Krell Resolution 1 loudspeaker
By Michael Fremer   •   November, 2004 Sometimes you have to make peace with a loudspeaker. You have to accept it on its own terms rather than ask it to bend to your sonic wishes, or to be something it's not. This is especially true when you're auditioning a seemingly endless succession of them, as I have this year. Like beauty-pageant contestants parading across the stage, all different-looking yet all enticing in one way or another, each speaker I've listened to of late has sounded different from the rest, and each has had a unique combination of strengths and weaknesses—yet each has been sufficiently "in the pocket" to paint a credible musical picture. Nonetheless, some required more bending on my part than did others, in order for me to believe the musical portraits they were attempting to create.

That was not the case with Krell Industries' Resolution 1. From the first minute I heard it in my room, I believed what I heard. I accepted its musical truth without reservation or accommodation. Over time, and the more I listened, I came to understand that immediate reaction, but to go from a stellar and in some ways singular performer, such as mbl's $45,000/pair 101E Radialstrahler that I reviewed last month, to Krell's $11,000/pair Resolution 1 and not be in some ways disappointed, is itself a major achievement.

Resolution 1
While most audiophiles think of Krell's Dan D'Agostino as an electronics guy, he began his audio career as a speaker designer, and was once the importer of Sonus Faber speakers. His continuing friendship with Sonus's Franco Serblin is what allows Krell to borrow directly from Sonus (and acknowledge the loan) the Resolution 1's grille of stretched rubber strings. But between Krell's Resolution series and the Sonus Faber designs, no other strings appear to be attached.

The 1 tops the Resolution line, which also includes a smaller floorstander, a bookshelf model, a center-channel, and a subwoofer. The 1 is a big speaker—4' 10" tall and weighing 195 lbs—yet its relatively slender (13") baffle let it fit comfortably in my listening space. The tall, graceful cabinet of MDF has curved side walls and a flat rear panel. It's nicely finished in an attractive veneer of opaque cherry (the only choice), and, despite its height, blended pleasingly into my listening room. Knuckle-raps over a wide area of the cabinet indicated that it's reasonably well braced; subsequent to that bout of self-bruising, I read that a subenclosure within the main cabinet houses the midrange and treble drivers.

Two custom 10" aluminum-cone woofers in a rear-ported bass reflex configuration anchor the design. These feature big motors to maximize control and minimize distortion, and vented voice-coils to increase power handling.

Above the woofers is, essentially, a three-way speaker turned on its head: on the bottom, slightly above the baffle's vertical center, is an iteration of Vifa's ring-radiator tweeter; above that is a 4" polypropylene-cone midrange driver, and at the top a separately ported 8" mid-woofer. The ferrofluid-cooled midrange driver features a one-piece cone and surround and a custom voice-coil former, while the mid/bass unit sports an ultralight magnesium cone and brass phase plug to prevent beaming at the top of its passband.

The woofer crossover point is 119Hz (via a second-order Chebyshev low-pass filter), while the mid-woofer driver has a second-order Chebyshev high-pass filter set at 118Hz and a second-order Butterworth low-pass at 422Hz. (The Chebyshev filter has a steeper cutoff than the Butterworth at the expense of some passband ripple.) The midrange's natural low-frequency rolloff is used for high-pass filtering, with a second-order Bessel high-pass filter added at 126Hz to improve its power handling at the bottom end of its range. A third-order Butterworth low-pass filter at 2860Hz restricts the midrange's HF response, while a third-order Butterworth high-pass filter rolls the tweeter in at 3550Hz.

In other words, the Resolution 1 is a complex, multidriver design of the sort that makes for interesting measurements and a wideband response, but often—though not always—disjointed, incoherent sound.

Installation and placement
When the Resolution 1s were installed, Krell's Bill McKiegan took great pride in showing me the four complex-looking crossover networks built up on 1/8"-thick glass-epoxy circuit boards. Each was packed with high-quality parts, including unusually massive inductors. McKiegan told me that Krell's goal was to pass as much power as possible through the networks in order to preserve the widest possible dynamic range of the 90dB-efficient Resolution 1. With the help of publicist Joe Hageman, McKiegan placed the Krells where masking tape outlined the spots usually occupied by my Wilson Audio WATT/Puppy 7s. The 1s were run biwired throughout the review period. Aside from some toe-out adjustment, that's where the speakers remained. What could be simpler?

Sound
I didn't move the twin towers of the Resolution 1s from their initial placements because they sounded right just where they were. I can't recall being put so quickly at my ease by a new pair of speakers in my system as I was when I first fired up the 1s—despite their presentation being very different from that of the mesmerizing mbl 101Es.

