is referring to the M7 HPA power amps new to Vandersteen's line.

you do need to be careful to not fry your sub amp......grounds and hots hyper critical.....

What do you mean by this?
Also, just got my TS plugs last night, so itching to see if a simpler run from the pre-amp to the amp (although now unbalanced) improves sound quality.
I do have an open floor plan in my main listening area which is open to the kitchen/dining room, so I have to deal with blenders, running water, and screaming kids, so not conducive to critical listening (It's actually rare when I get the house to myself...grrrrr...) Hopefully I will be able to do some good tests in the next couple days, however.

M7 high pass filter in cast box, with carbon fiber cover, guts are different, especially the battery config for DBS
they are around $2k at retail
i got them when I had 5a and went from a SE power amp to a balanced Ayre, so I cannot comment on sonic change with only the filter as a variable.
i do however trust that RV would not put out a dolled up sonic equivalent...
the change to Ayre and M7 was staggering...
i sold the M7 filters here on agon a few months ago, astute buyer...$1300, they have WEL pigtails....

bstat
the blender can be thought of as a diffuser of sorts i guess
hope you get some quiet time

download the sub manuals and you can read all the cautions on grounds and hots...

As I'm not a DSP user for home audio (or pro audio for that matter, although I utilize graphic and parametric EQ in pro mixing work) as it seems to rob a little of the soul from music (my imagination possibly, and this opinion is based on listening at length to a friend's rig). Note there's a REL Q150e on Ebay for cheap...I have one and it's amazing. I get the swarm idea as it makes perfect sense, but the REL "high level" thing also makes sense, and works for me. I now have my smaller (downfiring 8" speaker) REL in a permanent corner behind the left main, and my Q150e now can be moved away from the corner if I want it closer to the right main speaker, and that offers some other tonal response options I like to hear. Moving a speaker around is about as analog as you can get, and I like it.

Hello wolf_garcia,

     " Moving a speaker around is about as analog as you can get, and I like it."

     Since you seem to enjoy experimenting, I thought you might want to try positioning your REL-Q150e at your listening position then walk around your room listening for the spot you think the bass sounds best.  
    It's a very good possibility that locating your Q-150e at the spot you thought the bass sounded best will provide the same bass quality at your listening position.  
     If the spot makes sense functionally and aesthetically, you may be pleasantly surprised at the sound quality.

Just something to try,
   Tim

so got rid of the Samson S-convert and now running strictly unbalanced with my TS connectors, I must say the biggest difference has been the decrease in background noise. On LPs the back ground hiss is barely noticeable and have to get right up to the speaker to hear it - and this is at a decent volume to boot. I did not get a proper sense of differences in sound stage since I have been unable to position speakers for prime listening at this point. But I have been very pleased with the results so far and only wish I would have done this years ago.

Because of this it will help me implement the 2wq subs in a cheaper manner (starting with the WX-2 variable cross-over to figure out the best setting for my amp, then purchasing the fixed cross-overs based off those results) - Although I do wish I could get the HP-5's, it's not realistic for me at this point financially.

Now if I can just find a good deal on a 2wq or two starting on July 1st...
(Financially this would be the optimal time)

The HP-5's are really the way to go. If you buy them new, make sure you give them ample break-in time. When I first got mine, new out of the box, they sounded only marginally better than the X-2's. But after 4 to 6 weeks, WOW, did the sound ever open up! It caught me by surprise when I started to notice it. At first I wasn't sure what I had done to improve the system so greatly. But then I remembered. I tried the X-2's again and the sound just closed in. The bloom was gone, air around the instruments and vocals almost totally dis-appeared. I was in a financially constrained condition also, but eventually was able to spring for the new HP-5's. If you ever find a used pair with good batteries, go for it! And good luck!

As far as what impedance to match the cross-overs at - I noticed that my amp has an impedance of 10k ohm for balanced connections. Does this mean that I should match up the WX-2 to 10K? I have heard that people often find that they get better results if they go one step lower. so in this case I would go to 7500K? Does the WX-2 go this low?

