FEEDBACK ONLINE - ISSUE 38
The Amazing German Physiks Speaker: Model PQS-202 - New Rules, a Review & Essay
All images courtesy of German Physiks
Speakers and Sound-Staging
Throw all your ideas about loudspeaker design out the window for half an hour and read this!
I am asking you for the teleological suspension of disbelief. Consider this as an attempt to explain some natural wonder, such as a volcano in the middle of the ocean that is building an island by discharging hot mud. It has never been seen before. The scientists are having trouble describing its activity. [See: "Two Years On, a Mud Volcano Still Rages—and Bewilders"; Science, 13 June 2008, Vol. 320, p. 1406.] Similarly, what we have here is a speaker for review that is so great sounding, so unusual, we may have to develop some new concepts, a new vocabulary, to describe it. To illustrate my last remark, consider this from a recent Stereophile on-line newsletter:
...though truth be told, we're still a long way from replicating reality – and will never do it with just two channels.
Like the teams of scientists studying the "Mud Volcano," some audio reviewers have trouble with a new concept. I'm willing to accept that of someone who's never heard the German Physiks line of speakers. In particular I take exception to the assertion that the audio industry will never be able to replicate reality "with just two channels." I might have said the same thing before I learned what these German Physiks speakers are capable of. So, Stereophile, you are forgiven.
Before I go on with the nitty-gritty of a standard review, I'd like to examine a few things that have just come to my attention in a "TAS Interview With Bob Carver" (TAS, August, 2008, p. 28). First, Carver cites Harry Pearson's seminal article, "An Essay on Imaging" (TAS Issue 18) to establish sound-staging as being (along with wide frequency bandwidth, and wide dynamic range) among those performance characteristics that define "great sound," that encourages listeners to immerse themselves in the musical experience in order to receive its full emotional impact. Carver also cites Henry Kloss's dictum that, "If you get that octave right [actually, the two octaves centered about 300Hz] ...the rest of it [the sound-stage] falls into place." Carver sums up with, "Henry Kloss ... taught me that the sense of acoustic space existed primarily in what is now called the 'Henry Kloss psycho-acoustic octave.'" Audio designers and audio critics are very alert to how well a system can replicate acoustic space in the listening room, and listen to this region (150-600Hz, roughly D below middle D, through D above middle D) with great care.
Knees and Slopes
In many ways the German Physiks PQS-202 speaker far surpasses conventional three-way systems of yore, upon which it is nominally based. It is an omni-directional system, with a conical driver, reminiscent of the Walsh driver, that handles the upper six plus octaves (that's 300Hz-24kHz, the midrange and tweeter of a conventional speaker without a crossover network and its attendant distortions), with a 12" "sub-woofer" that plays from about the lowest frequency a given listening room can support up to 100Hz, and a 6" "mid-woofer" that is rolled on at 100Hz at the bottom, and rolled off at 300Hz at the top. More specifically, the 12" driver has been measured at -0 dB at 35Hz, where it begins to roll off at room-dependent rates. Some photographs below illustrate the speaker's driver placement.
Mode of Sonic Presentation
The mode of sonic presentation of this German Physiks (GP) speaker PQS-202, with the lower mid-range driver firing up toward the ceiling, with the two woofers firing sideways and at each other, and the inverted ice-cream-cone shaped conical mid-tweet driving the rest, creates a mode of presentation of the sound field that is quite different from those of most front-firing loudspeakers that have their drivers "in-line" on one baffle. With the best in-line systems (like my "Big Dude"), where the phase and gain for various combinations of drivers have been patiently worked out over decades in the cross-over, the sound-field can be very precise. You can pick out a single instrument, anticipate its entrances, and with your eyes closed point to where that instrument will enter, and it does. I have come to view this as an artifact of the recording process and not at all a replica of my experiences in the symphony hall.
