Why the fascination with subwoofers?

Few "full range" speaker go much lower that 40hz. That is a whole octave missing. And a subwoofer designed for home theatre is not what most audiophiles want.  They want one that plays music convincingly.  In fact home theatre speakers are not what audiophiles seek either.  Now there are true full range speakers, but they are typically very expensive and quite large.   Often a good subwoofer paired with high quality monitors will be a good option, even preferred by some. 

low E on a 4 string bass is 41hz.  A lot of speakers can't even go flat to 40hz.  Low B on a 5 string bass is 31hz.  Lowest frequency on a piano is 27.5 hz. 

Ive never hooked up subs and dont feel I’m missing anything. Different speakers bring different results and it just seems somehow obvious when any part of the sound spectrum is not quite right and time to move on to another speaker. Had some Monitor Audio one time and dont get the attraction there. In my system at the time at least. Thin and a bit etched. My Harbeths are all around a good sounding speaker. I suppose for home theater some may want that all enveloping sound of the lower frequencies ... I never got into home theatre,, Just doesnt interest me but can understand why some do.  @kink56   what you are saying  does makes sense and I have to admit I've always wanted to check it out.   Dont know that I will anytime soon.  

I have a pair of 12" sealed subs playing mono and been wondering about adding one or two more with the goal of flattening at the main seat. Would love to know your take on this.

I'd give it a shot. I don't use the Swarm but if I had it to do over that's the route I'd likely take. Duke is working on a sub system for me though- one that is integrated into a coffee table. It will be used to break up the standing wave in my room.

1 - Agree that subwoofer integration in a system can be difficult/problematic

2 - I'd rather have a speaker that goes accurately down to 40 than a full range that is less accurate. Martin Logan has achieved integration of a cone woofer with an electrostatic panel at least once - the original Monolith, and it was hugely expensive and still only went down to 35 hz. I prefer my CLS, which are a bear to drive (~83 db/1w) and dip to 1 ohm, even though they are 3 dB down at 40 Hz - you won't find a more accurate speaker

3 - I have other speakers that integrated a subwoofer, with separate powered crossover, separate amps and push pull drivers that are 3 dB down at 23 hz. They were expensive in terms of cost and in terms of requires amplification.

4 - I also have speakers in my main system that are capable of low bass without multiple amps etc. - 20 hz 3dB down  Ideal, expensive of course, but a complete solution without worrying about system integration.  I use them as the main speakers for video as well as the only speakers for audio, but I also have a couple of powered subs that are 3 dB down at 16 hz used only for video.

Out of curiosity, I hooked them up in the main audio system to see if there was anything missing, and can say that  with few exceptions (organ recordings that have content from the low C pipe (32') of a full sized organ, which is 16 hz, or a rendition of the 1812 Overture using real cannon fire) You aren't missing anything if your speakers can go down to 30 hz or so (remembering that you only hear down to about 20 hz and below that you are feeling it).  Bear in mind that the lowest note from a bass guitar is 41 hz, or from the low A of a concert grand piano at 27.5 hz.

My conclusion - by all means play around with subwoofers if it pleases you, but IMHO it is better to have an accurate system that won't reproduce the very lowest notes than one that will, but at the cost of poor integration between sub and mains.

Final comment - I find it amusing/ironic when stereo addicts worry about having speakers that will accurately reproduce notes lower than is contained in 99% of music  but end up buying what are essentially low base rather than true subwoofer add-ons (and some of them are listening to ipods most of the time).

This thread is well worth reading (this subject keeps coming up again and again).

https://forum.audiogon.com/discussions/hz-how-low-for-full-range-music

While it may be that some subwoofers don't integrate well in stereo mode, this has not been my experience with REL subs, have owned a number of their models, favorite is the TZero which is my current model, they make every speaker I have sound better.

psyco P I totally agree with you. I think the subwoofer thing is a big step in the wrong direction. I sincerely believe most listeners are not satisfied with the sound of their systems, and they mistakenly believe that what is missing is " the bass "  

kink56,

     The real strength of a 4-sub distributed bass array system is with musical content. There are 4 subs with 10" drivers strategically positioned around the room, driven by an abundance of power with the sole responsibility of reproducing bass frequencies between 20 Hz and whatever the crossover frequency is set at.
     The result is very fast bass which is very smooth, detailed and agile.   There's also the added benefit of very good bass dynamics due to the ample power reserves. 
     Prior to using the AK Debra dba system, I was unable to seamlessly integrate very good deep bass response with my fast Magnepan 2.7QR dipole panels with either a single or dual subs.  I perceived that bass as a bit lagging and disconnected. I believe the nature of the bass produced by good dba systems will allow them to be seamlessly integrated with virtually any pair of main speakers.
     The fact that 4-sub dba systems are also excellent for ht use is just  icing on the cake.