The WX-2 seems to be designed for single ended (RCA) only. In that configuration, you can select the 10k input impedance to start with and listen. It does have one lower position below 10k and that is 5k which is pretty much the limits for the WX-2. Make sure of your amps input impedance, because if you go accidentally to low, you can over tax the amp modules in the 2Wq sub. I had this conversation with Richard Vandersteen and got  quite the scolding for suggesting going to low on the impedance selection. He said his warranty would not cover this type of damage to the amp modules, so use caution and a low volume level to start with.

I, too, have an issue with my McCormack DNA-1 monoblocks, in that they have pretty low impedance-like yours.
Using balanced, I can only get to 22Kohms. And, I think going lower would be beneficial. So, either I go to unbalanced or have SMc Audio redo their work. I am leaving it for a time when I can reconfigure my wiring.
Until then, I still have the Atma MA-1's and Ayre MXR's, so I am in no hurry. (It's nice to have options).
Bob

MXR as spares..... :-)

first time I heard Model 7 was at RV’s house.... running on MXR...

( his amp was in development )

give that some thought.....

bstatmeister: "Honestly I would rather buy an extra sub than a cross over - at least to start off with...lol"

    I have no experience with the Vandersteen crossovers discussed but I'm fairly certain that having 2 subs rather than just a single sub in your system, provided both subs are properly positioned, would result in a more significant and obvious overall system performance improvement than utilizing a high quality crossover would.  You could always add the crossover subsequently if you thought there was a need.  

Tim

Yeah, before the x-overs, would probably upgrade to the latest model 2 after I buy the 2 subs (my model 2Cs are pretty old at this point and will need to be put out to pasture in the next 5 years or so. I think at some point I will want the HP-5s, just trying to improve the most noticable things first.

" @noble100 and others interested in room acoustics: which other fora are you active in?

I'm interested in discussing and posting some measurements (which Agon doesn't allow) and would live to engage others who share that interest.

Cheers!"

Hello lewinskih01,

     Sorry for the delayed response, I just noticed your question today.
   
     First, by your 'Cheers!' sign-off, I inferred that you're an English brother. 
     Unfortunately, it appears we Americans often prefer the siimplest form of things both grammatically and presidentially. We typically employ 'forums' as the plural of 'forum' and only employ the original Latin 'fora' as the plural form when  we're referring to  the marketplaces or public places of an ancient  Roman city forming the center of judicial and public business.
     I realize there are other variances between English and American grammar.  For example, the majority of Americans describe our current president as an 'idiot' or 'dope' depending on region, while the majority of Englishmen likely describe him as a 'wanker'.
 To answer your question, however, I mainly participate on this forum for audio discussions but would recommend other forums, such as Audio Circle and DIY Audio, for subjects such as room acoustics discussed in more detail and scientifically. I participated and learned a lot about class D amps and in-room bass response on those fora. Doing a Google search on "room acoustics" would also prove useful.

Cheers!
 Tim

" @noble100 and others interested in room acoustics: which other fora are you active in?

I'm interested in discussing and posting some measurements (which Agon doesn't allow) and would live to engage others who share that interest."

Hi lewinskih01,

     Sorry about the late reply.  I responded earlier to your question but just realized my post was removed, probably by the moderator due to negative references to our president I threw into my response.
     The other forums I would recommend to you are Audio Circle and  DIY Audio.  I learned a lot on these sites at separate times in the past when I wanted to learn more about class D amps and in-room bass response.  I consider both of these sites to be more concerned with empirical data and a scientific approach than the generally more opinion based discussions on this site. 
      Doing a Google search on "home audio room acoustics" would likely also be useful. 

Cheers!
  Tim

As an audio fan and sound engineer/musician (over 5 decades and counting) there's a lot of practical info in my feeble brain, and I never take for granted where I place my mains or subs, so there's that. I've heard the "put the sub at the listening spot" thing before, and I've never had cables long enough to try that. I adjust these things a little anyway (mostly for level which is source dependent). Works for me. My new thing of being able to move the Q150e front firing sub is a revelation...I just slide it around within it's cable limits to tune it to whatever I am listening to, the other downfiring sub stays put.

