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Choices, choices. With my personal arsenal of headphones it took reason and restraint to keep this assignment on track. My main focus on the Ortofon eQ7 as quality IEM and the small on-ear Focal Spirit One was informed by the obvious. The RxMk3b—henceforth Three—is portable. In that capacity most folks will run cans suitable for outdoors use. Those serious head cases who'd do otherwise would then relate to my T5p Beyers with balanced and single-ended leashes and the über-sized Audez'e LCD-2 likewise in two wiring flavors.

For amp comparators I had two of Ken's previous efforts - his RxMk2 aka the Two; and the amazing sub miniature valve-powered The Continental from that model's first run. For full-blown insanity which I privately call the triple sandwich—or the brick without the shit house—I had the Cypher Labs Algorhythm Solo iPod converter. This could piggyback any of the amps, take Apple's D/A conversion offboard and in turn insure that your portable rig stacks up (arguably rendering it somewhat less portable as a result).

Three vs. Two. This was an exercise in diminishing returns. No Two owner should suddenly feel disenfranchised as third-class citizen despite the differences in raw drive, urgency, grippiness and bass power. The Two was a bit mellower and more laid-back. On the right material—say Polish seductress Anna Maria Jopek—some might in fact fancy how by comparison that character telegraphs as minor softness or warmth and how these attributes contribute to a sense of greater distance. The Three plays it rather closer to the microphone. This tightens the musical weave, creates a bottom-up sense of the tunes held aloft by bass as the foundation and as such sounds the more close-up, immediate, massy and gonadacious even when its bass control remains at zero

That control is primarily a focus shifter. Engaged to varying degrees it moves the tonal center downward in a nicely subtle manner that's wildly different from the usual hit-you-over-the-head tone control. Shifting musical gravity downward creates a subjective soothing action on the treble. Poorly recorded Pop which you love regardless—I have an affection for saucy but brightly recorded Arab Pop like Wael Jassar, Amr Diab, Fadl Shaker, Elissa Zakaria Khoury & Co.—becomes more palatable. Your staying power increases and your indulgence lasts longer. That's very practical. It allows for a variable injection of some strategic warmth without the usual impact on grittiness and control. Back on Pop with its trademark upper bass energy, that can be built out a bit to create higher perceived drive and with it a stronger sense of grooviness i.e. that proverbial rolling stone which gathers momentum. Diminishing returns kick in with easy loads like my Beyerdynamic T5p. Such a smart headphone designed with portable devices in mind minimizes the amp differences.


Three vs. Continental. This became an exercise in tonal balance and radiance. The Three was the generally more lit up. It was fresher, more energetic and radiant or pressurized from the inside out. Transients were sharper, plucks pluckier, pops poppier, outlines firmer. The Continental felt demonstrably slower - more meandering burbling brook than rushing rapids. Its transitions were more watercolour and less separated/teased out in how parallel or overlaid events got differentiated. With the Three top-end extension and presence-region weighting also were stronger. In a nutshell the latest Rx prescription seemed the more highly resolved. Like a more powerful microscope it magnified down to lower layers inside the musical mix.

Though it would have neatly fulfilled popular expectations if the Continental came out ahead on tone in its saturation of colors and richness or density of 'chewable mass', this plainly didn't prove out. Whilst I would grant the Continental a modicum of extra sweetness, this didn't extend to superior tone per se. Here the Three actually had the more fully developed harmonic envelope to sound more vibrant. As such it better feathered out the occasionally slightly raspy gravelly attributes and coquettish quivers of Samba super queen Alcione's saucy vocals for the sexier vibes. To overdraw for character emphasis, the Continental was Audez'e to the Three's HD800. The Three's bass control meanwhile was a proper after-market leash for the Sennheisers to drop their testicles into greater sonority.


Though professional cynicism is supposed to mistrust a maker's self-salutary 'best we ever made' statements, the Mk3 straight—single-ended in/out, zero bass boost—really did trump the Mk2 and original Continental. With that settled, it was time to hone in on greater descriptive details. For those I defaulted to full-size headphones and the Cypher Labs Algorhythm Solo for the best ancillaries at my disposal. Time for the brick; balanced versus standard; and boostiness of bass and lower midrange vs flat.
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