This ability, a parlor trick like touching your nose with your eyes closed, matters much less with the GP. The sound stage presentation is larger (due to the many reflections it is designed to create), hence less artificially precise. When an instrument enters, it is "more or less" in the right spot, very much as it sounds in my favorite acoustic room, Baltimore's Meyerhoff Hall. That is to say, the PQS-202 might be more accurate in that it is "more realistic" in terms of creating the illusion of having moved the living, breathing musicians from the symphony hall to your listening room. In a concert hall there are reflected sounds that bounce off the ceiling, the side walls, and even the back wall. The GP does an excellent job of directing some of the sound waves off my nearly eleven foot ceiling, and off my lath and plaster side walls, and even though a great deal of information comes from the "front" of the speaker, the many room reflections make a pair of them seem to create a much more complex sound field..
Frontal (in line) or Omni-Directional
After a few weeks of having them around, becoming accustomed to their sonic presentation, one might see how this type of loudspeaker has secondary benefits. Owing to its omni-directional mode of presentation, the GP has no particular sweet spot: rather, since each listening spot receives a great deal of first arrival sounds, you might say, "every seat is a sweet spot." Omni-directional dispersion does this, while direct frontal (in line) speaker mounting on one baffle does not, or not nearly as well. Having every seat a sweet spot doesn't seem like much, but this allows more than one person at a time benefit from the electro-mechanical magic of reproduced music.
I'm not sure you'll get enough information from the photos. The DDD driver, being conical, radiates in a circular, quasi-spherical pattern, spraying (outward and upward) mid and high frequencies about 270 degrees off all the reflective surfaces. The 6" woofer fires its mid-bass information upwards in a spherical omni-directional pattern, bouncing its waves off the ceiling and walls. The woofers fire from the sides of the cabinet, aimed at each other about seven feet apart, as if to cancel each other. What they actually do is this: the bass waves, that also radiate spherically (woofers don't beam), send sound-waves out from each of the two woofers that bang into each other like this <0)) ((0> as seen from the front. This resembles the dot-product when two vectors collide (for those of you who remember your vector analysis).
The results are (partially, as we are not examining the upward vector) two new forces; one pushing the bass wave backwards, while the other forces half of this summed wave forwards towards the audience that might be typographically represented like this <0))^((0> where the upwards pointing karat represents the wave that goes forward and backwards, (forward toward the listening area, and backwards toward the wall at the rear of the speakers). The forward wave reaches the listener a little before the back wave which bounces off the wall behind the speakers. As a result, the audience hears this speaker arrangement by hearing all three drivers acting together as if one big omni-directional, which is what a group of musicians performing in a listening hall is. The geometry of this loudspeaker, the angle of the diffuser behind the DDD driver, the knees and slopes of the crossover, have all been developed with extreme patience by GP, as an assault on no-compromise excellence.
Ad Hoc Listening Panel Responses
The German Physiks design team has succeeded. One member of my ad-hoc listening panel, Alan Shapiro (a longstanding audio hobbyist), said: "Given the wide range of the mid-tweet driver in the GPs, the entire speaker mimics the sonic 'integrity' of a single driver speaker system, like the Lowther." Another, Paul Loeschke (a C-SPAN technician and audiophile, with decades of experience in Pro PA systems), said, "I can't remember ever hearing a speaker produce such a convincing image of musicians in the room." A third, Erik Stahl (a symphony orchestra musician), said, "While playing Mahler, the ability to maintain instrument voice differentiation, independent of the volume each is playing, and with various degrees of complexity going on; or, the ability to minimize masking—is outstanding." These comments (with a little of my editing for publication), were unsolicited.
If the opposite of sweet is sour, I'd say there are no sour-spots in my music room when listening to the PQS-202s. The whole room, like a great sounding concert hall, say, Vienna's Grosser Musikvereinssaal, offers itself as a large sweet-spot, though one can still make out instruments as being left, right, or center (even if you sit across the room), can hear the various instrumental "lines" in complex music (like Bach or Mahler), can pick out and follow certain instruments that have a momentarily dominant part—even isolate supporting instruments—with minimal masking.