Tim

Sorry everybody, I posted this morning after the first page and not at the end of the thread.
This is a very timely topic for me as I am about to buy some new speakers. I have listened to both the Vandersteen Treo CT and the Quatro Wood CT at Audio Connection in Verona NJ. I was very impressed with both. These demos however were performed using John Rutan's house Aesthetix amps.
My amp is a Pass X-250.8. It is powerful and has very good bass control. I would love to bring it in and demo the speakers with my electronics but the problem is that it's so heavy to put in the car along with my pre and drive for 1 1/2 hrs to Audio Connection to do a more proper comparison between the two speakers. Also, my wife and I will be moving in a couple years when she retires so my listening rooms will change over time.
My two questions are:
1) Is it better to get the Treo CT and add a Vandersteen sub that can be positioned in appropriate locations as we move or just get the Quatro CT and not bother with subs?
2) What's the consensus on adding an AR REF 6 pre in the future to compliment my Pass amp, or could anyone recommended a different similarly priced preamp?
Thanks so much for any advice.
Bruce

Why do you think you will need a subwoofer with any of those Vandersteens that you auditioned at Audio Connection? I use a subwoofer with my small stand mount speakers that only go down to 75hz. I would think those full range Vandersteens would not need a subwoofer!

I am a former AudioKinesis owner and really respect Duke's work. His Swarm is a great system. I took a similar path as I wanted smaller drivers and boxes. I use 8" drivers in 0.4 cu. ft. sealed boxes. The four boxes sit at various spots in the room. I use a Beveridge RM-3 active crossover with LP and HP boards cut at 100 Hz, Linkwitz-Riley 4th order 24 dB slope. Amplifiers for above 100 Hz are either Atma-Sphere or Music Reference, the bottom a vintage Luxman. I use this set up with my ESLs and box speakers and all I can say is I wish I did this a lot sooner. I can't see going back.

@brskie,
I own the non-CT Treos, and have 2 2wq subs. I am very happy with the combo. So much so, I will probably get the new Sub 3's when I sell the 2w's.
If it were me, first I would ask Johnny.
Barring that, I would think getting 2 Sub 3's with the Treo's might possibly be a smidge better than the Quatro's(as you can distribute the bass within the room)- Only if you have limited room/placement options-which is my problem.
The Treo's are a tad smaller than the Quatro's and I can place them easier in my cluttered LR/DR.
As far as amps go, the Pass should be a nice match. I have no experience with AR.
One thing I would offer is that Vandy's like zero feedback amps.
I use Ayre and Atma-Sphere.
Bob

@yogiboy ,
Vandies don't 'need' subs, but having them really fleshes things out, subtle but noticeable. Quatro's have built in subs with equalizer.
B

If you can hear the sub, then it's too loud.  A good friend of mine always has his up a bit, and he complains that he cannot hear mine.... but you sure miss it if I turn it OFF.  In my studio I run stereo 15" subs... they make great monitor stands, but they do not call attention to themselves unless the music demands.   

Hello hifidream,

     Congratulations on creating your own custom distributed bass array system for your Magnepan20.1 speakers.  I know the 20.1s have very good bass performance in stock form with 2 large planar-magnetic bass panels in each speaker that all output down to 25 Hz.  Not full extension to 20 Hz like many good subs but close and very respectable.
     Counting each pair of bass panels as a sub,  I would suggest you're actually using a total of 6 subs in your room/system.  While 2 aren't outputting bass that's fully extended, they're both outputting the exceptionally fast, articulate and smooth bass provided by planar-magnetic panels down to a deep bass level of 25 Hz.  

      Since we've both experienced the amazing seamless integration with even fast planar-magnetic panel speakers (whether mid-level models like mine or top of the line models like yours) and the high quality bass produced using  4-sub dba systems, I think it's safe to assume you'd agree that the dba concept works exceptionally well.

Tim

hifidream,

     I forgot to ask a few questions about your custom dba system in my previous post.  I hope you don't mind, I'm just curious about a few things:

1. What brand and model were the initial 2 subs you added to your system?
2. What brand and model were the last 2 subs you added to your system?
3. Do you operate your 20.1s full-range or limit their bass output?
4. What upper cutoff frequency are your subs set at?

Thanks,
  Tim

Dear @millercarbon and friends: You are rigth about that full range speakers down to 20hz not only are expensive but don't realy gives the " rigth " low bass not only to 20hz but almost does nothing for below 20hz frequencies that exist in the recordings.

The first problem with those " 20hz " speakers is that are working through electronics ( amps ) that was not designed to fulfill the specific needs of those speaker woofers , there is no " total control " down there with universal amps and if those amps are tube electronics the problem is worst.

Other problem is the frequency response that those woofers handled by design, normally goes to 150hz to even 350 hz depends the overall speaker design.
When the recording signal ask to reproduce a 20hz frequency those woofers at the same time must be reproducing other way higher frequencies/harmonics making the the IMD goes really high making a damages to all the system frequency response at the seat/listen position.

In my point of view and along the other disadvantages that others of you already posted " against " full range speakers in reality is a big mistake to invest on it.

