I discuss what I call "LSESL", or Line Source ESL design, in my most recent article at Dagogo.com. I'm referring in that term to the Kingsound King, a large planar (You can tell I'm just a BIT excited about this technology). Quad has used a similar concept in their speakers for years, and we all know how that's been received. To my ear, the multi-driver concept with the ESL technology is a fantastic combo. One can certainly achieve a tremendously satisfying result implementing multiple ESL drivers as opposed to cones.
Why so few high end line arrays?
To me the intrinsic "wall of sound" of this design are compelling. I recently tried a very nice 3 way w/ stereo subs in my system after 2 years of line array-only listening and the lost impact and scale of eight midbasses/ribbons per side was profound. I was immediately aware of the music emerging from boxes, despite very nice imaging. And it's not that the arrays exaggerate the size of voices and instruments. Does the materials cost dissuade manufacturers? Is it the size? Seems like relatively unexplored territory in high end home audio.
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09-04-09: ShadorneNot entirely true. Comb filtering is NOT an issue in nearfield listening if the center-to-center distance of the drivers used does not exceed a distance equal to the speed of sound (at ocean level) divided by the highest frequency handled by that particular line of drivers (bass, mid-bass, treble). Dr. James R. Griffin, Ph.D, has a fairly definitive white paper on the subject titled "Design Guidelines for Practical Near Field Line Arrays"(.pdf) that discusses the subject in-depth. In the paper, he provides all the basic criterion for creating a successful line array: Center-to-center Driver Separation (Circular drivers). We want our discrete driver array to approximate a continuous line source. This spacing is the separation between the centers of the adjacent drivers in the line and includes any mounting allowances and the flanges surrounding the drivers. In the limit the closest spacing would be dictated by the flange diameters of the drivers although some drivers have truncated flanges that would allow closer spacing. Two different solutions (Table I) for the driver separation guidelines are presented in the literature for circular drivers. These cases are: |
Darkmoebius, For the sake of brevity I did not go into as much detail. Yes it is true that a line array of woofers operating below 300 Hz is generally no problem due to the wavelengths of low frequencies. As you go up in frequency the problems start, unfortunately right in the mid range is where it can begin to be a problem. It is much the same reason that some people argue that center channels are more trouble than they are worth.... |
After hearing some outstanding line arrays, I totally understand why people like them. I am about to get a just released line array from a manufacturer for an audition. I was worried about combing as well, but the drivers are small and quite close together, so I suspect at normal (not nearfield) listening distances this should not be a problem. I'll post back in a few weeks with some initial thoughts, but at 16 ohms, (perfect for my OTL's) and no crossover, I'm thinking this might be an ideal speaker, (for me anyway). |
Emailists, I use Atma MA-1s with mine and the arrays are custom wired to yield 13 ohms nominal, 10 ohms minimum. I wasn't prepared for the difference that proper impedance matching makes with OTLs. You are likely in for a treat. As for comb filtering, diffraction effects manifest in all manner of speakers - even single driver/baffle interactions occur. Not unlike our listening rooms themselves. It is what we perceive that matters. I hear the bass nodes/nulls in my room quite well, ameliorated as best as possible with traps and PARC. Comb filtering in the "line array physics" sense is imperceptible in my setup. FWIW, I sit 10-11 feet back. |
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