In other words, the arrangement of sound in the room does away with certain concepts we usually employ in evaluating loudspeakers. There is no sweet-spot, per se: The whole listening area, of itself, sounds sweetly. There is no specific feeling of the back wall, or the ceiling height of the recording venue: The orchestral instruments' sounds just seem to float in space. The sound comes from everywhere at once, factoring in reflections, and the experience of getting up to change a still-playing CD is like moving among the instruments. Furthermore, if someone gets up and walks across the front of the listening area, there is only a small decrease in loudness while he/she is momentarily in each listener's line of sight to a speaker. There is no reason for concern about instruments being wider than the space between the speakers, though that does happen, with well-engineered recordings. When it happens, it's no big deal; it's just the way music sounds in a symphony hall, or an opera house, or a jazz club.
The "audiophile rules" for evaluating single point-source drivers (like Lowthers), or vertical line-source arrays (like Pipe Dreams), or bi-polar sources (like Quad electrostatics, or Magneplanars), do not apply! As TV comic Bill Maher likes to say, it's time for NEW RULES, though I will let other, more adventurous, souls undertake the tasks of developing new concepts and new terminology.
Two of these GP (German Physiks) omnis hang an image it took six channels of Verity Parsifals set up in the Chesky Records' master mixing room that I reported on some years back. And, in a manner similar to the then-Chesky system's sonic thumb-print, the sound doesn't hang exactly: it floats. It floats no matter whether you are standing or sitting, or which seat you have in the room, because owing to the radiation pattern, wherever you sit—each individual speaker is, effectively, in a straight line facing you. That is to say, the speakers do not flashlight beam the sound waves at the one "sweet spot" (as most point-source, or vertical-line arrays do); the earliest arriving moment in the music is always omni-directionally beamed directly at every seat in the listening area. There are no bad seats; only good, better, and best. No seat in the room is ever off-axis. I guess I'm saying, this is one unbelievable speaker, at least in regard to—imaging. If many new speaker designs have mastered wide bandwidth and wide dynamic range, it is realistic imaging that is the measure of superior sound reproduction among the elite speakers.
At my home (the little beach shack on the shore of the Chesapeake Bay, where every day we say, "Surf's Up, Dude"), we were constrained by some serious problems of room layout and such. For example, in the corners of my listening room I have very large Klipsch horns housing 18" Hartley woofers. These cabinets consist of ornately carved Mexican wooden panels on the outside, and a plywood horn on the inside. They are gorgeous, if you have a taste for objects designed in that South American way. The K-horns' front panel were copied from a door on display in the Museo des Artisanos in Guadalajara. They must be one of a kind. But I digress. I didn't want to move those, for fear of damaging them. Then there was my equipment rack that housed all my "front end," and couldn't be moved without great difficulty. So the optimum placement in my medium-sized listening room was compromised, somewhat. But, they still sounded great, some said, even better in the adjoining room. I enjoyed having them around for about ten weeks. I think I couldn't have evaluated them properly with much less time to get used to, and into them. Thanks Chris.
Risking Life and Limb for Art
More recently, Chris Sommovigo, the importer of the German Physiks PQS-202, arranged for a command performance for the loosely configured Northern Virginia Audio Club (NOVAC). He also arranged for David Berning to furnish the electronic front end. So one Saturday morning we packed the heavy mothers into their custom designed crates and set out through a misty morning to Dave Berning's house in the not-too-distant D.C. suburbs. We picked him up in Potomac, Maryland and proceeded to the listening room of Jeff Fox, the owner of "Command Performance AV" in Falls Church, Virginia. By this time we were driving through a "tornado watch" and experiencing thunder, lightening, heavy rain and hail, all the ingredients for tornadoes. The force of the storm increased as we proceeded on our course. We passed the time whistling past the graveyard and swapping audio stories with Berning, who has a gentle, ironic way of putting things. Besides risking our physical selves, I figured we also risked the van and about $100,000 worth of gear. When we arrived safely at our destination, we each exhaled deeply. I licked my chops in anticipation of hearing the speakers in a room approximately thirty feet by twenty-one feet, driven by Berning's truly world class amplification.