Even those full range speakers can be up-graded with a pair of self powered sealed subs working in true stereo fashion where the full range speakers will be working as a satellite part of the room/speaker system.

I agree with @noble100  that low bass is a separate music reproduction signal and mid range/highs an independent signal reproduction system.

I already posted in other thread the next link that's a scientific papers made it by Harman International where they stated all what we need to learn about the use of subwoofers in general and for home systems:


https://pdfs.semanticscholar.org/00da/51387c572cfd27c0256cb15e44e976a1a72e.pdf

coming from that link we can read:


"  Four subwoofer at the wall midpoints (configuration 11) was the best practical configuration in terms of MSV. Two subwoofers at opposing wall midpoints (configuration 6) was nearly as good and also offered stronger low-frequency support. Configurations with more than four subwoofers were not found to be advantageous, especially when cost is factored in. These results appear to be generalizable to reasonably dimensioned rectangular spaces [19] . ""


They are not talking about wired stereo or mono.

So at our seat position normally two subs are enough and I'm for sealed subs designs against open/reflex ones that gives some problems on way up resonance frequencies. If you takes the Wilson Alexandria or MAXX 3 bot that goes to 20hz have that problem and both are reflex designs.


I can't remember who speaks in the thread about the integration of very fast ribbob/electrostatic speakers with " slow " subwoofers and here an explanation about that tells us does not really exist that " slow " bass subs response other that the one coming from each instruments:


http://www.soundstagenetwork.com/maxdb/maxdb061999.htm


The other subwoofers " main approach " to even or disappears standing waves in the room in reallity are not the main targets for add a pair of subs but to put at minimum the overall speaker system IMD kind of distortion as I already talked here:

https://forum.audiogon.com/discussions/do-you-think-you-need-a-subwoofer/post?postid=310058#310058

the other main target is that the low bass system " management " if we do " perfectly " always we will have a way better whole room/system frequency response due that are the low bass range and its developed harmonics whom tame and put the overall signature at the mid range and high frequency range.
The low bass range is the frame of what we are listening at our seat position.

So as better room/speaker system low bass range as better quality whole room/system levels.

As a " side " advantages adding subs gives better low bass quality, deeper low bass, tigther bass response ( less overhang. ). When I said deeper low bas I'm not saying down to 20hz only but even lower that that where belive it or not exist more information that what we could think.

In other thread I said the importance that the subs it self can comes with a truly low THD at 20hz and 100db SPL, mines around 0.5%. One gentleman there tolds that is not important if the response is evenly in the low bass but I think that we can have evenly bass response with low THD and evenly bass response with higher THD. Maybe I'm wrong but if I was any one of you I always will look for a low THD for my susbs: this is a good place tostart along sealed kind of design.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

I bought the Focal Sopra No 1’s knowing they would be light in the bass region.  Just picked up a pair of JL Audio F112 suns with custom floor stands.  Wow!  I had an old Definitive Technology sub before but having two subs of much higher quality makes a huge difference.

@atmasphere 

I'd give it a shot. I don't use the Swarm but if I had it to do over that's the route I'd likely take. Duke is working on a sub system for me though- one that is integrated into a coffee table. It will be used to break up the standing wave in my room.

Interestingly, my additional two subs would go disguised as coffee tables as well. 

Ok, so you don't use swarm, but I take you are replicating the concept: distributed bass array playing a mono signal. Is the goal to minimize SPL variations at different seating locations? Or to optimize at the prime seat?
How did you determined you needed to break down a standing wave?

Regards

Ok, so you don't use swarm, but I take you are replicating the concept: distributed bass array playing a mono signal. Is the goal to minimize SPL variations at different seating locations? Or to optimize at the prime seat?
How did you determined you needed to break down a standing wave?

The goal is uniform bass response in a greater portion of the room including the listening positions. I've done lots of setups over the decades as I've been doing audio shows since the late 1980s; so the answer to your third question is 'experience'. Standing waves are a common problem in a lot of rooms. One time we used an Accuphase room correction device but quickly learned that it can't do anything about a standing wave. If one is present, you can put as much power into it as you like and at the null point the bass still won't be right.

So the elegant approach is to use a distributed bass array system like the Swarm, which is the best example out there.

Do you have to play a mono (i.e., summed) signal from all the subs or would there be value to trying the front subs in stereo and the rear subs or one rear sub in mono to better deal with standing waves?

@atmasphere 
Ralph: if I'm taking measurements and measure a deep valley within the subwoofer frequency, would that be pointing to a standing wave?