@noble100 

Hey Tim!
This Horacio, the Brit from Argentina!!! Hahaha. Fortunately I got to see your post early on, but had not had the time to reply. I'll keep away from political remarks to circumvent censorship.

OK, I'll say forums :-)
I'm very often at DIYaudio, a lot more than here these days. Indeed, there are several forums where room acoustics are discussed. I worked on room acoustics before and I'm getting ready to take it to the next level. Another level of magnitude vs other topics often discussed. It's unusual to come across people who also study it - hence my question.

Cheers mate!
Horacio

Sorry I'm late to the party, lol.  Haven't been on as much as I recover from surgery etc.. still.  I'm a Quatro owner and went that route because I needed the bass EQ.  I'm sure Tomic and others have gone over the V advantage of the Sub amps taking on the sonic signature of any main amp it works with.  The cross over also allows the main amps to only have to process 100hz and up, so that really frees them up to sound even better than they normally would.  Once I installed the Quatro's I noticed my Ayre AX5/20 sounded noticeably better as it was more relaxed and much more dynamic.  That was a huge issue for me and it was an extra benefit for me.  This is a huge reason I love his subs, even the ones without the EQ like the new ones do.

I know this gets discussed a lot, but it needs to be.  I also like the 3 8" woofers for their speed.  I have heard the 2wq's a lot and feel they go plenty deep in a room that can handle it.  Most rooms can't handle ultra powerful sub bass.  Standing waves and other excited room nodes (around 50hz) really screw up the sound.  Like Wolf and others, I dislike all the high end DSD I've listened to.  

I do recommend 2 subs no matter what you go with.  The eq V subs are going to most easily fit into any room.  That's why I upgraded to the Quatro from my beloved Treo's.  Never looked back.

Thanks for sharing.  I do love my Quatro upgraded from the Treo. Just smoothing out the bass has helped teh sound tremendously.  I have heard a substantial upgrade in the sound of my amp now that it doesn't have to do any heavy lifting below 100hz.  

I auditioned most things under the sun and didn't like the speakers that used DSP as I always heard it unlike the analog approach Vandersteen is still using.  

Hola Horacio,

     So, your 'cheers' sign-off does indicate your British heritage but you're now living in Argentina, interesting.
     Yes, I share your interest in room acoustics, have read many white papers from leading acoustic scientists' research and read a lot of various online audio blogs on the subject.  I've learned quite a bit but definitely do not consider myself an expert.
     My main focus has been an attempt to attain the best sound reproduction for 2-ch music and ht in my 23 x 16 foot living room.  I've basically been trying to adapt what I've learned to my room and system. 
     For example, one of the principles I learned was that it's more difficult to attain good bass response in a given room than good mid-range and treble response
.  Therefore, I decided to initially concentrate on attaining very good bass response in my room as my goal.
     The findings of acoustic engineers Earl Geddes and Floyd O'Toole were instrumental in my decision to employ a distributed bass array system to attain state of the art bass performance.  It has been scientifically proven, by Geddes and O'toole and independently verified by others, that bass standing waves are reduced (and bass response improved) in any given room as more subs are added.   
     They also found that bass standing waves will be significantly reduced as subs 2-4 are added and that the vast majority of standing waves are eliminated by deploying 4 subs; any subs added beyond 4 will only result in relatively smaller improvements.
     Because of the above,I decided to purchase and install the Audio Kinesis Debra distributed bass array system that consists of four 1' x1' x28"  44lb. 4 ohm subs with 10" drivers all powered by a 1K watt class AB amp.  
     This system has allowed me to reach my goal of very good bass response in my room as a solid foundation for my system to be built upon.  It not only provided accurate, smooth, textured and effortless bass at my listening position but also at the 5 other seating positions in my room. I believe it's possible to achieve this level of bass response utilizing as few as 2 subs if properly positioned but the bass will only be optimized at a single 'sweet spot' seating position, not throughout the entire room. 
     Once the bass system was installed and functioning at a high level, I found I only needed to independently dial in the mid-range, treble and sound stage imaging and illusion at my listening position.  I have large Magnepan 2.7qr panel speakers and this was relatively easy to do by experimentation with their positioning; distance between the left and right speakers, distance from my listening seat, distance out from the front wall,angling or toe-in and room treatments at the first reflection points.  
     I've come to the conclusion that it's best to treat any sound system as 2 systems: a bass system and a mid-range/treble sound stage imaging system.  I've arrived at this conclusion by research but also by applying this research in my own room and system(s).

