Why the fascination with subwoofers?

Dear @noble100 : """ All DBA systems will provide accurate, detailed, smooth and natural bass that has an effortless quality to it. """

as can do it non DBA subs system. As you said maybe a different way " to see things " but DBA is not the only or best option. Clearly is for you and other gentlemans but exist other very good alternatives to it.

Not only you but other audiophiles are running their passive main speakers in its full range way and I can’t understand yet why what @phusis and before him me posted here and in other related subs threads ( at least me. ) the main critical advantage when any one integrates two or more subs to his system using a high-pass filter that permits to put at minimum the main speakers IMD kind of distortions.

The rewards doing that with passive speakers is not some thing tiny, no it’s more significant perhaps that to have those additional low bass octaves. Of course that we can understand it only when we have that experience.

I posted in that linked thread that my main discovery when I integrated my subs to my system ( where my main speakers goes down to 16hz. ) was the overall " impact " that was developed by lowering the main speakers IMD kind of distortions. Yes I know your targets are different from pussin or mines but you must try it in some future time and if you test it then the XO point can be at around 80hz and subs wired in true stereo fashion.

I think that we can’t diminsh the IMD developed distortions by the main speakers no matters what if I was you at least I will try and if you don’t like it then always come back at the original status.

Normally the owners of planar type speakers are " against " to run the main speakers as a " satellite " one that is the " rigth " way to go ( for me. ) because that high-pass filter makes a paramount difference.

Yes, my high-pass filter is inside my 20.6s amplifiers where I don’t need to use any kind of external active/passive XO due that my amps are coupled by small caps.

Anyway is up to each one of us, only an opinion that can improve our daily MUSIC pleasure.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Dear @noble100  : I did not knew which is the crossover frequencies in your 2.7qr and now I find out:

Low-Pass 12dB/octave @ 650Hz

Band-Pass 6dB/octave @ 500Hz-950Hz

those " numbers "  makes me to tell you it's almost and " emergency " and your speakers are " shouting " for that high-pass filter ! !

Rigth now you have good bass and you can have an exceptional mid/high ranges in your system adding that high-pass filter.

IMHO it's a must that you do it because the IMD distortion levels is to high and in a very wide range up to over 900hz. It's a serious compromise to leave it that way.
A compromise is that you can have a better  quality " equilibrum " with your bass range if you can achieve better quality levels in the mid/high frequency ranges. As I said before is up to each one of us.

Btw:   you said that the CD's and other digital sources you own/use does not goes below 20hz. Maybe you are rigth but always exist a dude because your system does not have the ability to shows you if in reality goes only to 20hz or below it.

R.

rauliruegas:
"Dear @noble100 : """ All DBA systems will provide accurate, detailed, smooth and natural bass that has an effortless quality to it. """

as can do it non DBA subs system. As you said maybe a different way " to see things " but DBA is not the only or best option. Clearly is for you and other gentlemans but exist other very good alternatives to it."

Hello rauliruegas,

     Yes, it's definitely possible to attain very good bass response using 1 or 2 subs.  As we've discussed previously, this is a bit of a compromise since the 1 or 2 subs need to be precisely positioned in the room to optimize the bass response perceived at a single dedicated listening position.
      This specific sub positioning process for 1 or 2 subs restricts good bass response to the immediate vicinity of the dedicated listening seat and, by necessity, results in much poorer bass response at many other areas of the room.  However, some individuals require good bass response at more than just a single listening position and a 4-sub DBA system is an excellent method to achieve good bass response not only at the dedicated listening seat but also throughout the entire room.

rauliruegas: "Normally the owners of planar type speakers are " against " to run the main speakers as a " satellite " one that is the " right " way to go ( for me. ) because that high-pass filter makes a paramount difference."