Big Room Sound
It was a revelation. First, Chris went through a few iterations with the placement. After removing some of the side-walls' damping material, and spreading the speakers farther apart than they were in my room, and ramping up the treble control on the back of the cabinets four notches, the speakers "clicked in." It is important here to point out the treble has its "knee" and 8kHz, so no fundamentals were boosted. All that was boosted were harmonics and air. I mean, Chris found the optimum tweeter setting and placement for the speakers in the room: about seven or eight feet from the rear wall, about six feet from each of the side walls, which left about nine feet between the woofers (or about two feet wider than in my room). I thought from mid-range up they sounded about as they did at my place (wonderfully) considering sound staging and all seats within the sweet spot. And the bass "got down" and boogied to the deepest notes when tested. I know there are notes lower than a bass guitar can produce, and tickling the speaker placement to optimize woofer performance could deliver some improvements, like on the deep pedal notes of an organ, or a synthesizer; but, that afternoon the PQS-202 did everything it was called upon to do.
It was impressive: it could play very loudly and still retain the delicacy of the software with which I was familiar—Diane Krall's The Girl in the Other Room, for one example. It could play pretty softly and retain the sparkle of the drummer doing some brush work behind the singer, with an occasional cymbal "ting" thrown in. The "test CDs" were mostly female vocalists of the current generation, and some of the recordings represented the best the industry could produce. The speakers seemed to make all the singers sound better (more lovely and free of recording artifacts) than the CD owners were used to. There were more than one or two unsolicited remarks to the effect that the speakers were what I call, "soprano friendly." Moreover, when I heard the familiar growly, phlegmy voice of Louis Armstrong (Louis Armstrong and Duke Ellington, Verve #) I noticed that even he sounded more agreeably lifelike. I guess we'd have to say these German Physiks PQS-202 speakers are "growl and phlegm friendly," too.
Matching Amps and Speakers
I should address my selection of the best-amplifier-for-these-speakers at this point. I have lots of amps hanging around the house. Some "golden oldies," and some just plain "oldies." Chris Sommovigo seemed to think the speakers required a lot of muscle to sound their best, so we started out playing the German Physiks PQS-202's on my Parasound (John Curl designed) rig, with (very highly thought of) Parasound's Halo JC-2 preamp (known for its sound-staging) driving a pair of equally esteemed Parasound's Halo JC-1 amplifiers, 400-watt monoblocks (known for their sweet and relaxed presentation). This setup produced a highly detailed, warm, very relaxed sound. It could play blues, or hard rock at excruciatingly loud levels without compressing the sound or the image, and it was pretty smooth and suave. When we substituted my pooged (1953 Williamson type amps rebuilt from the transformers up) Fisher 50-A, 45-watt rated monoblock amps, and ran them full range, the sound was magically transformed. It became what I call "warmer and more lifelike," and what Chris called "the most suave amp" he'd heard through those speakers.
'Tis a pity we never had a chance to A/B compare the Fishers to the Bernings; but if my memory serves, the Berning's sonic balance emphasized the trebles a bit more, and so were not quite as suave. I tried pooged Marantz 8B's, run in triode mode, strapped to mono (measured at just under 40-wpc), with recently swapped-in "Stealth diodes" in the power supply, and they sounded a lot like the Bernings; detailed, analytical, with very high-resolution, though obviously not able to match the Berning's 250-watt output. I also tried another transistorized amp, a "Son of Ampzilla;" which was pooged by James Bongiorno, the designer (and then a little more by me), to see how a high quality if moderately powered (60-wpc) amp would do. The Fishers, though at a lower power rating (45-wpc, measured at just under 50-wpc), could play noticeably louder before they got into trouble or soft-clipped. The Fishers played at least 3dB louder than the Son, or (another way of putting it), the Fishers delivered 100-watts on peaks. In this case, the tubed amp delivered more than the transistorized amp of approximately the same rating.
