Nearfield sub response

[454Casull]

Markus Mehlau posted an article on his site showing that the response at the listening position was extremely good for subs placed close to the listening position.

Comparison of different near field and far field subwoofer configurations

dantheman was not able to reproduce his results.

audio blog: Dry (fast) Bass...

Does anybody have an idea of what's happening here?

[weltersys]

Different rooms, different subs in different locations, different test systems = different results.

[454Casull]

So there is no causation in nearfield subs = smoother response?

[sreten]

Hi,

Near or far field has no real effect on interaction with room modes.

The shape of the room, the listening position and placement of
the subs affects the perceived response, its probably fair to
say there is no such thing as nearfield and farfield for subs.

rgds, sreten.

[head_unit]

"Nearfield" has a very specific definition from (IIRC) JBL's Mark Gander, a quite nice guy who wrote the paper describing the concept.

"Nearfield" means you are so close to the subwoofer that the environment is not affecting the sound pressure.* As a corollary, if you moved a measurement microphone back and forth a tiny amount, the sound pressure would not change. It means you are almost touching the woofer cone.

Bill Basore at Q-Logic once did a demo at CES where they had a subwoofer right smack behind a car seat. You didn't hear much in the room, but sitting in the seat you had firm smooth bass.

So if you could put the subwoofer next to your head, you could get amazing results. Once your ears get some little distance away, you're not in the near field, and "your mileage may vary."


*Well, the environment's loading can affect the raw response of the woofer. But "near field" implies the sound has not had any chance to spread out, so neither room modes nor dispersion are not changing the raw SPL the woofer emits.

[markus76]

Originally Posted by 454Casull

Does anybody have an idea of what's happening here?

Dan's subs were too far away (1m). Please see http://www.geddes-audio.com/forum/sh...ld-results-but...

[markus76]

Originally Posted by sreten

Hi,

Near or far field has no real effect on interaction with room modes.

The shape of the room, the listening position and placement of
the subs affects the perceived response, its probably fair to
say there is no such thing as nearfield and farfield for subs.

rgds, sreten.

Get out your measuring gear. You'll find that in the near field there's virtually no room interaction.

[markus76]

Originally Posted by head_unit

"Nearfield" has a very specific definition from (IIRC) JBL's Mark Gander, a quite nice guy who wrote the paper describing the concept.

I wasn't aware such a paper exists. Do you have more information about it?