Hope this helped a bit,
 Cheers,
Tim 

Well written Tim . You are preaching to the choir or at least me    

Funny as I've been ready to get the Audioquest power cables, but am thinking I really need to get my acoustics down first.  That will make a larger upgrade in sound than even great power cords regardless of how great they are (they too are a component upgrade).  

Speaking of Vandersteen Sub woofers, looks like they got the page up for the SUB NINE. Holy smokes that looks like a beast! Check out that last pic next to the model 7s

http://vandersteen.com/products/sub-nine

It's really interesting with the first sub I ever owned being the Vandersteen 2Wq. I am using it with a pair of Treo Ct's. Bought the HP-5 crossovers, new. I put the lone sub in the right corner, adjusted the crossover frequency, and output of the sub. That was all there was to it! Sounded great from the get go. I used a recording of a jazz standup bass and adjusted output so upper bass frequencies were same volume as lower bass frequencies, as RV suggested. Tried bringing out the sub from the corner, but corner placement in my room sounded best. Near perfect balance of frequencies across the board. Even when a stand up bass is located left in the soundstage, the speakers make the sound come from that position perfectly even though the sub is in the right corner. The front main speakers maintain a stable image from left to right. What more could I ask for???

hz is in the music they will reproduce it well. my understanding is the 9 is for larger rooms, more spl and tge driver is optimized for a very narrow range like 60 hz and down, hence the choice of driver.....

every now and then, often near the end of a listening session with the 7’s and most likely a nice bottle of Red, i imagine them in the corners.......how could my wife notice them ???????????

hz is in the music they will reproduce it well. my understanding is the 9 is for larger rooms, more spl and tge driver is optimized for a very narrow
range like 60 hz and down, hence the choice of driver.....

So the built in subs in the model 7 still handle the upper bass and only the super low frequencies are handled by the 9s? Make sense since the super low frequencies wouldn’t need drivers that have to be as fast and can focus more on pressurizing the room

Thanks for the link bstat. I was a little disappointed in the design of the subs. They seem a bit stark, but I guess after looking at the 2wq's for so long, any change would be unsettling. The good news is that they are a bit more compact (17x20x21 vs. 24x24x24), so should be much easier to place.
B

bstat....my first sentence got cut...

it was :

9 was developed to use with primarily 7, perhaps quattro for very large room, higher spl needs....the 7 in particular with the aluminum cone push pull built in sub is capable of amazing bass...the 9 is literally a below 20-60 hz machine where a large driver is needed or best suited for the duty cycle, etc.....

i will say ( again ) you might want to look for a pair of 5a......

Jim
Sole Survivor Proprietor- Dusk to Dawn Audio, Ltd 

" Even when a stand up bass is located left in the soundstage, the speakers make the sound come from that position perfectly even though the sub is in the right corner."