From this experience I'd say, the German Physiks speakers PQS-202 have a tendency toward brightness in medium-sized rooms, and they seem to like tubed amplifiers of a warmer, more suave persuasion. I understand Kara Chafee, of de Havilland audio, has designed a version of this particular type of Williamson push-pull amplifier, a departure for de Havilland, which had previously specialized in Single Ended Triode (SET) amps. They call it their 50-A as an hômage to the Fisher 50-A, displayed on the home page of their website: http://www.dehavilland.com. It is quite similar in most regards, a souped-up Williamson-type amp with good modern parts. I haven't heard it yet, but from what deHavilland's website reports, it sounds quite similar, too. The Fisher 50-A's were not perfect with the 202's. With the Fisher 50A tubed amps their tone became "very rich" and "warm." The deep bass instruments were less distinct from one another while playing at the same time (because of the tubed amp's lower damping factor), but the low and middle brass instruments were gripping.
The answer to the under-damped Fishers' bass problems was apparent. I had to bi-amplify, which, as it turned out, was easy to do. The speaker is set up for bi-amplification. All I had to do was disconnect the wiring harness that coupled the sub-woofer to everything else. Then I connected the signal from my pre-amp to my Shadow electronic x-over. I routed the crossover feed from 100Hz-down through a pooged Adcom model GFA-555 transistorized amplifier to the 202's sub woofer; and from 100Hz-up through each Fisher 50-A and to the 202's 6.5" mid-woofs and the conical DDD tweeter/midrange drivers. Now I could "manage" the gain of the bass a lot better (and play around with woofer angles), and the tubed amps could be more relaxed—not having to produce deep bass. The whole system cleaned up and tightened up a notch.
I found this was a nearly optimum setup for this speaker: relaxed tubes on the top, highly damped transistors on the bottom. The bass cleaned up a lot, but still managed to "get down" and keep its "slam." Bass response was far less woolly when driven by my pooged Adcom GFA-555. The various instruments of similar timbre (bass-drum/kettle-drum, bass-viol/cello, bassoon/contra-bassoon, electric-bass/electric-guitar) were more easily differentiated when playing at the same time. I also could adjust the gain for more bass at lower listening levels, and less bass at higher levels. Bi-amplification allowed me to gain better bass management, less masking of lower frequency instruments, cleaner and clearer perception of low frequency instruments' performance, and less stress on the tubed Fishers. And, after I'd found the speaker/amp sweet spot and set it for my favorite listening level, I just kicked back and listened. It wasn't like discovering my CD collection over again: it was like being in the place where the recordings were done for each album!! What did Johnny Mathis sing? Oh yeah. "Wonderful, Wonderful!" That about captures it.
A Few Caveats
There are a few "minor" things to deal with. One is the brightness control. This is a carefully designed two-dB per-step switch, with its knee at 8kHz. That means there is a range of eight dB in four settings of more "air" and harmonics. You can goose the brightness up two notches (at plus 2, or plus 4dB), set the mid/tweeter's output at zero (or flat), or cut it to minus 2 dB. I can't stress this too emphatically: I think it will help optimize this German Physiks QSP-202 if you carefully match the speakers to a sweetly tubed amplifier. You might also consider some of the tricks of voicing the speaker: for example, using soft-sounding AC power cords, inter-connects, and loudspeaker cables. I've found you can get such cables in soft, flat, and bright if you find an audio dealer who is willing to work with you until you voice the system to your taste. It is worth the time, and it needn't cost much.
The woofers can be made to sound very, very good. They are already very good, and the speaker enclosures are very non-resonant. But it seems they are more room dependent than many traditional speakers. They are sensitive to placement and angling in the listening room, and unfortunately this means lots of trial and error, because every listening room is unique. At best, they have deep, non ringing bass. The woofers have been designed to act as a large omni-directional pair. But, as bass frequencies usually radiate in circular patterns, they will do well in a room with enough space for them, and the instruction manual may be only considered a point of departure. While Chris didn't say as much, he did suggest I rotate the speakers such that the woofers were at a 45 degree (rather than 90 degree) angle to the seating area. I tried his suggestion, and it helped the woofers improve a noticeable notch.
