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Why is good, deep bass so difficult? - Myths and their Busters

This is a theme that goes round and round and round on Audiogon. While looking for good sources, I found a consultancy (Acoustic Frontiers) offering a book and links:

http://www.acousticfrontiers.com/guide-to-bass-optimization/?utm_source=CTA

Interestingly: AF is in Fairfax, CA, home to Fritz Speakers. I really have to go visit Fairfax!

And a link to two great articles over at sound and vision:

https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-1
https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-2

Every audiophile who is dissatisfied with the bass in their room should read these free resources.

Let me state unequivocally, deep bass is difficult for the average consumer. Most audiophiles are better off with bass limited speakers, or satellite/subwoofer systems. The former limits the danger you can get into. The latter has the most chance of success IF PROPERLY IMPLEMENTED.

The idea that large drivers/subs are slow is a complete and utter myth. Same for bass reflex. The issue is not the speed of the drivers. The issue is usually that the deeper a speaker goes the more it excites room modes, which the audiophile is then loathe to address.

Anyway, please read away. I look forward to reading comments.
erik_squires
willemj
1,036 posts
 
Duke,
Your Swarm system is indeed interesting and sounds like the theoretically correct solution, even if one with rather a lot of boxes in the room. In my case, I think I will continue to save for a second PV1d, used with the Antimode, as a domestically acceptable compromise (the big stats have already been pushing the boundaries). Did you ever compare (and measure) your Swarm used with room equalization?
audiokinesis
2,737 posts
 

Thank you, willemj. 

The amp I supply with the Swarm has a single band of parametric EQ, but most people don't use it.  The only time I've used it has been to extend the very bottom end a bit when all of the modules were in sealed-box mode,  in a situation where we really should have left some of the ports unplugged but the customer insisted they all be plugged.  We used a real-time analyzer but didn't save any of the curves.  I haven't heard from anyone who has made measurements with the parametric EQ in play.  I have heard from multiple customers reporting +/- 3 dB in-room across the bass region, with the -3 dB point clocking in a bit south of 20 Hz, without EQ.  

One of my customers had been using a Meridian processor that had been professionally calibrated for his previous sub.   He reset all the filters to flat and called in the technician after he had set up the Swarm.  After making his measurements, the only thing the technician did was adjust the level a bit.  No further equalization was needed.  Apparently the technician said he'd never seen anything like it, and he'd been doing this for many years.   

But it's not either/or!   I am sure the Swarm would work very well with EQ, especially something well thought-out like the Antimode, in part because the spatial variation (change in frequency response at different locations) is greatly reduced by the distributed multisub configuration. 

Duke

soundsrealaudio's avatar
soundsrealaudio
756 posts
 
wolf_garcia

The show is pretty easy in easy out. Frontier Airlines " cheap flights now on sale " to DIA then $35 shuttle to Marriott. There are other hotels close by that are cheap to stay at. 

I am going to be in the Bricasti Room 7013. Managed to get a pair of Wilson Benesch Evolutions to take to the show. Should sound great, I have a good history at the show. In another room, the Larkspur Wilson Beseech will have a pair of the Torus Infrasonic Generators. Or as Jonathan Valin said " 

"Strokes of genius are rare in any field,
          but I think Milnes’ Torus qualifies”

 - Jonathan Valin, The Absolute Sound, 2007

Anyway if you make it you can try to be kind to me, even if you have to go  against your nature.


willemj
1,036 posts
 
Hence the need for a low output impedance (which is a different way of saying the same). If the damping factor is too low, the frequency response becomes heavily load dependent, with potentially exaggerated bass or high frequency roll off (or other anomalies). Typically, this is not a problem with the better solid state amplifiers, but it is with tubes. Perhaps that is why some audiophiles like them.
EDIT: sorry this was a response to an earlier post about the need for a high damping factor.
willemj
1,036 posts
 
Duke,
Thanks for coming back to me. That sounds like a nice flat response, but it is of course room specific, and not always achievable. You are right that since multiple subs give a flatter response over a far larger area, the potential for equalization is even greater. So I guess the right answer is to get the basics right by using more than one sub, and not shy away from some smart equalization either, particularly now that units like the Antimode 8033 are so easy to set up, and so cheap.
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