Hello mr_m,

     I find this to be is a very interesting phenomena of human hearing that I think is important to realize when we're setting up our systems for optimum bass response in our rooms..
     When I first installed my  Audio Kinesis Debra system, I was concerned how bass emanating from 4 subs arrayed throughout my room would affect my system's sound stage illusion normally spreading from wall to wall and sometimes wider while varying in how many seemingly feet in depth depending on the quality of the recording. 
     These 4 subs are run in mono and I was wondering if I'd still be able to perceive bass instruments as being located properly and precisely within this sound stage illusion.  This very life-like illusion on good recordings is something I really enjoy and didn't want to lose.
     Fortunately, the sound stage illusion was even more palpable and life-like with the Debra in place.  The locations and spacing of Instruments and vocalists within the sound stage illusion were only enhanced.  Even though the bass is in mono and the bass sound waves are coming from 2 subs along the front 16' wall and one along each of the 23' long side walls (about 4' in from the back 16' back wall with my listening seat centered on this back wall),  I always perceive the bass as coming from the proper position within the sound stage illusion at the front of my room on both music and ht.  I  perceive no bass emanating from the 2 subs closest to my seat, just from instruments and voices within the sound stage illusion.   
      I'm very pleased with this bass response and illusion but it is odd how we humans perceive sound; a combination of our ears receiving the sound waves and our brains processing them. 
     I think this affect should be considered as a factor in room acoustics when assembling a home audio system.  I believe this phenomena can be explained by the fact that bass sounds are rarely just bass frequencies and typically have harmonics exist that are at above bass frequencies.  Humans are poor at identifying the location of low frequencies but much better at doing so as the frequencies rise into the mid-range and treble range. 
     I think the scientific explanation is that the higher frequency harmonics of bass sounds allow our brains to better place the source of bass sounds/instruments in the sound stage illusion.  I realize this may be an oversimplification and the actual ear and brain relationship is likely much more complex, but I think it adequately describes the process.

Tim  

Even without talking about the brand you want to use, a subwoofer is still a difficult tool to set up. You need different parameters to adjust. 

All the subwoofers with an inbuild roomacoustic system are not flawless. In  the past we did not even had any roomacoustic adjustments. Based on my expeirence and feeling for acoustics I was able to creat a level in integration none of my collegues ( audio shop) could create.

But, even this not flawless. At the end you want and need the highest level in integration. With our own developed Statement Audio Pro-measurement we can create a level wat is both superior tot the old 'analogue' way amd the subwoofers with an inbuild acoustic system.

There is only one way to get it right and that is a roomcorrection system what measures the loudspeakers and subwoofer at the same time. Rhe level we reached was what I had in my head and mind 10 years ago.

I thought this would never be possible to create. But now in 2018 we reached a stunning level in integration and even with the new Audioquest Storm cables we can reveal details of a recording which are gone without the use of the subwoofer, S.A.P.-measurment and the Audioquest new powercables.

The other thing we created is what I call a 3D matrix. This is feeling the low energy of the loudspeaker at different places in the room depending where it is on the recording.

At the end of 2017 we were able to bring the energie even in height and depth. But the latest S.A.P-measurement and Audioquest new Storm cables created a new level in integration and precision.

The first time I demoed it to my collegue he started to shake with his head. Like this is not possible what I hear. But I switched the subwoofer on and off so it became clear how huge the difference is between the subwoofer on and off.

This demo was in stereo. We seldom sell stereo these days without the use of a subwoofer. Due to the fact that we can create a level in realism and emotion what without a suboofer is not possible. Even when you would use the biggest loudspeakers in the world.

To the good people on this thread, I have been very happy with the 11 band eq Richard uses in my Quatro's as it really fixed the problems I was having.  Very very happy with the sound that I'm getting in a very difficult room.  I look forward to fixing up some of the room acoustics in the next few months hopefully.  

Those 9's are sick for sure. Tomic, I can't wait for your's to get installed.  LOL.....I'm going to audition his new amps when they are ready and figure out if it's worth upgrading, lol....So many cool toys to play with now.

There are a few ways to get what you want for bass.  Nothing is difficult in set up, but it will take time to get it right no matter what you have.  Integrating a sub can be difficult.  I personally do like EQ (analog) as it smoothed out the bass performance in my room GREATLY.  It made a huge difference.  I also like the Vandy subs because they take on the sound signature of any amp that they are crossed over with.  I don't know of any other subs that do that and it make a nice difference to my ears.  

I read so many talking about an array of 4 subs.  that sure can help, but  2 subs are already a big advantage over one and 4 gives flatter response IF the sub has no other way to EQ the problems remaining.  2 quality subs with room EQ will trump most 4 sub systems.  We are also talking a more wife friendly room (I too like a cleaner looking room now days).  Another problem never mentioned is when the subs have drivers pointing into the listening space or ports the sidebands as these have a negative impact on imaging and sound stage.  Again, this is something that is never discussed, but very real.  

