Magico introduced the Q series subwoofers

[EspenL]

Hi
Sharing low so there is no problem with using only one QSub, my room is 25kvm to and only one Qsub works excellent.If i had two so it will probably be even better but not twice as good. Do not feel like I'm missing something with using only one Qsub. Having tested many brands but QSub is much better than another brands i have tested in my system. Q sub played clearly more integral and tighter one everything else I had to test.

Espen

 

[microstrip]

(...)

Finally the issue of distributed sub-woofers: Audiophiles are not warm to the notion and that is fine. At least do know that two subs are always better than one and 3 or more even better see the papers I mentioned.

(...)

Many audiophiles prefer two subs because they use them in stereo configuration. Three or more are used in mono. Ask this forum audiophiles (whose systems you referred) that use two subs what they think about a mono subwoofer.

BTW I quote reference 1: (Harman paper on multi subs)

Get lots of output, with flat frequency response at a
single listening seat. With 2-channel stereo systems and
a single listener, it is natural to equalize for flat acoustical
response of the combined subwoofer-room system. In fact,
the interaction of room and loudspeaker is often the
dominant factor in the perceived timbre [1]. This is
especially true at lower frequencies.

Get lots of output, with flat frequency response over a
defined listening area. With multichannel entertainment
systems, there is more than one seat, so the acoustical
response will be different at each seat, and the problem
becomes more complex. Note that multichannel
entertainment systems with large seating areas have been
around for a long time, in the form of cinemas. It is when we
see these systems reproduced in small rooms that low
frequency modes start to become an issue.


With the advent of consumer multichannel systems, there is
a potential for a large number of low frequency devices in a
relatively small room to be operating simultaneously. This
could occur either by running the mains and surround full
range, as some advocate or by having multiple LFE’s. From
an intuitive standpoint, putting a large number of subwoofers
at different locations in a room might seem likely to excite
room modes in a more “balanced” manner, as compared to
a single subwoofer. This idea has particular appeal where
there is not a single listening location, but rather a listening
area.

End of quote

The Earl Gueddes approach (ref 2 and 3) uses 3 or more woofers placed in predefined positions in the room and includes a simple and an user friendly method to setup the system. It even suggests the use of different subwoofers, represents great value for money if you just aim mainly at flat response. I have never read any serious report on its subjective response versus using high quality subs in stereo configuration. As I reported sometime ago, after reading about it in WBF I have bought a DCX 2496 crossover and set a sub system using a pair of large Martin Logan subs, a REL and a large DIY high rigidity sub, in either 3 or 4 subs configuration. Although I achieved excellent measured response at the listening position the subjective bass quality was poor IMHO - it compromised the overall system high performance.

Our other thread in WBF aboutt the Arrakis includes a lot of information and opinions of members relevant to this debate, including an direct report of the opinion of Andy Payor on adding subs to his speakers.http://www.whatsbestforum.com/showthread.php?4411-Arrakis-2&p=290359#post290359

 

[Roysen]

Hi
Sharing low so there is no problem with using only one QSub, my room is 25kvm to and only one Qsub works excellent.If i had two so it will probably be even better but not twice as good. Do not feel like I'm missing something with using only one Qsub. Having tested many brands but QSub is much better than another brands i have tested in my system. Q sub played clearly more integral and tighter one everything else I had to test.

Espen

...but Espen I thought you decided not to crossover very low. I would think you actually would gain a substantial benefit from adding another QSub-15 precisely because you did not follow my advice of crossing over in the 30Hz region (30-40 Hz is what is considered low). I am pretty sure that even though the QSub-15 does not resonate at the crossover frequency you have chosen, you have decided to let the subwoofer play across such a wide frequency area that your room most likely will resonate and reveal the position of your subwoofer.

 

[EspenL]

...but Espen I thought you decided tot to crossover very low. I would think you actually would gain a substantial benefit from adding another QSub-15 precisely because you did not follow my advice of crossing over in the 30Hz region (30-40 Hz is what is considered low). I am pretty sure that even though the QSub-15 does not resonate at the crossover frequency you have chosen, you have decided to let the subwoofer play across such a wide frequency area that your room most likely will resonate and reveal the position of your subwoofer.

