PMC DB1i loudspeaker
PMC user-endorsers include artists like Brian May of Queen and Robbie Williams (the latter more popular in the UK than in the US), among dozens of other celebrities listed in the company's sumptuous, full-color brochuresStevie Wonder, Peter Gabriel, Coldplay, Kraftwerk, Brian (sic) Ferry, Prince, etc.though whether these artists actually own PMC speakers or have had their albums mastered at studios that use them isn't specified. The list of those studios is more impressive: BBC, Emil Berliner, Capitol, Chesky, DreamWorks, JVC Japan, Warner Music, and so on. A two-page spread in one PMC brochure features an endorsement by Fluid Mastering partners Nick Watson and Tim Debney, both formerly of Townhouse, a name familiar to vinyl enthusiasts who spend their spare time perusing the dead wax surrounding the labels of LPs: in the photo, perched atop their mixing desk, is a pair of DB1is being used as nearfield monitors.
But the pro-audio connection makes sense: the initials PMC stand for Professional Monitor Company. Founded in 1990 by former BBC engineer Peter Thomas and a business partner, PMC is better known among audiophiles in the UKwhere it has far better retail distributionthan among their American counterparts. Thomas, who in his brochure photo looks like a cross between Meatloaf and Ozzy Osbourne, is not at all shy about pronouncing himself "arguably the world's smartest loudspeaker designer...and a truly obsessive audiophile." Shades of the "genius of Matthew Polk"!
Like virtually every other PMC speaker, the compact DB1i uses a variation of transmission-line loading of the woofer's backwave to reinforce the speaker's low-frequency output rather than the more commonly used ported or sealed-box approach. PMC calls it Advanced Transmission Line (ATL), Bose calls it Acoustimass, and my parents' old Stromberg-Carlson console called it Acoustic Labyrinth. All of the speakers designed by the late, great Irving "Bud" Fried used transmission lines as well.
The particulars may differ, but basically, in a transmission-line speaker, the driver is at one end of a long tunnel damped with acoustically absorbent material designed to retain the backwave's upper-bass and higher frequencies, while the lowest frequencies emerge in phase from the vent at the other end of the tunnel, which in the case of the DB1i and other PMC speakers is at the baffle's top rear. The claimed advantages of such a system over a ported or sealed-box design of the same size include better driver control over a wider frequency band, thanks to consistent air-pressure loading, and thus lower distortion, higher SPLs, greater bass extension, and consistent frequency response regardless of listening level.
Though the DB1i is only 11.4" high by 6.1" wide by 9.2" deep, the transmission line's effective length is 5.5 feet. The driver at one end of that line is a proprietary unit with a 5.5" doped paper cone and a cast magnesium alloy basket, crossed over at 2kHz to a 1", ferrofluid-cooled, soft-dome tweeter made by SEAS. The moderately well-braced and damped cabinet weighs just under 10 lbs. The DB1i's claimed frequency response is 50Hz25kHz, its sensitivity a moderate 87dB/W/m.
Forgive my skepticism as I jacked up my +400-lb Wilson Audio Specialties MAXX 3 speakers, replaced their spikes with casters, rolled them out of the way, substituted the little stand-mounted PMC DB1is, and muttered, "This is not going to be a fun few weeks."
No point in driving the PMCs with my 1000Wpc Musical Fidelity Titan, I figured. Nor did it make sense to use the Music Reference RM-200 tube amp, driven by the darTZeel NHB-18NS preamp ($29,000), though I did listen that way for a while. Instead, I pressed into service a totally rebuilt Scott LK-72a tubed integrated amplifier, ca 1960, that outputs about 35Wpcand an old Musical Fidelity A1 Collector's Edition integrated that runs hot, and whose 40Wpc sounded exceptionally sweet through the PMCs.
A Meridian Sooloos Music Server was the main source, with Musical Fidelity's budget V-DAC D/A converter ($299), which has gotten rave reviews worldwide, and which John Atkinson told me measured almost as well as the dCS Scarlatti DAC (though you can be sure it doesn't sound quite as good). I also unboxed an old Ariston Icon turntable and tonearm fitted with a Shure M97xe cartridge and ran it into both integrated amps' phono inputs. The PMC speakers' double sets of binding posts permit biwiring, but I left the gold-plated links in place and ran a single set of speaker wires.
In all of these choices, my point was to use modestly priced sources and electronics with a pair of small, moderately priced speakers, and that extended to using a pair of generic, lightweight, MDF-and-metal speaker stands instead of more massive and expensive ones.