Subwoofers are a superlative room treatment


Several months ago I posted about how KT 170 tubes improved my overall sound and in particular improved the boomy bass I was experiencing with KT 150 tubes.  During the discussion @Mijostyn suggested that my Swarm subwoofer system was likely inadequate for my S7 Magico speakers which each have 3 10" woofers and adding more subs would make a big improvement in my sound.    The swarm has 4 10" passive speaker cones.  @Mulveling opined that I likely had more than enough bass with the S7s alone.  I had spoken with Mike at Suncoast Audio who also brought up adding more subs to the system.  My low end was much better with the new tubes and it seemed counterintuitive to add more subs to tame the sound, but Mike has never been wrong regarding my system.  So I took the plunge.  He recommended 4 B&W DB1B subs with 2 active 12" drivers with DSP.  I bought two and he let me test drive an additional two.  These subs are staggered in the room, similar to a Geddes set up, but none are behind the listening position.  I wasn't really sure how my sound would end up and was actually a little nervous that the bass would overwhelm the overall sonic presentation.  My fears were unfounded.  The bass was definitely better than before-more focused and rich.  But the big surprise was that the overall sound was vastly improved.  The sound stage expanded with more air between instruments.  The tone improved as well.  My wife (with hearing aids) and daughter who are very familiar with the system each said the same thing within 10 seconds of listening.  "It sounds so clear".  This "upgrade" has had by far the largest impact on sound in my system-more so than upgrading to the VAC Master Preamp.  So reflecting on why it is so much better than my previous sub array- its clear there must be a ratio of subwoofer square area and woofer square area that is optimum.  Or the DSP aspect set to the listening spot for each sub, or a combo of the two.  @mijostyn had alluded to the ratio in my last post as being important.  The set up is straight forward and there is no connection with the speaker crossovers.  The crossover on the subs was set to 70.  I post this so others may be encouraged to consider a similar approach.  These subs improved the low end, but the most impressive aspect is that they act like a whole room sonic filter of the highest order-without altering the sound from the mains.  Incredible. My room has had acoustic treatments consisting of corner bass traps with diffusion, first reflective point dispersion/absorption, quadratic diffusers, ceiling absorption and HFT's that have been in place for years.  The subs are king of them all. 

orthomead

This is the Analog Forum which usually means vinyl but we all listen in the analog domain. Please clarify, are the S7s attenuated by a high pass filter at or near 70 Hz?

Thanks for posting, I've never heard a swarm, you explain yours well.

Tell me you live nearby, and I’m invited! I’m in Plainfield, NJ 07062. Oh, Suncoast Audio, Sarasota, FL, hmmm, I just bought a car in Tampa, flew down, took a week coming home, could have taken you for a ride in my Twin Turbo V8 with the B&O upgraded sound system and heard your system.

Actually, the best thing would be to have heard it both before and after, sounds like you know how to take good advice, congrats.

The S7s are not attenuated and untouched.  I purposely placed this post here because I only listen to vinyl and the overwhelming majority of great tips I have received have been on this forum.  

I ask because I’ve been debating the expense and complexity of adding subs to my Sound Lab ESLs. As I’m sure you know, it’s technically easier on the main amplifier if you high pass. But it’s simpler and less potentially harmful to phase response if you don’t, and you didn’t.

If your amps are currently taxed with your speakers, you may wish to high pass.  I have found that I'm going from 12 o'clock on the Pre amp to 2ish now.  This is about 92dB.  I asked Mike at Suncoast about that since nothing should affect the mains, and he said that with the noise removed, he also tended to turn up a little more because it just sounds great. Perhaps @mijostyn will chime in regarding the requirements for your system.  

@orthomead 

Enjoy the great sounds!

You mentioned DSP, so I assume you did some calibration process to allow it to optimize its settings?  Are only the 4 subwoofers under DSP control?

@orthomead

No offence intended, but your fairly long OP would have been much easier to read and understand, if you’d broken it up into meaningful paragraphs. You’ve made it hard for the reader to follow your arguments.

congrats you are happy ! are the new subs servo controlled subs ? and what size are they ?
i think there are a # of YT videos extolling the value of multiple subs and i think it is a no brainer now proven they work
are those vented or sealed ? some advocate using bOTH!
I am going to try open baffle servo subs 12 "
some chaps elsewhere were debating "fast bass:" which ( to me just means it is controlled better like w/ servo subs and i am quite sure the servo subs are MUCH better than they used to be) older ones had reliability issues

funny why is it all the old guys think speaker tech just STOPPED! like 20 years ago and new speakers and subs are not better ? ? are they just lazy to keep up ? so just dismissive ?
reminds me of some of the old profs at university who just were resting on their laurels and had not done any noteworthy research in years ! we always wondered if their brains had atrophied ?
when i watch the good , honest reviewers on YT like new record day , audioholics etc they sure seem to be saying the newer are better and say so! even prove it w/ measurements ! ( and YES they are LISTENING too! -love it when some curmudgeon intones whining "but do they LISTEN " to them LOL 