Hei Roysen
Det er så enormt mye variabler som spiller inn med tanke på hvor man bør dele en Sub i et rom så å sitte et annet sted uten å kjenne til rommet mitt/frekvensen før justering av Sub osv ...blir synsing. Har man på både lavpass/highpass filter? Hvor bratt justerer man kurven ? Drar man ned peak med bell filterosv... Alt dette + mer....har en stor betydning på hvor man opplever en deling bør være. Hadde 8x12 Tom her i går å han er jo som vi vet litt over snitte interessert i rom å resonanser han var meget overrasket over hvor lite resonanser det var i stua mi Det du bør gjøre først er å lytte/teste/måle en QSub før du konkluderer da den ikke oppleves helt som andre suber (tro meg) Skulle formen din være fin å du har lyst så tar det jo bare litt over 2 timer å kjøre til meg så du må gjerne ta en tur vis det skulle passe for oss en dag.
Nå jeg mente lav deling så tenkte jeg mer på under "stereo" grensa så det er mulighet til å bruke kun 1. ca 80hz så her kom nok min dårlige engelsk å forklaring litt til kort

Espen

 

[Roysen]

Dear Espen,

You are wrong in your assumptions. It is actually quite easy to predict how a single cornerplaced subwoofer will behave in an acousticly untreated room in terms of room resonances and standing waves. This has very little to do with the subwoofer itself and its cabinet stiffness. This is in relation to how the room behaves. I also don't agree that there are countless ways to integrate subwoofers with fullrange speakers. I actually think there is only one theoretically correct way and that is to let the coherency of the main speakers shine through and let them play across its entire bandwith without much overlap to the subwoofer and extend the bandwidth of the complete system by crossing the subwoofers in with very little overlap.

Like the knowledgable people on this forum has tried to tell you and the DIY guys on HFS will never understand it is very different to create a big tower multidriver DIY subwoofer and integrate that with a main speaker not playing fullrange (like 8x12_TOM has done for instance) and to integrate a full range speaker with a subwoofer containing two drivers.

Please don't misunderstand me. I am sure your solution sounds wonderful to you and is the right way to do it for you to acheive what you like. You have to do what you like best for yourself, but the way you and have solved it (influenced by DIY guys not knowing what they are doing I have no doubt) is not the way most successfull integration between fullrange speakers and subwoofers are done. Take a look at what David Wilson has done in his home and read the review of the Audio Physic Rhea by Michael Fremer in Stereophile. My post was a comment to your remark that you crossed over at a low frequency and would not benefit from one more QSub-15. Since you do not cross over at what is considered a low frequency at around 30Hz it is wrong to assume you would not benefit from one additional QSub-15. The reason being that you play the QSub-15 across such a wide frequency area that even though you might not hear the location of the subwoofer directly (with your crossover point I do however think that is highly unlikely), I am quite sure your room will resonate or have standing waves created by the subwoofer which will identify its location. With a lower frequency crossover point and the subwoofer playing across a narrower frequency band the chances for this would have been much smaller. By adding a second subwoofer you would both have been able to cancel out some room artifacts created by the subwoofer you use now and you would have been able to distribute the artifacts the subwoofer is creating across the room and making it much harder to identify its position.

Another big advantage with two subwoofers you are missing out on is that you have a stereo system but you play the lowest frequencies summed up through one transducer. With two subwoofers the deepest bass would also have been played stereo from two transducers like the main speakers.

BTW, You critisize me for telling you my opinion without having heard your room or your system, but isn't the real truth that you are trying to predict how it sounds with two QSubs without ever having tried two subwoofers in your system. I am willing to bet that two QSub-15 will sound much better in your room than the single subwoofer you have now. It has nothing to do with increased output level. You might in fact have to turn the output level down after you have added the second sub.

 

[LL21]

I would really love to hear the QSub...I am imagining that it might just have SUCH low distortion that even at higher frequencies of bass, its clean and fast...and matched to a Magico speaker, it might just seem invisible at a higher crossover than 'typical' for full range speakers.

I admit of course that with Wilson, the bigger Wilsons are crossed over at 35hz+/- as specified by Wilson with their own equipment doing all the work. So I too have found that sub 40hz crossover works best for my own setup. And it has taken many years of adjusting my ears to continue to hone/find 'added distortion'/hone some more/'find more added distortion'...to get to the point where I am today, where I now feel like can pick up distortions within my system which I am working one at a time to isolate and then reduce over time.

One of those distortions was (many, many years ago with my Strads) coming from setting the Velodyne too high. Of course, I suspect my wonderful Velodyne is not up to the comparison with a QSub, and thus why I do ask if the QSub's distortion at higher bass (80hz) is so low that it truly matches the accompanying Magico speakers and thus creates no 'bleed/bloat'.

 

[EspenL]

Hi
When I tried to integrate Burmester Sub I had to go too at least 30-40HZ lest Suben would take too much of, but with Q sub to Q3 speakers was this completely different for my ears (believe me)

Espen

 

[EspenL]

Dear Espen,

You are wrong in your assumptions. It is actually quite easy to predict how a single cornerplaced subwoofer will behave in an acousticly untreated room in terms of room resonances and standing waves. This has very little to do with the subwoofer itself and its cabinet stiffness. This is in relation to how the room behaves. I also don't agree that there are countless ways to integrate subwoofers with fullrange speakers. I actually think there is only one theoretically correct way and that is to let the coherency of the main speakers shine through and let them play across its entire bandwith without much overlap to the subwoofer and extend the bandwidth of the complete system by crossing the subwoofers in with very little overlap.