REL subs also "take on the sound signature of any amp that they are crossed over with" by utilizing the amp's output with their recommended "High Level" input. REL should market some sort of universal "longbow" wireless gizmo that would work with older RELs like mine that would allow more than 2 RELs in a system maybe...I say 2 because when I put the REL cables on the binding posts I don't want to squeeze more than 2 sets of REL specific wiring on the posts (using spades together with bananas for the main speakers...a crowd but manageable), or combine wires together to get that signal. Wishful thinking, or it's out there and I don't know it.

" I read so many talking about an array of 4 subs.  that sure can help, but  2 subs are already a big advantage over one and 4 gives flatter response IF the sub has no other way to EQ the problems remaining.  2 quality subs with room EQ will trump most 4 sub systems.  We are also talking a more wife friendly room (I too like a cleaner looking room now days).  Another problem never mentioned is when the subs have drivers pointing into the listening space or ports the sidebands as these have a negative impact on imaging and sound stage.  Again, this is something that is never discussed, but very real."

Hello ctsooner,

     I agree that 2 subs, when properly positioned, will produce better bass response in almost any room than just a single sub.  This has been scientifically proven with the stipulations that good bass response will exist only at a predetermined listening position 'sweet spot' that results only if a specific sequential sub positioning process is followed. This is the proper positioning procedure:

1. Place sub#1 at your preferred listening position and play music with good and consistent bass content.

2.Starting at the right front corner of your room,walk slowly counter-clockwise around the perimeter of your room listening for the exact spot that the bass sounds the best to you.

3.  Place sub#1 at this specific location.

4.  Place sub#2 at your preferred listening position and play the music with good and consistent bass once again.

5.  Starting at the newly positioned sub#1, continue walking counter-clockwise around the perimeter of your room listening again for the exact spot where the bass sounds best to you.

6. Place sub#2 at this specific location.

7. Sit at your preferred listening position and verify the bass response sounds 'excellent' to you; smooth, detailed and natural without any over or under emphasis.  If the you perceive the bass response as 'excellent', then the positioning process is completed.    If not, it is worthwhile to repeat the process since even small errors in positioning can result in less than optimal results.
     With only 2 subs, this process provides excellent bass response.only at the listening position because the positioning process has resulted in no bass standing waves at the listening position. There are no bass peaks (exaggerated bass) or nulls (lack of bass due to cancellation) at the listening position.but standing waves will still exist elsewhere in the room. 
     Following this procedure with a 3rd sub will significantly reduce bass standing waves (improving bass response) elsewhere in the room and adding a 4th will  eliminate the majority of bass standing waves in the room.  In other words, adding the 3rd an 4th sub will not further reduce bass standing waves at the preferred listening position but will elsewhere in the room.  It's the user's choice concerning the extent of state of the art bass they want in their room.  
     I wanted excellent bass response at all 6 of the seats in my combo 2-ch music and ht living room system even though I could only optimize the midrange, treble and sound stage illusion performance at my preferred listening position.  I realize, of course, that not all users will require excellent bass response throughout their entire room.
     Also, I definitely disagree with your statement that "2 quality subs with room EQ will trump most 4 sub systems".  It's my understanding that the only benefit of room EQ in a bass system is to reduce 'room slap' which is typically produced by a sub bass sound wave bouncing/reflecting off a hard floor and then  reflecting rather quickly off the ceiling or wall, causing a sharply perceived sound resembling a slap. 
      The frequency is usually below 300 Hz and often below 100 Hz.  Reducing the offending frequency via a room EQ may reduce the slap affect but will also affect the flatness and accuracy of your bass response in that frequency range; likely more noticeable the higher the offending frequency is.  
     The main reason your statement that "2 quality subs with room EQ will trump most 4 sub systems" is so inaccurate, however, is that a properly set-up 4 sub bass system  requires absolutely no expensive bass room treatments/traps, mics, room equalization and room correction software or hardware. 
     It is a very elegant, almost magical, solution for SOTA bass response in virtually any room and integrates extremely well and seamlessly with any set of main speakers.  It will go as low as the musical or ht content calls for in an effortless manner while still keeping pace and integrating well with the fastest planar-magnetic and electrostatic panel speakers.
    Here's a review of the Audio Kinesis 4 sub system from The Absolute Sound for a more independent and perhaps less biased source: 
http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