Although well down scale from your system, I added two Rythmik F12 Subs to my Fyne Audio F-702s--driven by a Rogue RP-7 preamp and Odyssey Kismet monoblocs, and the improvement in sound quality seems to extend far beyond the lower bass realm.  Similar to your experience, the tonal quality, sound stage, and imaging all seemed to improve by a significant margin.  Even my wife, who is not as "into" audio as much as I am immediately noticed a significant difference.  No swarm of subs for us, however, as our room is not large enough.  We ae quite pleased with the realism we are achieving with the system.

I'm Jealous, but happy for you. I'm running B&W 702 S2's with a pair of B&W DB4s subs. Yours are their flagship with the  dual 12" drivers and 2,000w to drive them. I was thinking of getting one of your DB1D's instead of the dual DB4s's, but liked the ability to pair one with each channel/monoblock. Don't get me wrong, the DB4s is really nice, I might move to 4 of them if it's worth it. Right now focused on building a new room for the system.

Quickjack, you’re not so quick. The OP clearly states what woofers he’s now using. From that information you can answer all your own questions. And, apart from the rise of open baffle designs and a few other ideas, I’d say there really is not much that is really new under the subwoofer sun. The Swarm has been around for at least 25 years, for example. Plate amps are better, for sure.

I recently added a six pack of REL Carbon Specials to my Rockport Cygnus. I was very nervous to add that much expense to my system, but what a reward. I intend to do a second "tune" but they already add so much to my listening experience that I have stopped yearning for MORE. I just love listening to the system as it's so engaging!

Dear @wokeuptobose ​​@orthomead  and friends:

https://www.harman.com/documents/multsubs_0.pdf

 

""  For practical number of subwoofers, there appears to be no obvious there appears to be no obvious correlation. There is certainly no correlation. There is certainly no justification for using more than four. justification for using more than four. """

 

""  Four subwoofers are enough to get the best results of any configuration the best results of any configuration tried.  Two subwoofers is very nearly as good and has very good low as good and has very good low frequency support as well. frequency support as well. ""

 

Choosing the " rigth " subwoofers is critical to use 2-4 subs. Normally 2are

enough if we are using ahigh pass filter for the main speakers.

Both of you own great speakers that go down to 20hz, good.

 

Harman research is know for to many years to remember and Harman own ( between others ) B&W, Infinity, Levinson, etc. etc.

 

So, follow enjoying MUSIC aand congratulations,

 

R.

Thanks to all for the feedback!

@petaluman The subs interface with an iphone app which is pretty easy to use. Each sub is independently calibrated to the listening position. The only DSP in my system is with the subs.

@newton_john Sorry for the ramble, mate.  

@quickjack1234 They are sealed non servo subs with 2 12" aerofoil cone drivers.

@mike4597 I'm happy to hear that you have also noticed the non bass benefits of multiple subs.  I keep going through my old discs listening to songs I thought I knew well.   My room is fairly large so 4 is the right number, but I'm not sure there is a massive difference in going from 2-4 in a smaller environment.  Also, I'm convinced that there is an ideal woofer to subwoofer ratio. 

@katzenjammer27  I like the idea of getting the room right.  When we bought our house, I removed some walls and changed the ceiling height to get as close to the golden ratio as possible. Then built the system around the room.   With a good room set up, the subs will do more I think.

@wokeuptobose Congratulations on getting your system where you love it!

@rauliruegas Thanks for the great link.  Very interesting!

@orthomead 

Thanks for the additional details!  FWIW, DSP and servo control both correct the input to improve the output fidelity.  The DSP also does its calibrated frequency response shaping across the swarm.  The servo mechanism may be more accurate if the voice coils heat up, which seems less likely with 5 woofers in play.

lewm
typical cheap shot ad homenin comment grow up school yard bully how about you just scroll on i was not asking you !

typical, you deny progress which proves you have not kept up exactly my point !
he answered my ? BTW thx!
"@quickjack1234 They are sealed non-servo subs with 2 12" aerofoil cone drivers." so arguably NOT state of art , could be better why i asked