Like the knowledgable people on this forum has tried to tell you and the DIY guys on HFS will never understand it is very different to create a big tower multidriver DIY subwoofer and integrate that with a main speaker not playing fullrange (like 8x12_TOM has done for instance) and to integrate a full range speaker with a subwoofer containing two drivers.

Please don't misunderstand me. I am sure your solution sounds wonderful to you and is the right way to do it for you to acheive what you like. You have to do what you like best for yourself, but the way you and have solved it (influenced by DIY guys not knowing what they are doing I have no doubt) is not the way most successfull integration between fullrange speakers and subwoofers are done. Take a look at what David Wilson has done in his home and read the review of the Audio Physic Rhea by Michael Fremer in Stereophile. My post was a comment to your remark that you crossed over at a low frequency and would not benefit from one more QSub-15. Since you do not cross over at what is considered a low frequency at around 30Hz it is wrong to assume you would not benefit from one additional QSub-15. The reason being that you play the QSub-15 across such a wide frequency area that even though you might not hear the location of the subwoofer directly (with your crossover point I do however think that is highly unlikely), I am quite sure your room will resonate or have standing waves created by the subwoofer which will identify its location. With a lower frequency crossover point and the subwoofer playing across a narrower frequency band the chances for this would have been much smaller. By adding a second subwoofer you would both have been able to cancel out some room artifacts created by the subwoofer you use now and you would have been able to distribute the artifacts the subwoofer is creating across the room and making it much harder to identify its position.

Another big advantage with two subwoofers you are missing out on is that you have a stereo system but you play the lowest frequencies summed up through one transducer. With two subwoofers the deepest bass would also have been played stereo from two transducers like the main speakers.

BTW, You critisize me for telling you my opinion without having heard your room or your system, but isn't the real truth that you are trying to predict how it sounds with two QSubs without ever having tried two subwoofers in your system. I am willing to bet that two QSub-15 will sound much better in your room than the single subwoofer you have now. It has nothing to do with increased output level. You might in fact have to turn the output level down after you have added the second sub.

Hei Roysen
Er noen ting her jeg ikke er enig med deg i å noe jeg er svært enig i. Da jeg ikke er så sterk i Engelsk så kan ting misforståes veldig fort vis jeg ikke greier å forklare meg bra nok så jeg velger å ikke fortsette diskusjonen på det grunnlaget, men ta gjerne opp disse tingene med meg når jeg kommer hjem til deg så kan vi ta en prat rundt disse tingene.
Espen

 

[EspenL]

I would really love to hear the QSub...I am imagining that it might just have SUCH low distortion that even at higher frequencies of bass, its clean and fast...and matched to a Magico speaker, it might just seem invisible at a higher crossover than 'typical' for full range speakers.



Hi

I really agree with you here writing LL21

Espen

 

[LL21]

I would really love to hear the QSub...I am imagining that it might just have SUCH low distortion that even at higher frequencies of bass, its clean and fast...and matched to a Magico speaker, it might just seem invisible at a higher crossover than 'typical' for full range speakers.

Hi

I really agree with you here writing LL21

Espen

Most interesting!!! I really need to hear the QSub...I am trying to imagine what happens if I go from very good sub-40hz bass to exceptionally low distortion bass perhaps like QSub...even if I leave QSub at a crossover at or below 40hz...

 

[microstrip]

(...)

Another big advantage with two subwoofers you are missing out on is that you have a stereo system but you play the lowest frequencies summed up through one transducer. With two subwoofers the deepest bass would also have been played stereo from two transducers like the main speakers.
(...)

Yes. There was even a paper presented at the last AES convention on this subject. Although I do not have free access to it and can not comment on it, I list the abstract.

P9-3 Subwoofers in Rooms: Stereophonic Reproduction—Juha Backman, Microsoft - Espoo, Finland
A study based on computational model of interaural level and time differences at the lowest audio frequencies, often reproduced through subwoofers, is presented. This work studies whether interaural differences can exist, and if they do, what kind of relationship there is between the loudspeaker direction and the interaural differences when monophonic and stereophonic subwoofer arrangements are considered. The calculations are made for both simple amplitude panned signals and for simulated microphone signals. The results indicate that strong narrow-band differences can exist, especially near room eigenfrequencies when the listener is close to nodes of the room modes and that the modes of the recording room can have an effect on the sound field of the listening room.

 

[TDX]

Now I see the Titan is coming, even bigger and better?