@mitch2 
While many records have very similar low bass recording on both channels, to be certain it works you should play a summed up mono signal to achieve this.

mitch2,

     It was mentioned earlier that humans are unable to perceive true stereo in the bass frequencies below about 80 Hz.  Even if you were an exception, there's the problem that there's virtually zero musical content recorded with discrete L/R bass signals.  I'm aware of none in cd or lp format.
     I run my 4 subs in mono mode because of this.  As I've stated before, however, I do perceive the bass as stereo in my system on well recorded cds and 24 bit/96 Khz FLAC files even though I believe the bass is summed into a mono signal.  By stereo bass, I mean I perceive the bass as originating from the proper position within the sound stage illusion.  For example, the kick drum dead center and the upright bass a few feet forward and a few feet left of the kick drum. 
     I can only explain this by assuming that the higher harmonics or overtones of the deep bass fundamental notes's frequencies extend beyond 80 Hz and are being reproduced by my main speakers, giving my brain the clues it requires to associate the higher directional harmonic frequencies with the much deeper and non-directional fundamental frequencies reproduced by my bass system and determine the specific locations of the bass instruments.
    In your situation, since there are no recordings with discrete L/R bass channels, locating a sub in the middle of your back wall and running them all in mono would give you smoother bass that you'll perceive as stereo bass.  Adding 2 more subs, running all 4 subs in mono and positioning them where they sound the best to you will provide the smoothest, most natural, most dynamic and effortless bass that you'll perceive as stereo bass.  I'm almost certain it'll provide the best bass response you've ever experienced and it will provide sota bass response throughout your entire room, not just at a single sweet spot. 
     I can share a best practices method to optimally locate each of your 4 subs if you're interested.

Tim

Look, small bookshelf speakers begin to work effectively from 120-150Hz. I mean really flat characteristic. There are different reasons for it. So, subwoofer mast work to 160-180Hz in this case. Just if you install it at center between the main speakers, bass and main signals can look "separate". And the negative effect is just stronger if the subwoofer stands somewhere in the corner. The best idea is to use main speakers working at least from 40-50Hz and subwoofer just to 60Hz. There is another way - you can have small main speakers and TWO subwoofers, one for each channel. They must be installed under the main speakers. It is possible to buy not expensive devices (about $200 each) produced by PolkAudio company.
Vlad

Do you have to play a mono (i.e., summed) signal from all the subs or would there be value to trying the front subs in stereo and the rear subs or one rear sub in mono to better deal with standing waves?

I'd put the side subs in mono. That's the plan in my system since my speakers already go solid to 20Hz.

Ralph: if I'm taking measurements and measure a deep valley within the subwoofer frequency, would that be pointing to a standing wave?

That would be my first suspicion!
 

For example, the kick drum dead center and the upright bass a few feet forward and a few feet left of the kick drum.
     I can only explain this by assuming that the higher harmonics or overtones of the deep bass fundamental notes's frequencies extend beyond 80 Hz and are being reproduced by my main speakers, giving my brain the clues it requires to associate the higher directional harmonic frequencies with the much deeper and non-directional fundamental frequencies reproduced by my bass system and determine the specific locations of the bass instruments.

Yup- that's exactly how it works.

Dear @lewinskih01  :  First than all you ask to a man that's a seller always. That person not even has in his system that four subs array but already making  advise about and telling stupid things like that : " that's exactly how it works ", and this with out first hand experiences in his room/system. I don't care that he is a tube manufacturer because this at the end means almost nothing on what we are talking here. Audio kinesis is a seller too.

Of the people that I know is not a seller and has first hand experiences with more than two subs is noble 100 and he has no interest to sell you or at any one nothing but only shares his first hand experiences.

Btw, that tube manufacturer a few months ago posted in a hot discusion with me in the analog forum that he did not needs subs in his system because he has a very good system response down to 20hz with passive speakers. Obviously he has no idea about and even today he does not knows what's talking on this specific low bass/subs management and he will know when he finally has first hand experinences at his place, not before.

Measurements always can help but if I was you or @mitch2  I must ask my self:

with the two subs I have and at my seat position have I good low bass perception: tigth, full, no resonances, no overhang and pristine definition on that range and great midrange/highrange performance?

if the answer is yes then we have to add nothing, two subs are more than enough and if yes then that means that the subs location is just rigth. Will improves in remarkable way adding two subs for a way better  quality performance at my seat position?, maybe you even can't say was a true up-grade. With low bass your ears will know all about if you know how low bass  performs in a live event seated at near field position. If we don't have this kind of experiences then we need ( a must to ) to live that experiences before any move /action regarding low bass/subs. It's up to each one of us.

If you need more than a one listening seat position the a third or four subs could be better but even with 2 subs maybe you can ( ? ) do better  moving a little your subs today locations, not drastically, only little movements with. Additional you always can use a parametric eq. for those subs and all these before adding two more subs.

At the end the " move/action " we make belongs to each one of us.

I like the Harman white papers because are an abstract work/research/modeling that try to sell nothing only sharing first rate information about.