Tim

" We are also talking a more wife friendly room (I too like a cleaner looking room now days).  Another problem never mentioned is when the subs have drivers pointing into the listening space or ports the sidebands as these have a negative impact on imaging and sound stage.  Again, this is something that is never discussed, but very real."

ctsooner,

     Sorry, I went on so long on my last post but forgot to address your final points concerning the WAF and imaging:

WAF- If you view my system photos you'll notice it still maintains a clean look in my 23 x16 ft. room that my wife and I also enjoy.  The 2 subs along the front 16 ft. wall are hidden from view by each of my large 6 x 2 ft.panel  mains.  Each sub along the 23 ft. long side walls are a bit more visible but, because the 10" drivers face the wall,all that's visible is the nicely finished wood  on the sides, top and backof each sub.  My wife says these look like art gallery pedestals and she usually has a vase of fresh flowers on one or both.

Imaging and sound stage illusion-  If you care to read about this I discussed it thoroughly in my post on 6/13 responding to bo1972,  The gist is that, IMO, both are only enhanced with the Audio Kinesis 4 sub configuration that is rated at -3db @ 20-100 Hz.

     The Vandersteen Sub Nine is rated identically as -3db @ 20-100 Hz.  I know the Audio Kinesis Swarm/Debra, and I believe the Vandy, are designed to be -3db to compensate for the typical bass room gain of +3db.

Tim

Bass room gain?? Bass is all over the map in any room but an anechoic. ±30db is not a typical.

A multi-sub system may smooth out level, but it will be a phase nightmare. Imagine a rectangular box filled with water. Drop in a pebble. The wave will bounce around dependent on wall reflectivity. Add additional pebbles and interference patterns develop in the primary wave.

Subs that connect to speaker terminals do not 'take on' the main amp character. They add their character to the main amp.

"Subs that connect to speaker terminals do not 'take on' the main amp character. They add their character to the main amp."

ieales,
Talk to Richard Vandersteen about that topic and he will 'educate' you.

No need. I can do the math.

Certainly the load the main amp sees can influence the sound
jn a properly designed system such as Vandersteen the transfer function of the main amp is preserved, the sub amp is optimized and power factor corrected to properly drive the sub and present a fairly benign load to the main amp
most people think the sonic virtues outweigh any small math issues....

@ieales   What cred. would you have to "correct" Mr. V.?  😯

     When did Vandersteen start positioning, considering and pricing themselves as an ultra high-end company?  I've always considered Vandersteen as a solidly high-end manufacturer that offered very good quality speakers, subs and related crossovers at  more reasonable prices,especially considering  their proven history of high quality offerings.
     I was just checking out the new Sub Nine on their website.  I haven't heard them but from their description and look, they certainly seem like another fine Vandy product.  But I was a bit shocked by the $18,900 per pair suggested retail price.   The very fine Model Seven MKII are also very expensive at $62,000 per pair.They  are now even selling a pair of 600 W@ 4 ohms mono-block amps that have tubed input stages and bipolar transistor output stages (M7-HPA) for $57,200.
     So, if you want the best all Vandy system while optimizing in-room bass response, you'll need the Model Sevens, the matching mono M7 amps along with the extra pair of Sub Nines to optimize the bass response.  This will set you back $138,100 but you'll also get a pair of nice Audioquest  cables gratis.
     Undoubtedly an excellent audio system in almost anyone's estimation but not the better performance than expected for the price that I remember when I was speaker shopping in the early 1980's and auditioned the 4C. 
     I'm not sure if anyone on this thread is seriously considering the Sub Nines but I cannot understand why anyone would pay $18,900 for 2 subs when they could buy the Audio Kinesis  Swarm or Debra bass system with 4 subs that will likely provide better in-room bass response for $2,500 and save $16,400 in the process.  Yes, the Nines may produce more bass but I've never had an issue with the bass quantity ( or quality) with the Audio Kinesis.
     It's similar to what I recall from past Vandy products:; a product that offers better than expected performance  based on the reasonable price. . 
     Anyone know why Vandersteen decided to move away from these type of products, like their former 4C speakers, and toward the more expensive and esoteric?
Tim    

