Polymer Audio Research Speaker

On May 12th, I attended the demonstration of the Polymer MKS loudspeaker by Polymer Audio Research at a meeting of the San Diego Music and Audio Guild.  I was glad to be able to attend this meeting if for no other reason than it was the first audio society meeting I have attended in over two decades.  At one time, and for about 9 years, I was the President of the San Diego Audio Society.  That was from about 1982 to 1991, and I haven't attended an audio society meeting since.  Not by choice, though arguably by laziness.  I moved to San Antonio Texas in 1992 and there hasn't been an equivalent organization here that I was aware of.  The only purist audio store in San Antonio is that of Galen Carol, who opens his home to prospective audio shoppers by appointment only.  The local Bjorn's dominates audio and video storefront space at the high end, but is primarily oriented to home theater rather than audiophiles.  There was a purist store called Concert Sound from which I bought a Linn turntable in 1998, and the owner expressed interest in having me operate an audio society here, but the store closed sometime not long after I bought the turntable.  Speaking of laziness, even when I was an audio society President (I think I was chosen or chose myself by default as the original organization created by Ike Eisenson was otherwise crumbling) I did very little, mainly just printing announcements for meetings that were mostly arranged by Bruce of Stereo Unlimited, one of the most well known high end audio stores in San Diego.  Even then, I rarely talked to Bruce directly, but instead had details provided to me by my friend and brother-in-law George Louis.  After I left San Diego, my friend George has retained ownership of the San Diego Audio Society name, but the more functioning successor volunteer organization is the aforementioned Guild.  So for me this was a reunion of sorts.

The location was an incredibly beautiful home at an incredibly beautiful spot on the shoreline at the southern edge of La Jolla, having a commanding view of Pacific Beach to the south.  The meeting was held in the living room which was joined with the kitchen and dining area in a unified space surrounded on two sides with large windows showing the surrounding views.  Virtually all the exterior wall space was covered with large super premium unscreened windows with no curtains or blinds.  I would guess the room to be about 40x25 feet or so, nearly as large as my entire house.

As George and I arrived just before the official starting time, the people from Polymer Audio Research were busy trying to get decent sound by slight adjustments in the speaker position, and removing hum apparently apparently picked up or caused by the speaker wire, which was two large separate conductors for each wire.  By the time the meeting started, the hum problem was mostly fixed, but the sound had not been well optimized.  As Roger and I agreed, they probably should have allowed a whole day for proper setup.

While the overall presentation had some good points, and the speaker itself seems to have many virtues, the sound was far from perfect.  It varied a lot by position in the room.  During the setup phase, somebody said that the best listening position was standing behind the sofa, and that was later repeated.  Well that position did seem to solidify the bass a bit, though the bass was irregular everywhere in the room (surprising for such a large room).  But the behind-sofa position on the center axis was one of the worst locations for a pleasant midrange.  From that position, the midrange was hazy, ill focussed, recessed, and slightly edgy.  The midrange was much better sitting on the sofa itself on the center axis, or even leaning forward a foot or two.  One of the key factors seemed to be the listening height with respect to the tweeter axis.  On or below the tweeter axis, the midrange was best, it quickly became unpleasant above the tweeter axis.  And all the listening positions from the center of the sofa on back were too far back for correct imaging, an proper listening triangle would have been about 4 feet in front of the sofa.

The bass had a different set of irregularities at each position, being slightly more forceful overall behind the sofa, but not really better overall.

My take was both a problematic room and a not-quite-perfected speaker.  I suspected the speaker had crossover and baffle related issues that tend to give it high frequency irregularities above the tweeter axis and edginess.  Notably the baffle seems truncated at the top, diffraction might be improved by extending the box (and the inward curvature) up by another 3-9 inches, more of an egg-shaped top.  About the crossover I don't know what needs to be done.  I suspect physical driver time alignment would help, or anything that improves performance above the tweeter axis without compromising it elsewhere, and perhaps adjusting tweeter level lower.  The people from Polymer audio said the crossover was intended to be very steep, but implemented with few parts.  Perhaps they chose the wrong tradeoffs here.  Crossover design is an art, ultimately like violin making.

While making these guesses, let me say that the room was unremittingly hard, with all ceramic, glass, wood, and plaster surfaces, and that huge number of identical windows.  Such a room might be better designed with each window to be slightly different to eliminate shared resonances, acoustic absorbers at key points.  I see the homeowner has a room correction system, which was not used for this demonstration; Polymer audio brought their own playback system including amplification--Linn amplifiers no less or more.  The amps might have contributed a tiny bit of edginess to the sound.  Further, a key factor was that the vaulted ceiling reached a peak in front of all listening areas.  This reflects all manner of delayed sounds to the listeners, smearing the image.  Vaulting running along the axis of the speakers is *much* better because it lacks this problem.  All manner of damping at the peak is possible (but maybe not visually acceptible) and also, what I did(!),  move the listening position in front of the peak.  That also combines with a flattened listening triangle, subtending about 75 degrees from the listener to the speakers, and a 4 foot listening position to 8 foot high speakers...so the speakers (not the room) dominates--that's what I did to mitigate my transverse vaulted ceiling.  Well the owner of this home could do something like that by ditching the coffee table and putting chair much closer to the speakers.  Actually...his speakers were further back (up against the back wall) and farther apart, subtending a better angle and possibly getting some useful bass augmentation.

Polymer Audio Research made the point over and over of using the best parts available in this speaker, and I don't doubt it.  But always, it's always the design that counts foremost.  Polymer Audio Research is a relatively new company, and perhaps they haven't learned the best way to design yet.  I'm not saying I know the best way either, but I know I've made a lot of mistakes, and it took even longer to realize I made mistakes, so at least one principle is...it takes time and experience.

On the plus side, the speaker was clearly undistorted even in this large room, a testament to the driver and enclosure quality, which IMO is worth the price in that you are getting what you are paying for (you are just not getting the performance it should be capable of, IMO, but this was not a fair test either).  In such a large room, it's nearly a miracle for such a compact speaker, with two small woofers, to fill it as well as it did (pretty well, with noted room-related irregularities, and not sub 30 Hz).  I don't think a speaker like this should be used without subwoofer in such a large room, but a test like this shows it should be able to handle smaller rooms with ease, if you can stand (or better, sit) the way it sounds.