This is a speaker that needs a room to itself, and a good-sized "music room" at that, because it will overpower a too-small room. It can be made to thrive with judicious in-room tweaking. If the room becomes too lively, it may need added damping material (say, a colorful quilt, blanket, Persian carpet, or a "tapestry") added to the side walls, and perhaps the wall behind the speakers; or, it may need some absorptive materials removed if it is already overly damped with too much carpeting, drapery, and heavily upholstered furniture. If feasible, the system ought to be bi-amped, with an active (electronic) crossover, and the woofers ought to be driven by a transistorized amp with a medium to high damping factor. The rest of the drivers ought to be driven by a sweet tubed amp, of which there are many on the market. Speaker placement can be experimented with, requiring a strong back and some rubber cups to keep the bases from scratching hardwood floors. As I already mentioned, AC cords, speaker cables, and interconnecting cables can help voice this system to bring out the subtleties it is capable of retrieving from your favorite musical software.
This is not a loudspeaker equivalent of a "point and shoot" camera. You will have to fuss with it to get the final percentage points of performance out of it. Sometimes attention to the smallest things makes the biggest difference. These percentage points are there, they can be retrieved, and when the whole system "clicks in," they sound about as good as anything I've heard. Who was it who first said, "The devil is in the details"? Ludwig Mies van der Rohe? The German architect modified that old German proverb to read, "God is in the details." The approach to the divinity through music is implied with that. Through these German Physiks speakers, it was never more apt.
Now, a half-hour later, let me try to gather the threads. I'm old enough to remember when the Quad electrostatic speaker showed up in the U.S. in the late '50s. It had a truly revolutionary sound. To own a pair, as I did in the '60s, was to begin to learn the lessons of compromise. The Quad (an acronym that stood for its first Williamson-type amplifier—Quality Amp, Domestic—and became its corporate name) didn't make deep bass, had a single chair sweet-spot, rolled off the highs beginning at about 6K, and was not very efficient delivering about 86dB/one watt. And, as the competition was largely Klipsch horns, Altec "Voice Of The Theater" speakers, and others that made about 98dB/one watt, it was viewed as "problematic." But people like Mark Levinson and the SME Corporation's C.E.O., Sir Alastair Robertson-Aikman, figured out how to solve those problems by using the Quad electrostatic as a mid-range in varying number of pairs. The lesson being; if you want the best simulacrum of live musicians in the room, it's available—for those who are willing to make the necessary trade-offs. Two pair of the original Quads could deliver perhaps 102dB, maximally, and for short periods. But they sounded really great with my pair of Klipsch-horns and super tweeters.
If you are among those who are willing to make trade-offs, the first is price. The retail price of the particular speakers I've been discussing is about $44.5K. I say "about" because the dollar is so volatile just now. That amount represents a nice sized quality automobile. If you are among the deep-pockets crowd that sometimes read Pos-Feed, then it doesn't matter. For the rest of us, it matters. And if you have a modest income, and upon hearing these speakers you decide you can't live without them, German Physiks does market a unit that contains the speaker without the woofer for about half that price, and you could get a standard sub-woofer or two (all low frequencies distribute themselves radially) and figure out how to save a lot of cash. But your personal values are your personal values. How much does great imaging and state-of-the-art sound mean to you?
You'd have to have a liking for modernist styling, too. The speaker comes in various wood veneers, and it comes in space-age black. The black is actually hi-density-fiberboard, coated with a layer of fiber-glass for additional rigidity, and another layer of high-gloss epoxy for vibrational deadening. Since it's built like a brick ship yard, it weighs a bit more than it I expected. The fit-and-finish are exceptional. Its sensitivity to all amplifiers and cabling is unusual and makes me realize how many speakers are insensitive to that, and how they might be coloring the sound. The German Physiks PQS-202 loudspeaker seems unusually uncolored to me. Best of all, it floats a great image.
If my description floats your boat, and your pockets are deep enough, and you can afford a first-class front end plus cables, and your room is medium to large, then this might be the speaker for you. If you are merely interested enough to go to an audition of a world-class speaker that might be coming your way, you ought to get in touch with importer Chris Sommovigo at his email address, firstname.lastname@example.org. He can fill you in and keep you posted via email where his dog and pony show will be next. Otherwise, you'll just have to take my word. For information provided by the manufacturer, go to their website, http://www.german-physiks.com and you'll be able to see all their models—some less expensive, and others lots more.
