Interesting video, thank you.Hearing instead of reading the facts and theory was really helpful.
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At 80Hz the waveform is 14 feet long.
The ear cannot know the sound is there until the entire waveform has gone past it.
It cannot sort out the frequency until 2-3 more iterations. By this time the waveform has bounced off of the rear wall (unless you have an enormous room!) and is making its way back- and has probably already passed the listening chair by the time you can even tell what the bass note is.
So in most rooms anything below 80Hz is entirely reverberant. So its not directional at all at 80 Hz, let alone 50Hz.
The other takeaway: if you have a room with the wall in front being roughly parallel with the wall behind you, there will be standing waves no ifs ands or buts. This is why there can be good bass everywhere in the room but the listening position, and this cannot be treated with room treatment or room correction.
If a standing wave is cancelling bass at the listening position, you could put 10,000 watts worth of correction at that frequency and it would still cancel.
This is why multiple subs (Distributed Bass Array) works. If properly placed (asymmetrically in the room) they will break up standing waves, resulting in evenly distributed bass throughout the room.
Audiokinesis http://www.audiokinesis.com makes a subwoofer system called the Swarm that is 4 subs meant for this purpose. Unlike most subs, they are designed to sit directly against the wall, taking advantage of the room boundary effect. This allows them to be more compact and easier to place, especially if space is limited. I have Swarm subs in my system- they work a treat!
The trick is to keep their output below 80Hz so they don’t attract attention to themselves. Stupidly easy to set up too.
How many times do we hear this one?
((((They need a VERY large room. Most homes don’t have the kind of space they need. They sounded best out a good ten feet from the back and side walls.))))
One of the best solutions we have found is a pair of Vandersteen Sub3s
They offer a unique solution for every room with its non DSP adjustable analog tuning from 22 hz to 130hz on each channel. One of the Martin Logan dealers at the time ran a pair of Vandersteen High Pass filters and Vandersteen Subs achiving fantastic results and got best sound at show with CLS. We have also sucsessfully paired many pairs of Vandersteen subs with Magnepans and other planar speakers
Taking full advantage of their unique High Pass/ bi amping allows lower distortion in the main panels or any speakers, dramatically improving the clarity and transparency of the whole system, while tuning out unwanted heavy bass that overloads most all rooms. This for me has always been the best solution. .
@danager Early in his vid Mr Geddes says damping all the room boundaries is good for bass. Then just after 17m he says it won't do any good at all. Kinda put me off him, that and his whiny voice and condescension, including to members of his audience.
@avanti1960 Methinks you protest too much about REL. They are good subs and already on my shortlist. Do you represent them at all?
@atmasphere The Swarm looks interesting in principle and good value. Putting in 4 subs to cancel room reverberation is a bit like herd immunity. I suppose 'herd' = 'swarm'.
But why are they two feet tall? What's the other half of the cabinet doing? They're not really 'compact' at 23x12x12 inches. Why do we have to have old-fashioned wood veneer finishes? Why don't they quote the frequency range between dB limits? And, as @tomic says, any small sub can be 'swarmed'.
@atmasphere The 14 foot wave takes 12 milliseconds to pass my ear. Is that fast or slow? My MLs are flat at 80Hz and the bass there is pretty tight, not an unrecognisable reverberating mush. What's more I can hear it arriving from its source on the soundstage. I await to hear how much worse it gets at 25Hz. And whether it's really true my room boundary damping won't make any difference.
@audioconnection What is it about the design of the Vandersteens that allow them to behave so differently as a stereo pair with essentially the same control systems?
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