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Subwoofers and Phase Question For You Sub Experts

I use a pair of Dunlavy SC-3 speakers, known for their time/phase coherent crossover design.

When the stars align the speakers completely disappear and there’s a sense of space and 3 dimensionality that I’ve heard from few other speakers/systems. It’s easy to destroy the illusion with things like poor placement, poor setup of room treatments, etc.

Adding subs to the setup is both a blessing and a curse. The Dunlavy’s need some support in the nether regions and a pair of HSU subs do add a solid foundation to music which enhances the overall presentation; however, it’s at the expense of some stage depth, width and image dimensionality. Placing the subs a few inches forward of the front plane of the speakers helps a little but that isn’t where they perform at their best as ‘subwoofers’.
Finding optimal room positions for bass augmentation always creates a clash with the phase aspect of integration resulting in the diminished soundstage described above.
Playing with phase settings has little impact on the problem since there’s just a toggle for 0 and 180.

Which brings me to the questions - 
1/ How does running a swarm setup, with 4 subs, affect phase/time integration with the mains? Does it create twice or half the issue or remove it altogether?

2/ Looking at subs such as the JL Audio F series with auto room calibration, does the EQ algorithm compensate for any time/phase anomaly or is it simply looking for a more linear bass response?

I don’t mind investing in more sophisticated subs so long as I don’t end up with the same problem. I’m not really inclined to mess with software and the like, unless there’s no other way.

Thanks

Rooze


128x128rooze
mijostyn's avatar
mijostyn
8,570 posts
 
Rooze, it is a complex issue. Properly set up subs should improve sound stage and clarity. Speakers that benefit most from subs have woofers that run up higher above 500 Hz. Full range speakers like ESLs benefit most.
Ideally the sound from the sub should reach the listening position at exactly the same time and at exactly the same phase angle as the woofers in the satellite speakers. Subs work best against a wall and better right in corners. This is usually not going to be time or phase correct. Some woofers like the JL Audio have adjustable phase angle which helps but this does not correct the time issue. In most cases you would have to delay the satellite approximately 0.3 milliseconds each millisecond being equivalent to about 1 foot. This can only be done digitally. So in order to put subs in the places they work best and integrate them to the satellites you have to have digital bass management. If all your sources are digital this is not difficult. A dBx DriveRack will do the job. Digital room control processors like TACT, Anthem and Trinnov units will do the job for you. If you are into analog only and unwilling to digitize your turntable it is probably best to avoid the subwoofer altogether. Doing a swarm system would be the best way to go with an analog system. 

kenjit
1,771 posts
 
Ideally the sound from the sub should reach the listening position at exactly the same time and at exactly the same phase angle as the woofers in the satellite speakers.
Which is not possible with the duke le june swarm technology 
audiokinesis
2,753 posts
 
Noble100 wrote: "This knowledge was the impetus for Duke creating his 4-sub Swarm DBA system that has won multiple product of the year awards (2015 and 2019):"

Just to clarify, the Swarm only received a single Product of the Year award, for 2015, from The Absolute Sound magazine.  It has also received three Golden Ear awards and three Editor's Choice awards, including one of each in 2019.  So apparently the concept has a decent shelf life. 

And as I have said before, my product is definitely not the only way that the distributed multisub concept can be employed.  And results can be further improved with EQ and bass trapping.  Nor is a distributed multisub system  necessarily the most practical solution for most people... if it were, I'd be sitting in my corner office smoking a cigar while my minions did all the work. 

Duke
audiokinesis
2,753 posts
 
@kenjit quoting millercarbon and then replying:
"
ideally the sound from the sub should reach the listening position at exactly the same time and at exactly the same phase angle as the woofers in the satellite speakers.
"Which is not possible with the duke le june swarm technology"

Of course it’s possible, if arrival time synchronization is your priority when you set the system up. It is not my priority because other things matter much more.

The ear does not BEGIN to have enough time domain resolution in the bass region for small differences in subwoofer arrival times to matter. The ear DOES have PLENTY of resolution in the loudness domain, so frequency response smoothness (which correlates precisely with good decay characteristics) matters a LOT.

Duke
audiozenology
362 posts
 
Ideally the sub should be crossing over from the mains at a frequency where localization isn’t possible rendering time alignment not critical. If you force time alignment, then you force maximum wave reinforcement in the listening position which negates the point of a distributed bass array to even out frequency response by negating room modes.


Ideally the sound from the sub should reach the listening position at exactly the same time and at exactly the same phase angle as the woofers in the satellite speakers.

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