Here two links that can help all of us:

https://forum.blu-ray.com/showthread.php?t=48286

https://www.bringtheruff.com/using-multiple-subwoofers-to-smooth-bass-response/


@noble100 , I already " finished " my tests on that low bass stereo/mono recorded or not and the response on what we are listening. I will post about in the other thread following our dialogue.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

LOW bass is pretty cool for HT. I became obsessed with getting 20 hz extension in my 2 channel room and a couple of the big hitters couldn't give me anything below 40 hz even tho JA's measurements showed both these speakers were capable. I brought my big a$$ dual side firing 12" sub into the room and within a half hour I was getting smooth flat measured bass all the way to 20!  All that experience showed me was my can lighting and duct work is noisy and I brought the sub back into the tv room.Now i'm happy with 40 hz extension and find more is less when it comes to deep bass and music.

@rauliruegas 
Not sure why you are attacking atmasphere. He's not selling subs. Over the years Ralph has been as unbiased as I can expect from a manufacturer, even when explaining benefits of a SET, which is a product that competes with his amps. His experience is relevant to me.
Also you are taking words out of context. When he replied " that's exactly how it works" he was answering why subs added depth, etc, which is something I knew too - but the question wasn't pointed to me.

FWIW, over time I've exchanged with several knowledgeable people who do sell subs and don't, listen to their points of views and explanations to help form my opinion and then decide how to try it out myself.

BTW, thanks for the link to the Harman work. I'm familiar with it as I have Floyd Toole's Sound Reproduction. One material aspect of their research was time delay between the subs in the room, which is something I can't do with my setup. Neither can the SWARM system, yet Noble100 and Millercarbon report very good results, so I'm intrigued. In fact mine are Rythmik subs with more tuning flexibility so should do even better. And I do have means for proper measurements.

Regards

Do you use a bus to fly to Chicago? 

Oh and the Swarm system is a bad joke. The people who thought this up have no understanding of acoustics in a usually sized room. It is all about reducing first reflections. All the swarm system does is increase the number of first reflections. The result is mud. It may be powerful mud but mud none the less. 

Really? And you would know..... how? 
Which ones have you heard?

lewinskih01

One material aspect of their research was time delay between the subs in the room, which is something I can't do with my setup. Neither can the SWARM system, yet Noble100 and Millercarbon report very good results, so I'm intrigued.

My 4 are run with two Dayton amps, giving me the option of running stereo, mono, and with variable phase on either one or both pairs, in addition to being able to wire one or more completely out of phase. Phase isn't exactly the same as time delay, but close enough for government work. 180 degrees out of phase equates to a .025 second delay at 20 Hz. 

In any case what little I've had time to experiment with hasn't turned up any noticeable difference. Yet. This probably says more about my lack of experience.

The bass from a distributed bass array, it seems to me, is so much better than anything possible from any one or maybe even any two subs, that it takes quite a long time to appreciate. This is compounded by the fact its impossible to know where the really good bass is until you come across it, often by accident. Some recordings I always thought had a lot below what I was hearing turns out they really do. Some others not so much. Some I would never in the world have thought of having low bass surprised me. I've barely begun to scratch the surface of what's hiding out there waiting to be revealed.

Often times when it happens its not like you'd think. Almost all of what we think of as bass is guys plucking strings or hitting synth boom boom boom each note pretty much like the last. This I am now sure has more to do with the inherent inadequacy of a single sub than anything else.

Because the bass with a bass array is never like that. Each note, each drum whack, whatever, is its own unique event. And I know this is passing strange and one hell of a conundrum because at the same time its all mono its also precise and localized. Just not localized anything like the way people assume. Its clear the sense of localization has nothing to do with what is coming out of the subs.

Obviously, because I can run all 4 off the one amp and it sounds exactly the same as run in stereo. To be fair I noticed the same thing with my one Talon Roc sub. Which with its massive drivers and isobaric design ought on paper at least to be faster and cleaner than my much cheaper PartsExpress subs. But its not. Not even close. The 4 sub array is much more precise. Despite there being 4 of them. Spaced all over the room.

But because it is so much better I think means it takes a lot longer to dial in and understand. Also my time is limited and given the choice between enjoying awesome music and working to make it even better I keep coming down on the side of immediate gratification.

So sue me.

I'll get around to it, eventually. Even so its more than enough to know absolutely and for certain this is the way to go.

Those of you who think adding a sub woofer is just adding bass to a system are missing the point. A truly great sub woofer adds feeling and will not take over the system, it will just add what the mains are not delivering, and when this happens correctly with true integration the listening room is loaded by the sub and the whole room seems pressurized and the main speakers come more alive because they are now free to do what they do best...

Matt M

steakster
I moved my Talon Roc out to sell and have more room. But it turns out I have plenty of room. Soon as I can find the time its going back in. Mine's powered so I will be able to set it to do very little but add a little at the extreme low end. If it even will do that. Was never able to get it to go as low as my bass array does already, but then with one you are forced to locate it for least bad overall. So we will see.

Can someone define for me what "tight" bass is.

   clio09,
      I can only tell you what my definition of 'tight' bass is, which I realize may be a term that has different subjective meanings to others. A bit difficult to describe but easy to identify when you hear it.  
     Tight bass to me means accurate, solid and natural bass. The leading edges, the pitch and tone, the duration of the sound, the volume, the impact and the decay of the bass all are perceived as accurate and natural.  There's also no sense of exaggeration, attenuation, blurring or something added to or missing from the bass.  In other words, the sound of bass instruments sound right and tight, just as they sound when played well and heard live in person.
     I've also personally noticed that, if the musicians get too drunk, then you often don't get that proper degree of funk.