The Resolution 1s produced an immense and particularly lofty soundstage with a palpable and equally impressive phantom center image. The aural picture was dense and three-dimensional without being thick or sluggish. Stage depth was particularly well developed. Despite their size and complexity, the 1s "disappeared" immediately, neither giving away their physical positions nor creating a stage in which the sound bunched up when instruments had been mixed close to baffle locations. Because of all of these factors, it was easy to just sit back, relax, listen to music, and never sense that I could discern sound coming from any driver in particular, or the speaker overall. That's how it's supposed to be but often isn't—at least not without a great deal of moving and shifting. With the Resolution 1s, right from the start, I settled in comfortably and began to enjoy the music.

Given their driver array and size, I was taken by surprise by the ease with which the Resolution 1s settled in and made music without calling attention to themselves. I was expecting to have to work to get the drivers to integrate and produce a seamless, tonally pleasing presentation in my room.

My second reaction was to brand the Resolution 1 "old-fashioned," in the best sense of the phrase. The race toward ultra-high resolution by many speaker makers has come at the expense of dynamic range and bottom-end weight and authority. In some ways, the Resolution 1s reminded me of the refrigerator-sized, 1950s-vintage Jensen Tri-Plex corner speaker I picked up at a garage sale for $35 a few years ago. The thing kicks ass in ways most of today's "girlie-men" speakers simply can't. Of course, the Jensen 'fridge can't resolve information or respond as quickly as can a modern speaker like the Resolution 1, and if I had a pair of them I doubt they'd image worth a damn. But once you hear something with that kind of sheer physicality, authority, and slam, you want all that added to the modern mix.

I'm not claiming that the Resolution 1 brought back a sonic quality long out of fashion, only that the big Krell had what many of the speakers I've auditioned this year didn't, in terms of both slam and an ideal balance of lower-midbass warmth and fullness—and not at the expense of clarity or rhythmic suppleness. With a sensitivity of 90dB, the Resolution 1 should be reasonably easy to drive, depending of course on the impedance curve and electrical phase angle.

For reasons I can't explain, the Resolution 1 was not shy about producing prodigious bass. It was almost as if the physical properties of my room had changed, which they hadn't. When I played bass-test LPs such as The Clash's London Calling (CBS Clash3), or Davey Spillane's Atlantic Bridge (Tara 3019), or any of the others so often mentioned in my reviews, bass was deep, powerful, rhythmically supple, and tonally convincing—but mostly, it was intensely physical. The Resolution 1 gave up some tautness and speed on bottom compared to some other speakers I've heard of late, delivering instead impressive punch, weight, and richness, at the slight expense of nimbleness.

The bottom-end extension and balance yielded an enormous sense of physical space on live venue recordings, yet intimately recorded male voices—such as Johnny Hartman's on Speakers Corner's outstanding if somewhat mellow reissue of John Coltrane and Johnny Hartman (Impulse! AS-40), and S&P's superb new reissue of Nat King Cole's Just One of Those Things (S&P508)—were free of annoying low-frequency overhang or boom. Female voices were equally convincing—free of testosterone chestiness, while possessing sufficient body and weight to be believable. A nice balancing act!

Above the bottom end was a rich, coherent midrange with an emphasis on smoothness over resolution and transparency. On top, the familiar Vifa ring-radiator tweeter produced yet more smoothness, though at the expense of the sparkle and air available from, for instance, the Dynaudio Esotar tweeter.

Overall, the Krell Resolution 1's balance was on the warm, mellow, smooth side, designer D'Agostino evidently having been willing to give up some transparency, air, and detail in favor of smoothness in the mids and weight and authority on bottom. If chasing reverberant trails is your hobby, the Resolution 1 might not be to your taste. But if instrumental body, slam, and palpable three-dimensionality suit you, the Krell delivered them convincingly.

I spent a great deal of time comparing two vinyl editions of János Starker's renowned performances of Bach's Suites for Solo Cello: Mercury Golden Imports and Speakers Corner's new set, cut from the original tapes by Willem Makkee at Universal's Berliner mastering facility in Hanover, Germany. Both sound really fine, the new set having a richer, more mellow tone that emphasizes the body of the instrument over the bow strokes. Either one will make you weep, but the new reissue's richness produced a more convincing and physical cello tone. The Resolution 1s did an outstanding job of placing Starker in space, convincingly sized and well behind the front baffles, to the right of center. The sensation of the smallish space in which he played was subtly evident, as I'm sure engineer Robert Fine intended when he recorded this set in 1966.