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Srajan Ebaen
Financial Interests: click here
27" iMac with 3.4GHz quad-core Intel Core i7, 16GB 1.333MHz RAM, 2TB hard disc, 256GB SSD drive, ADM Radeon HD 6970M with 2GB of GDDR5 memory, OSX 10.8.2, PureMusic 1.89g in hybrid memory play with pre-allocated RAM and AIFF files up to 24/352.8; Audirvana 1.4.6 in direct/integer mode 1, Metrum Acoustic Hex, AURALiC Vega
Preamp/Integrated: Nagra Jazz, Esoteric C-03, Bent Audio Tap-X,
TruLife Audio Athena, Bakoon AMP-11R
: First Watt SIT1, SIT2, F5 & F6, Job 225
Speakers: Aries Cerat Gladius,
AudioSolutions Rhapsody 200, Zu Submission
Cables: Complete loom of Zu Audio Event, KingRex uArt USB cable, Tombo Trøn S/PDIF cable, VdH Pro 110
Ω AES/EBU cable
Artesania Exoteryc double-wide 3-tier with TT glass shelf, Rajasthani solid hardwood console for amps
Powerline conditioning: GigaWatt PF2
+ Vibex Two 1R DC filter on amps, GigaWatt PC-3 SE Evo on front-end components

Sundry accessories: Extensive use of Acoustic System Resonators, noise filters and phase inverters
Room size: 5m x 11.5m W x D, 2.6m ceiling with exposed wooden cross beams every 60cm, plaster over brick walls, suspended wood floor with Tatami-type throw rugs. The listening space opens into the second storey via a staircase and the kitchen/dining room are behind the main listening chair. The latter is thus positioned in the middle of this open floor plan without the usual nearby back wall.
Review components retails: €13.500/pr for high-gloss lacquers and veneers, €11.500/pr for satin

Gender bender. What do various Linæums including Audio Consulting's Rubanoide, the Manger, the Goebel, Shelley Katz's Podium Sound panel and the Ohm Walsh of yore, the NXT, Naim BMR and German Physiks drivers have in common? Pistonic transducers shun surface oscillations or at least claim to. These bending-wave drivers exploit 'em and live to tell the tale. From reading their small print, it appears that in fact they all transition from one mode of operation to various others. Over a variably broad band this includes pistonic. Yet what in a purely pistonic device would be considered a break-up mode—i.e. distortion and thus baaad—becomes legitimate desirable behavior in a bending-wave unit. Without getting into the small print of math and Physics which exceed my comprehension, it's fair to posit that creating a bender with linear performance over its chosen passband must be a rather complex matter. This wonky club includes flat types in bi- and monopolar flavors; curved types of either persuasion; and today's German Physiks whose hoary ancestor was one Yankee named Ohm Walsh. Dubbed DDD or Dick's Dipole Driver for its (re)inventor, it's a funnel-shaped omnipolar contraption. This steeply elongated cone has a spider/motor on one end and terminates in a rubber suspension at the other. Not just capable to push/pull like a regular dynamic unit, the same applied force also causes the diaphragm to flex and ripple. Bending waves. Though simplistic it illustrates the mixed general principle.

From it follows that this driver cannot be built into an enclosure as that would obscure its radiating surface. If it stuck out horizontally, you'd have zero direct sound, just pure reflections from ceiling and floor. The only places it thus can go are the enclosure top; or as a vertical armature attachment with up- and even downfacing units joined in the middle, perhaps even multi-paralleled for a line-source array whilst the main tower then could house equivalently stacked woofers in various configs.

Because their DDD is a wideband transducer, all German Physiks models thus are two-ways and most of them sport a downfiring woofer topped by a triple D. Firing out a box on both ends also neatly accomplishes matched omni dispersion.

This now segues us into today's review model. Its simpler cheaper Limited version runs in a rectangular box. The nattier dressed HRS-120 goes octagonal and fancy veneers or lacquers. The driver itself comes in go fast and go faster versions with a 0.025mm thick Titanium or 0.15mm Carbon fiber foil.

If for the HRS-120 we look at spec skewing between driver versions, we see that impedance remains unaffected (4 ohms for both) but that carbonated response hits 24.000Hz rather than 21.500; that power handling goes up by just a whisker and efficiency by 0.4dB*.

* "Sonically the Titanium DDD has a little better low-level detail but the Carbon has a more extended response at both ends and better transient response. You can drive it with big transients and it is very very hard to break. Titanium is more fragile and there is a possibility to break the diaphragm if you go crazy. For normal sensible use this is no issue. Also if you touch the Titanium diaphragm it will dent. This is unsightly even though you can inflict quite a lot of damage to it before there's any audible effect. Our crossovers curtail HF response since the Carbon otherwise would go to ~30kHz but it does become a little ragged up there."

The actual review pair at HighEnd Munich 2013

The high-pass filter remains at 240Hz for either driver with a 2nd electronic and ultra-steep 6th-order acoustic function to add to a very rapid exit at 48dB/octave. The woofer sports mirrored 2nd-order electronic/acoustic slopes for a 24dB/octave filter function. With the Titanium unit the accompanying bass unit is an 8-incher to net an F3 of 31Hz. For the Carbon this grows to 10 inches and 29Hz. Overall dimensions are a 32 x 32cm footprint (12.6") and 1.14m height (45") for both. There's also an HF adjustment of -2dB, 0, +2/+4dB centered on 8kHz with a notch filter and selected with a jumper above the speaker terminals. Efficiency is ~87dB and thus slightly less than the DDD would do solo.

Fender bender or gender mender? The most unimaginatively christened HRS-120 could seem like a Napoleonic sort: short of profile, thirsty for power. But lest we think temperamental—the Bonaparte reflex would— 360° horizontal dispersion from top to bottom promises good in-room bass behavior, non-critical placement in general plus democratic rather than dictatorial imaging regardless of seat. If that conjures up happy-happy notions of a small equally omni equally Teutonic Duevel Planet for chump change, check your wallet. You'll need at least €11.500 depending on finish. Hi-tech from a smaller German company who invested heavily into R&D doesn't come cheap. There's the need for amortization which presumably clashes with lower sales volumes, a shrinking market and globally stalled economics. Hence acquisition of even this small German Physiks model goes wildly beyond just paying for a fender bender. Whilst on rhymie pairs, lack of grill (like Marchisotto's old Alon models, this would have meant an unsightly inverted trash bin solution) may not make for a gender mender with approval from she who rules the house. But there's always the audiophile dungeon. Of course her hated must-sit-here-and-don't-move-yer-head thing has packed it too. With a proper demo to demonstrate the benefits of omni radiation (just don't play her your moldy audiophile demo discs), the top's techno look might become a proper décor blender. And now I've run out of silly enders. Time to get serious about sound.