I hope I've touched all the bases. Lord knows, I've tried to hit them in just a shade under 5,000 words. If you are among the few that stayed with me, thanks. Stamina still counts.
When you get in touch with Chris, be sure to tell him Max Dudious sent ya'.
What else can a fellow ask for but a loudspeaker that is "growl and phlegm friendly"?
(We should have played Tom Waits just to make sure ...)
You've managed to capture the PQS-202 Mk. II wonderfully, and I thank you not only for giving them the real-estate in your listening room for 10 weeks, but also for giving so much of yourself in the process of the review. The combinations of amplifiers, electronic crossovers, and cables you used to eek out the very last little bit of performance from these speakers should be very telling to your readers about the sincerity and sobriety of the man behind the pen.
A word about German Physiks loudspeaker models: With only a very few exceptions, any single German Physiks loudspeaker model is available in six different variants. Three cabinet finish/construction levels, each with two driver options. There are many wood finishes to choose from, as well.
The PQS-202 Mk. II that you had in for review is the very top iteration of that model, which means that its cabinet had additional reinforcement internally and was also reinforced by real carbon-fiber (not fiberglass, as you remarked). The speaker is then finished in many luxurious coats of hand-polished lacquer. The DDD driver is also of the carbon-fiber variety, which is an upgrade from the Titanium version of that driver (itself quite an astonishing performer). I call the version you reviewed the "Formula-1" variant, for all the luxuriant carbon-fiber adorning it.
While the "Formula-1" PQS-202 Mk. II, as reviewed, retails for $45,000.00/pair, the first variant of this loudspeaker retails for $36,000.00/pair (Oiled veneer finish with Titanium DDD driver). Four model variants exist in between the first model and the "Formula-1." As you noted, a PQS-201 version of this loudspeaker, sans subwoofer, can be had in six model iterations ranging from $18,500.00/pair to $26,000.00/pair depending on cabinet variant and DDD driver option (titanium or carbon fiber). The carbon fiber DDD upgrade extends performance at both ends vs. the titanium, covering additional bandwidth and providing just a little bit more sensitivity.
*For those interested in pairing satellite DDD loudspeakers to subs of their own choosing, the matching process requires a little more effort, but there are satellite models of the DDD driver starting at $11,790.00/pair (Troubador 40).
*For those interested in a one-way full range design (single driver DDD in a rear-loaded horn), the Unicorn models range from $18,500.00/pair to $26,000.00/pair for the full-on carbon fiber variant - which can produce LF into the low 30's and perform through 24kHz from a single carbon fiber DDD! Single-driver purists take note!
A word about the low frequency performance of the PQS-202 Mk. II: As you noted, the quoted LF performance on the PQS-202 Mk. II has a 0dB down point of 35Hz in a sealed cabinet. Given the proper room dimensions and proximity effect of the floor, it will produce the lowest organ pedal notes with aplomb. I suspect, in hindsight, some of the slight LF issues we experienced in your room might have been the K-Horn subs sympathetically resonating and damping the LF produced by the PQS-202 MK II. That said, I was very impressed with the sound we achieved in your space despite whatever placement-limitations we may have encountered.
Like all loudspeakers, the PQS-202 Mk. II doesn't live in a vacuum. Rather, it becomes part of a symbiotic whole with amplifier and attendant cables. Choosing well will deliver the best possible performance, of course. I was near awestruck at how well the Fischer 50-A performed with this speaker, lending a very inviting and three-dimensional suavity to the sound. Having brought these back home from their Mid-Atlantic adventure, I've paired them with the Vitus Audio SS-101 amplifier, which has proven to be one of my favorite matches for GP speakers. The amp grips the PQS-202 Mk. II with authority, but without brutish disregard for nuance and detail. I love the balance of the seductive midrange and clarion highs combining with the iron-grip on the low frequencies that envelop the listener and lend massive dimension to the soundstage and all its inhabitants.