My guess is Richard has realized, through R&D, very significant improvements in the sound quality of his offerings over the decades and has decided to go for the ne plus ultra to see how good the realism of his designs can get. Listening to the Treo CTs daily, I need to hear the Model 7 system to realize how far he has been able to refine his design concepts. As is so prevalent among many successful audio designers, Richard is reaching for the stars. Of course, in result of this lofty pursuit, those of us downstream, benefit from his efforts as he incorporates the lessons learned into his more modestly priced offerings.

I believe that speakers like the 1ci's, 2ce sig. II's are what really keep Vandersteen in business. But like all designers (and RV is no exception) like to see what they can accomplish with no price constraints. That dream, that pursuit, of what can be possible within the scope of their expertise. And yes, they can justify this thinking with the "trickle down effect" to their more affordable products. This has been evident thru the years with the steady improvement of his core products like the models 1, 2, and 3's. Making great highend speakers like the Treo Ct and the Quattro Wood Ct have brought a lot of what goes into the Ultra high end speakers he makes to a more affordable whelm of gear.

In case it wasn't yet mentioned, the Sub 9 is not Vandy's only subwoofer.  The 3W series is replacing the 2W series.  While not inexpensive, it is much less expensive than the 9 Sub.  The 9 is intended to augment the Model 7, for the most part, and is priced accordingly.

@hifiman5 
Only a proselyte would believe that it is possible for a dumb amplifier to change characteristics based on it's driving source. If that were possible, changing any of the 'perfect' electronics in our systems would hopelessly dependent on its upstream device.

In the Vandersteen 2ce II, the impedance doubles from 4Ω to 8Ω between 35 and 75Hz, dropping to a nominal 6Ω @ 200Hz.

The output of a tube amp transformer will be a non-linear voltage driving such a load  as can been see on any Stereophile tube amp review.

The Vandersteen sub amp is a voltage driven device, as are most amps. When the voltage rises the output of the sub will also rise. What results is a doubling of the bass output @ 35Hz vs 75Hz. This would not occur with a tube amp driving a loudspeaker.

Another issue I never considered a good design was the passive XO with limited adjustment. In all but a limited number of amp input impedances, the frequency will be sub optimum possibly varying by as much as half an octave. It's been my experience that as little as 10Hz can have a significant effect when tuning a sub into room. A fixed frequency sub may work well in the lab, but may not elsewhere.

ALL MANUFACTURERS MAKE CLAIMS. As consumers, it our task to separate the buckwheat from the b...s...

@mr_m  Well said!  I recently had my McCormack DNA-1 upgraded by Steve McC at SMc Audio.  Upon discussing the prospects of upgrading/rebuilding my amp, he told me that some well-heeled clients afforded him the opportunity to design some ultra amps. He was able to take some of what he learned designing those amps and trickle them down to his SMc modifications and that my amp. would benefit from such. Exactly the same mentality as RV who loves to push the limits with the Model 7s and then bring some of what he learns down to the lower end of the line.  I agree with your assertion that the Model 1, 2, 3 designs are the bread and butter of his company as all of those speakers deliver great sound for the price and accommodate to diverse listening tastes and listening spaces.  For those who are ready to move up the line for an even more refined listening experience the speakers are there to be had.

@ieales  I guess you straightened Mr. Vandersteen and I out.  Thank God someone did!😯

ieales,

Since you have now claimed to have blown holes in all of Vandersteen's theories in subwoofer design, what would you suggest to be correct????