Capital AudioFest 2011

Soundfield Audio

John Atkinson  |  Jul 10, 2011

"Where's the tweeter?" I asked after a listen to the 97dB-sensitive Soundfield speakers, shown at Capital AudioFest in prototype form. It turned out the top drive-unit is a 12" coaxial unit, with the HF unit mounted where the dust-cap would be. "So the big-ass 18" dipole unit is the subwoofer?" No, it was explained, the18" unit in the speaker's center, behind the metal grille, is the woofer, covering the range from 50–200Hz. The bottom 12" unit, mounted in a sealed enclosure is the subwoofer, handling frequencies below 50Hz. With the coaxial and 18" drivers operating as dipoles and the bottom12" unit omnidirectional, by varying the crossover between the low-frequency drivers, the speaker's radiation pattern can be made cardioid in the region where room acoustics might benefit. I had seen a cardioid subwoofer designed by Ken Kantor many years ago at a CES, and had wondered why no-one else had experimented along these lines.

COMMENTS
Kal Rubinson's picture
Submitted by Kal Rubinson on July 10, 2011 - 2:33pm

Is that another, smaller driver on the front panel just above the lower 12" driver or a port to let the upper range of the 18" woofer get to the listener?

John Atkinson's picture
Submitted by John Atkinson on July 11, 2011 - 8:47am

Quote:
Is that another, smaller driver on the front panel just above the lower 12" driver or a port to let the upper range of the 18" woofer get to the listener?

It's a metal-mesh grille allowing the 18" unit to "speak" to the listener through the baffle.

John Atkinson

Editor, Stereophile

terry j's picture
Submitted by terry j on July 10, 2011 - 9:04pm

hi john

guess the novel arrangement was of interest to you (tho surely you have seen coaxials before??)

I know you would not have been able to hear it blind (the best way no?) but anyway, how did it sound?

Is Soundfield Audio a new manufacturer starting out in business? If so, good on you for giving them support and good luck to them. Looking forward to any upcoming measurements.

mdaudioguy's picture
Submitted by mdaudioguy on July 11, 2011 - 8:32pm

I was at the show on Sunday, and unfortunately, did not get to hear these speakers, as they were pushed to the back so that a pair of bookshelves that were in the end-stages of development could be demonstrated. Wow! What a demo it was! I really could not believe that such small speakers could energize a room to the extent that these did (yes, it sounds cliche, but I really, really mean it). My inital thought upon entering the Soundfield room was, "Franken-speakers?? What are these doing here?" I soon got my answer - greatly exceeding expectations!

What I saw was a pair of small bookshelf speakers, each with an 8" JBL (sub)woofer and a KEF coaxial driver. While the KEF was a passive driver, the JBLs were each powered by their own integrated plate amp - which was resting on the floor behind each stand, upon which these speakers were mounted. (The owner assured everyone that production models would have the amp mounted in the cabinet.) He also claimed that low-end response extended into the sub-30Hz realm... and without the benefit of an actual measurement, they definitely seemed to be proving it. Just wow. With handmade crossovers seemingly tuned to perfection, the overall response seemed exceedingly smooth from top to bottom - no doubt a benefit of the coaxial KEFs.

Most interesting of all - all this in a package designed to sell for a mere grand. I don't know how long this DIY-guy-turned-entrepreneur has been at it, but it sure seems as if he's on to something wonderful.

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