German Physiks have accomplished something quite singular in this field in that they have created a loudspeaker that, when properly setup and paired well with mating electronics and cables, will project a simulacrum of reality limited only by the quality of the recording. This is largely due to the technical tour-de-force that is the DDD transducer.
I like that you've referenced Bill Maher's catchphrase to introduce the notion that the old rules do not apply. To evaluate a German Physiks speaker in the context of what one already knows (with regard to other driver technologies and arrangements) is to miss the forest for the trees. These loudspeakers represent an actual paradigm shift (in the purer sense that Thomas Kuhn intended rather than in the colloquial sense). To understand them is to forever change your worldview and expectations about what loudspeakers should do and how they should do it. The DDD operates in a revolutionary manner considered rather impossible from within the paradigms governing traditional (Theile/Small) loudspeaker engineering thought.
For the technically-curious, a thorough examination of the DDD technology can be found HERE.
On a more basic level I tend to think of German Physiks loudspeakers as being more accurate than most types, even other omnis, for a couple of reasons:
1) All German Physiks models use a very wide band, point source, bending-wave omni driver operating without significant phase shift over a tremendous bandwidth. By contrast, multiways will always be plagued by crossover distortions in the most ear-sensitive portions of the audio band, due to their need to use multiple drivers to adequately address that bandwidth. As the old saw goes, "There's no crossover like NO crossover," and while the Carbon Fiber DDD may sit atop a high-pass filter designed to roll it on below 250Hz (6dB down at about 150Hz), it operates crossover-free from that point upward through 24kHz.
2) The polar response of the PQS-202 Mk. II is somewhat similar to that of a cardioid microphone for it's entire operating range (cardioid thanks to the deflector behind the DDD, otherwise omni in the other non-deflector models), so chances are it is doing a better job than traditional multiways at decoding signal derived from the most commonly used microphone by mimicking the polar pattern.
In a symphony hall, when you close your eyes and listen to the music, there exists no "razor sharp" imaging - yet there is an undeniable organic presence that alerts or cues the mind of the listener to its authenticity. I tend to think that German Phsyiks loudspeakers decode this information from the recording more deftly than others, making the soundstage and imaging presentation more authentic to the ear when the recording contains the information to decode. They won't make a silk purse from a sow's ear, though, which indicates to me that they are not manufacturing the illusion, just projecting it clearly. The art of the recording and mastering engineers becomes very apparent through these loudspeakers.
With regard to adjusting high frequencies on the PQS-202, I wanted to be clear about the function here: This ability was developed in order to help the DDD adapt to certain room conditions. Because omni drivers use the room's boundaries to achieve their end, absorbent materials in the room can alter the overall response (this is true with any speaker, and more true with speakers firing into 4pi space). We removed as much of the absorbing panels in the room at Jeff Fox's NOVAC gathering as was possible, but there remained some on the back wall and some on the ceiling across the A/C ducting structure. As well, carpet can pull a lot of energy out of the air, and the front end of his listening room was well carpeted. The adjustment was made to compensate for those absorptions, but—as you indicated—it only affects frequencies above 8kHz, thus no fundamentals are boosted. Awhile ago I found this interactive frequency chart helpful to refer to: HERE.
I apologize for being verbose in my comments. I'm sure you must know by now how infatuated I have been with these loudspeakers and with German Physiks generally. Now that the honeymoon is over I can tell you that I remain in love. I have heard no other loudspeaker that can accomplish the 3-D virtual-reality feats that GP speakers seem to make routine work of. Suspension of Disbelief is no chore - you needn't squint your ears to grasp the wholosity of the experience (thank you, Gizmo, for the word). They wear their purity of purpose on their sleeves with no need for apologies or excuses. They simply make it easier to forget about the gear and immerse yourself in the music.
I would also like to say that, as always, I truly enjoyed your writing. You're not only very considerate as a reviewer, not simply very systematic about discovering the salient attributes of your quarry, not merely a generous host ... you write a truly mean read, and I always enjoy your work.
"...growl and phlegm friendly" - that could only be Max, and I wouldn't have it any other way.
Thank you for your Max-nicity.
The Signal Collection, LLC