     I completely agree with you that one of the major benefits of adding subs, and running the main speakers as satellites, is that it frees the main speakers and their amp from reproducing the bass frequencies which results in less speaker distortion and reduces the demands on the amp.
     In my system, I've tried both configurations of running my planar panel mains full-range and with my mains as satellites with their low frequencies filtered out by the sub amp supplied with the Audio Kinesis Debra DBA system,  This amp has a L/R high pass outputs for sending frequencies above the bass crossover setting to the main speakers amps.
     I thought my system sounded best with the main speakers running full-range. The mid-range and treble range sounded very similar to me with both configurations but I did notice the bass range sounded more detailed and more dynamic with my mains running full-range.  
     I do have some thoughts about why I didn't discern improvements in the mid-range/treble range using the 'satellite method' as expected and as you have in your system.  I'm uncertain of the quality level of the high pass filtering being done in the sub amp.  But since I was unable to discern any differences in the midrange/treble response range between full-range and the satellite methods, I can only conclude that the filtering quality level is not an issue.  
     Also, any sonic gains expected from the reduction on bass frequency amplification demands on the main speakers amps may not have been realized since these mono-block amps are not lacking in power ( 1,200 w into the speakers 4 ohm load).  Another possibility is the Magnepan 2.7QR main speakers I use as mains.  These are 3-way planar panels that have rather large bass sections which provide very high quality bass on their own but that lack deep bass impact.  Perhaps the improved bass response I noticed with running the mains full range is a result of the very high quality and articulate bass of my mains combined with the increased impact and dynamics provided by the AK Debra DBA system.
      I think both our systems are just practical proof that there's several options available for achieving high quality bass response using subs.

Tim

Dear @noble100 : """ All DBA systems will provide accurate, detailed, smooth and natural bass that has an effortless quality to it. """

as can do it non DBA subs system.

This statement is false. If you encounter a standing wave, it often cannot be fixed with only 2 subs. And it can't be fixed with room correction or room treatment.

Now if you **don't** encounter a standing wave then its all good. But in many rooms a standing wave is highly likely- unless the room is irregular in some way. But any rectangular room will have a standing wave which will be a different locations throughout the room depending on the frequency. In such cases while that bass might be good at the listening chair for certain pieces of music, it may not for others. This is a simple fact of physics.

With a distributed bass array this problem is solved.

Dear @noble100  : Yes, with two true self powered subs for one seat position. We don't need more for that target. The Harman white papers confirm it.

I think that even that we agree in some bass management subjects the reality is that we can't agree and not because " we can't " as is but because looking your streamlinen system your targets and mines are totally different.

I don't use my system for HT and two channels listening MUSIC. My system was and is developed exclusively for listen two channels MUSIC, nothing more. Music coming from digital and analog alternatives.

As I told you my main target is to stay " nearer/truer " to the recording and to achieve that target I need a very high resolution room/system that means very high quality performance of any single link in the overall audio system chain with true accuracy and the lowest any kind of distortions I can achieve.
Obviously that to achieve all these we have to take care for the minimum details where in HT no body cares and even in two channels system some audiophiles not cares either. 

I gave that little explanation due that you said that using the high-pass filter you was not aware of differences in the quality level performance in the mid/high frequency ranges in your system.
After looking your system I understand now why you been not aware about: your system has not the resolution need it for even that very wide frequency bass range in the Magnepans.

As a fact you are not trying to put all kind of distortions at its minimum you can and that's why you gave me an answer that THD in the quasi-subs you own was not so important when in reality is way important with true self powered subs in a only two channels system. Everything is important and with high priorities in a two channels room/system when we want to stay not so far aways of live MUSIC as normally we are. 
Mi reference to achieve my target is live MUSIC seated at nearfield position ( 2-3m. ) that's where the  recording microphones are positioned.

For me is really important and was one of the reasons I choosed my servo controled Velodyne's that check every second 16K times the woofer excursions to mantain at lower than 0.5%  the THD. Other than Velodyne I don't know other true subs where the manufacturer gives the THD in its products.
I think I already mentioned that the JL very well regarded subs measured through Stereophile review around 6% on THD other subs reknowed subs are worst that that and certainly far away from that Velodyne figure.

I totally understand your fascination for your 4 quasi-subs bass array because for that price is almost imposible to achieve what you like in your system.
The manufacturer design must had to make " serious " compromises to stay at that so low price for the complete bass 4 array.

Anyway, at the end you have what you and me were looking for and if both of us achieved our targets then this is the more important fact.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.