Tim

Thanks for all the links, it has given me a better understanding of subs and setup. 

Can someone define for me what "tight" bass is.

An artifact of sound reproduction. It does not seem to occur in real life. Punch but no detail, in a nutshell.

To address Raul's attacks against me: I don't sell speakers of any sort. I recently moved, and now have a standing wave in my new listening room. I've seen how effective the Swarm addresses this so I know they will work in my situation. I only need two, as my speakers go down to 20Hz no worries.

Dear @lewinskih01 : Only common sense. As I posted to you a few months ago that " seller "/atmasphere ( other time I will explain about that word " seller " because it’s no matters in this thread. ) said that his syatem goes down to 20hz no subs needs at all ( in that dicussion what we was discussing was that any passive speakers needs the integration of two self powered subs. ).

His answer ( what he posted in that thread. ) only showed his ignorance of the whole subwoofer/bass management because even his field coil speakers and his system will be improved through the addition of two self powered subs not 4.

Suddenly in this thread he gaves opinions as if he really been a true expert on the whole subject when even today he has no first hand expeiences in his room/system with subs, go figure. From where he already knows for sure what is posting.

I’m not attacking him but only disclosing those facts. That he be a tube electronics manufacturer does not means knows everything about everything in audio because at least in the subs/bass management whole subject it’s ignorant as you, me and any one else are ignorants on several subjects/topics in audio.

Look, I took around 1/one full year to integrate my subs in my room/system. A full year with " thousands " of tests till the subs were very good integrated to.

More than 16 years ago I was thinking exactly as atmasphere that because my ADS L2030 speakers goes down to 18hz I just do not need subs in my system.

I was totally wrong and was till I try and learned about subs that I added to my room/system and igf you look to my subwoofer thread that I posted in the analog forum its date is 2005, this is almost 14 years ago.

The first discovery for me was not if my system bass was now " rigth " but the paramount differences ( for the better ) that makes that I put at minimum the IMD of my ADS L2030 and till today I still think is the main improvement followed by all what we subs owners already experienced with.

No one can try to shows him self as a knowledge man just reading with out first hand experiences in his room/system.

Btw, for me makes no sense to have 3 or 5 bass evenly in any room/system because for the mid and high frequency range exist only one " rigth " seat position no matters what.
What we have to take care in deep is that at our room/listening seat position the bass, mid and high frequency ranges stays spot-on and that’s it.

Two subs are enough to acomplish that. Harman tell us in precise and scientific way: 4 are the ideal but two are enough. Ideal for more seat positions but 90%/95% of the quality performance levels we can accomplish with two subs, yes it will takes a little more time to do it but we can do it.

No, not one full year as I took where the main reason wa that I was totally ignorant on the whole bass regards and I did it alone with no advisors or the like and really was a huge learning lessons because I learned several other audio subjects other that the bass management.

I know that you already has very good knowledge levels with the subs but for new comers about this link could help:

https://www.audioholics.com/home-theater-connection/crawling-for-bass-subwoofer-placement

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

and he still posting that he needs only two subs because his speakers goes down 20hz ( solid hz. ): so what?, that confirms that he did not understand yet the overall subject in this thread and in the reality of any room/system.

Dear @bdp24  : You are rigth, live event experiences is a must to have and understand the home system bass management.

We need ( as you already have. ) first hand experiences trhough live event experiences seated at nearfield positions ( in different venues. ) to try to approach that live bass experienced.

We always will be not even near the live experiences but at the end the end our target must be to " approach " it.

Maybe the bassm management range in home systems is the most complicated target to achieve in the best way we can. Always will be trade-offs where we have to choose in between.

R.

What bdp24 said, +1. Get around a rhythm section(within 25 feet), that’s played together for any length of time and you’ll understand, "tight Bass". For(most) anyone that’s been around the real thing, for any length of time, it’s mandatory in the listening room. Far as semantics: "tight" generally refers to how cohesive a group sounds. When applied to a system (in my personal thesaurus, anyway), how well the lowest notes are detailed and how easy it is to follow each rhythm section player’s individual lines(given a well mixed/mastered recording, everything in phase and balanced). Then too, there’s the recording venue’s ambiance info, much of which is carried in the lower registers. ie: Dead Can Dance(Spirit Dance/Yulunga, especially) can place one in the Quivvy Church’s auditorium/studio, with the right setup. When I first built my woofer system, it was designed(1980-81) to mate well with my Acoustat Model IIIs. It’s worked seamlessly, with everything(mostly planar) I’ve owned, since(various active crossovers, amps and one driver change, but same transmission line cabinets).

