I'm pretty much in a nearfield position about 8 feet from my loudspeakers based on Cardas for a rectangular room. My room is about 12' x 15'.

http://www.cardas.com/pdf/roomsetup.pdf

About 10'. Big listening room (about 30'x35', 32' ceiling).

Dunlavy SC-IVa's

I'm 12' - 14' from the speakers. Room: 14x25x9

Cardas postulates an interesting definition of "near field"; when the listening position is at one corner of an equilateral triangle.

I have always thought of near filed as a listening position close to the speakers which minimizes room interaction, perhaps a meter or so away, such as when listening to studio monitors for mixing.

I was just chatting about this with my neighbor during a listening session over the weekend.

I think I tend toward farther field, in general.

Of the places I listen:

1) Planar speakers about six feet from back wall and six or more feet from any given side wall, with outer edges of speakers about 12 feet apart...I listen at about 15 feet.

2) Planar speakers, different room, about 12 feet apart...around 12-15 feet away for listening.

3) Single driver horn speakers, with open baffle, so only about one foot from rear wall, about 10 feet apart...I listen at about 15 feet, or even more, sometimes 20 feet away.

4) Computer system - nearfield listening. About 2-3 feet from speakers.

My room is 14' by 10' and I sit 8' away from my speaker which are about 5' into the room measured from the front baffle.

I sit 7' away from the plane of the (single driver) speakers with a bit over 9' between speakers. So a shallow triangle. But how far you might want to sit from any particular speaker will depend on the speaker. Time aligned speakers tend to require a certain distance for the drivers to coalesce into a properly integrated combined soundfield. There is a "just right" spot that is neither too far away nor too close. Various types of crossover networks will have a lobing affect on the multiple drivers' integration and will require a correct distance from the plane of the speakers. If you sit too far away or too close to any of these designs, there will be a hole in the speaker sound or an obvious misalignement of the drivers characterized by a suck out in the frequency response. Listening in the near field to horn loaded drivers in a multiple driver system is excruciatingly wrong.

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Time aligned speakers tend to require a certain distance for the drivers to coalesce into a properly integrated combined soundfield.

I agree. This is very true for both my Dunlavys and Dahlquist DQ-10's - both of which are time and phase aligned (a sound I really like).

Inherent time and phase alignment is another reason to seriously consider single full-range drivers.

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Time aligned speakers tend to require a certain distance for the drivers to coalesce into a properly integrated combined soundfield.

I agree. This is very true for both my Dunlavys and Dahlquist DQ-10's - both of which are time and phase aligned (a sound I really like).

Inherent time and phase alignment is another reason to seriously consider single full-range drivers.

I agree.

I have found myself particularly fond of single driver (planar/Lowther) drivers.

Time alignment, and maybe all the stuff I've learned about crossovers lately, may all come into play.

As someone that tests radar antenna as part of my job, I am familiar with the concept of near field, Evanescent, reactive regions and far field Fraunhofer regions. These differences between near and far field have to do with wavelengths and electrical vs. magnetic modes.
What is the meaning of nearfield and farfield when used in adio?

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What is the meaning of nearfield and farfield when used in adio?

Near field is the region where the inverse square law does not apply. Beyond near field (far field), the level will decrease by about 6dB for every doubling of distance. Certainly a lot simpler than the definitions you deal with.

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What is the meaning of nearfield and farfield when used in adio?

Near field is the region where the inverse square law does not apply. Beyond near field (far field), the level will decrease by about 6dB for every doubling of distance. Certainly a lot simpler than the definitions you deal with.

Thanks for the reply. Got me to get out my Master Handbook of Acoustics reference to check out your reply. From my checking, I think that your 6db inverse square rule only applies to an unenclosed listening area.
The definition of moving several loudspeaker dimensions away are far field cause me to ask " what are loudspeaker dimensions"?
And actually in my antenna testing all that I have to do is make sure that I probe the test antenna at a distance from the reactive region generally by using a distance of greater than 5X the wavelength.

Great question, cyclebrain! We tend to through these terms around freely, without defining them.

I think of near field as purely a function of listening distance from the speakers. It is close enough that one can hear essentially everything that comes out the speaker. In a sense, this comports with CharlyD's response.

As a practical matter, to me this means one meter or less between the listener and the drivers.

My definition is somewhat akin to the proper definition of point blank range in ballistics: the range of distances at which the projectile will strike the target without the need to change the elevation of the gun.

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Time aligned speakers tend to require a certain distance for the drivers to coalesce into a properly integrated combined soundfield.

I would think that time aligned would be correct at any distance. Aligned is aligned. A speaker that is not properly time aligned would have peaks and nulls of alignment at various distances and frequencies. At least that's what I think.

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I would think that time aligned would be correct at any distance. Aligned is aligned. A speaker that is not properly time aligned would have peaks and nulls of alignment at various distances and frequencies.

It would depend upon how the speaker system were made "time aligned". In a single driver or co-axial system there is a generally considered "time alignment" no matter where you are in distance from the driver's center axis. This is established by the acoustic center of the driver being the originating point for all signals from the driver.

Once you begin to discuss multiple driver systems being "time aligned" you must know more about how the alignment was achieved. Time aligned is not necessarily phase aligned which is not necessarily phase coherent. Sloping a front baffle does not phase align the drivers. Adjusting phase in the crossover can make the system phase aligned but not time aligned. Reversing polarity to a driver will not make the system time aligned but should make the two drivers transient accurate.

http://www.thielaudio.com/THIEL_Site05/Pages/FAQs/faqtimephase.html

http://www.geocities.com/kreskovs/TimeAligned1.html

By my recollection, any multi-driver system that employs a sloped front baffle will require a certain amount of distance away from the acoustic center of the system to complete the time alignment. Such a system will also be back out of alignment after another similar distance is reached.

Again, I would think that time/phase alignment would be the same thing if done properly and independent of listening distance. I can understand that simply time aligning a speakers drivers would not provide phase alignment because of its reactive (phase vs. frequency) crossover. Still I believe that in an ideal speaker time alignment and phase alignment will be the same and will be the same at all distances.

I guess you'll have to define "ideal" loudspeaker.

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I guess you'll have to define "ideal" loudspeaker.

Bose of course

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Again, I would think that time/phase alignment would be the same thing if done properly and independent of listening distance.

This is just a guess, but in multi-driver designs it may be a function of the distance between the drivers.

I do know however that multi-driver speakers which are phase and time aligned need to be listened to from some distance. Big speakers such as Dunlavy's need a good 8-10 feet before they are totally coherent.