I have to admit that with my Magnepan 20.7's I have toyed with the idea of adding a subwoofer but in the case of the 20.7's in my room they measure flat down to about 28hz and only then start to roll off.  So I would not want to crossover the signal "from" the maggies to a sub, rather I would want to blend a sub in beginning at around that point of 28hz.  BUT of course there's just very little music down there I don't believe however.

@rauliruegas 
You are really mad at Ralph. Oh well...

FWIW:

and he still posting that he needs only two subs because his speakers goes down 20hz ( solid hz. ): so what?, that confirms that he did not understand yet the overall subject in this thread and in the reality of any room/system

I believe he's talking about the same approach Earl Geddes, Hartman, etc do: 4 sources playing subwoofer frequencies to flatten response across multiple seating positions. In his case, per his comments, his mains go down to 20Hz so they are playing in the subwoofer region as well. He will add two subs in parallel to the mains so he will end up with 4 sources playing subwoofer range. That's all. Common sense to me (coupled with some theory/knowledge). 

rauliruegas,

I don’t understand why you’ve been going after atmasphere/Ralph, either. Yes, his primary business is designing and selling high quality tube gear but it’s a mistake to assume his audio knowledge and experience is limited because of this.
I’ve been reading his posts for years and it’s obvious he has an abundance of knowledge on a wide range of audio subjects that I’m sometimes surprised by. For example, he knows Duke Lejeune, owner of Audio Kinesis that sells the Swarm and Debra 4-sub distributed bass array systems, and is well versed on the subject of attaining good bass response in rooms smaller than recital halls.
He’s been setting up very good sounding systems in small audio show rooms for years, often utilizing subs and dbas to get the bass sounding right in these rooms which is almost always very difficult to do.
His personal system speakers are capable of very good deep bass output down to 20 Hz but he’s still adding a couple of custom subs because he already knows through experience that this is the best method to further smooth and improve bass response in his entire room.
I’ve explained the above because it appears from a few of your posts that you’re unaware of Ralph’s breadth of knowledge and experience and the value many Audiogon members, including myself, place upon the information, opinions and advice he shares on a consistent basis.

Thanks,
Tim

pwhinson:
" I have to admit that with my Magnepan 20.7's I have toyed with the idea of adding a subwoofer but in the case of the 20.7's in my room they measure flat down to about 28hz and only then start to roll off.  So I would not want to crossover the signal "from" the maggies to a sub, rather I would want to blend a sub in beginning at around that point of 28hz.  BUT of course there's just very little music down there I don't believe however."

Hello pwhinson,

     I've only listened to the Magnepan 20.7s once (driven by either Boulder or Bryston amps at Audio Connections near Chicago) but still know I'd definitely already own a pair if I was only richer.
     I remember the sound as the usual great Magnepan midrange, treble and imaging  of their top model combined with a much deeper bass response than I was expecting.  It was not only well extended deep bass but incredibly high quality bass that was just as fast,smooth and highly articulate as the midrange and treble response, resulting in a seamless quality to the sound from top to bottom that was very impressive.
     You're correct that there's not a lot of musical content requiring reproduction of frequencies much below the 20.7's bottom limit of 25-28 Hz. 
     I'd only suggest adding subs to your system if any of the following is important to you:
1. A system that's completely capable of reproducing all humanly audible frequencies from 20 to 20,000 Hz.  While it's true that there are few recordings with deep bass down to 20 Hz, and if it exists it's probably summed L/R ch mono bass, there are some that do contain bass this deep (but not none on vinyl) and you'll only know it's there if your system is capable of reproducing it. There's also the possibility that new physical or downloaded music formats are introduced that allow for full range (20-20K Hz) recording and playback.  I have no advanced knowledge of any new formats but even some existing formats (like cds, blurays and hi-res digital files) are currently capable of full audible range recording and playback.
    It may also be useful to consider the types of music you listen to.  I believe only pipe organs, classical, some rock/jazz and electronica contain notes this deep. 
2. A system that is currently used for both music and home theater or you're considering using it for ht use in the near future.  There's an abundance of sound effects and even some music that has very deep bass content on ht content like regular and 4K bluray discs as well as many premium channels on subscription HDTV services.

     If either of the above is important to you, I believe adding subwoofers to your system would be beneficial.  I think you have 2 options if you're interested in extending and improving the already very good bass performance of your 20.7s.
     One option is to add 2 good powered subs of your choice and experiment with their positions in your room as well as the volume, crossover frequency and phase control settings on the subs until the bass sounds best to you (smoothest, most natural and most seamless integration with the 20.7s). 
      I suggest you use 2 subs, rather than a single sub, because 2 will provide faster and more agile bass that more closely resembles the bass supplied by your 20.7s as well as better smoothing and adding impact to the overall bass response in your room. I would also advise you to calibrate the best bass response for music because, in my experience, this will also work well for ht use, too. 
     Of course, the brand and model of the subs is your choice but I'll recommend a few that I think might work well in your system and room:

JL Audio F110- 10" long-throw aluminum driver, 1,200 w amp in a sealed enclosure, 13.5"W x 14.24"H x 16.51"D and 52.7 lbs., about $1,500 ea.

REL T9i- 10"  long-throw aluminum driver, 300 w amp in a sealed enclosure, 13"W x 15.2"H x 16"D and 41.3 lbs., about $1,300 ea.

SVS SB1000- 12" fiber composite driver, 300 w amp in a sealed enclosure,  13"W x 13.5"H x 14"D and 27 lbs., about $500 ea.

     I'm fairly certain the addition of 2 subs, properly positioned and configured, would prove to be a good improvement to your system's overall bass response for both music or ht. The major downside to this approach is that it would only extend your deep bass response to about 24-25 Hz.  You would clearly perceive a smoothing to the bass and additional bass impact but, unfortunately, no deeper bass extension.


     However, I'm certain that another option, a 4-sub distributed bass array (dba) system, would prove to be the greatest improvement to your system's overall bass response and, in my opinion, the best solution I'm currently aware of for supplementing and extending the bass response and integrating seamlessly with any pair of speakers, but especially with 'fast' and detailed speakers such as planar-dynamic and electrostatic panels. 
     I'm certain this system would work very well for your system because I've been using a dba system with my fast Magnepan 2.7QR speakers for about 4 years now.  I realize the 20.7s are far superior fast speakers than my older models, but the forces behind dba systems' excellent bass performance and integration work equally well with virtually any pair of main speakers.
     This system has worked so well for my system that I started a thread about it a few years ago, here's the link if you'd like to know more details:

https://forum.audiogon.com/discussions/anybody-else-using-a-distributed-array-sub-system

      Also, here's a link to an Absolute Sound review of the Audio Kinesis Swarm dba system, which is almost identical ( the Swarm subs are just a bit wider and shorter) to the AK Debra dba system that I own:

http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

     There are 2 options if you're interested in setting up a dba in your system:

Complete AK Swarm or Debra complete dba system- these include four 4 ohm subs with removable port plugs for either sealed or ported operation, each sub has a 10"aluminum long-throw driver, 14.5"W x 23.75"H x 10.375"D and 43 lbs., and a Dayton Audio SA1000 1K watt class AB mono sub amp that powers all 4 subs, about $2500 for the complete system.

Custom dba systems- these would involve buying 4 powered subs of your choice and positioning them asymmetrically within the room for optimum performance.  This is the most flexible method of creating a dba system since you can choose the quality of the subs used for bass extension and maximum spls. 

     Either AK dba complete dba system will provide flat frequency response from 20-100 Hz with a maximum output of 113 db at 20 Hz. The bass extension and frequency response performance levels of a custom dba system will vary depending on the exact subs selected.  The excellent bass integration quality with your 20.7s, however, will not vary depending on the exact subs selected and will remain constant.  Which means a very good dba system could be created for as little as $2,000 if 4 SVS SB1000 subs were used but an 'ultimate' dba system could be very expensive if very hi-end subs are used.  Considering this, either AK dba may be the best bargain given their high level of performance in bass extension, accuracy and maximum spl level.  

Sorry I wrote you a book but I wanted to give you as much info as I could.

Tim

Dear @lewinskih01 : Good that make sense to you but I think that you are losting a main critical premise/parameter/characteristic on the subs overall subject, been 2 or 4, and is that separated subs ( 2-4 . ) is the way Harman speaks and I additional posted that a main target integrating ( at least. ) two subs is to put at minimum the IMD levels in the main speakers and both targets, the Harman and mine, can’t be accomplished in the way your " common sense " says to you.

Got it the huge differences? 2 or four subs permits to place it in the ideal position for the room/system and the same time that the IMD in the main speakers goes way lower than ever.
You can't or maybe is almost imposible try to find out/playing with several positions of two subs along the main speakers woofers . Normally the main speakers mid/high frequency range we already has/set up in the rigth main speakers position and we can't make many position changes to see if the bass improves and with out lowering the main speakers IMD ! ! 

In the other side and again makes no sense to me follow talking of more than one seat position to listen a stereo room/system because exist only one seat position that is " rigth/correct " to listen spot-on the mid and high frequency ranges.
Who cares other than one seat position to listen it if really does not exist. Makes sense to you? or is that you only listen to the bass range? ! ? ! ? ! !

My post is not against atmasphere and again I’m only disclosing facts that he showed don’t understand very well yet. I’m sure that when he already have his two subs his way of think could be a little different or maybe not ? !.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Dear @lewinskih01  : but how can a universal amplifier design handled  woofers ( passive speakers. ) in better way that the dedicated amplifier on a self powered subs that was designed in specific to fulfill the woofer needs?

makes you sense too?

I'm sorry but now your last posts to me make no sense at all. Please don't lost or move from the subs focus/specific subject. Forgeret about atmasphere but not because you want to " deffend " it ( that tehre is no reason to do it because you have to deffend him for nothing because no one is against him. ) lost the main subjects in this thread.

R.