Audiophile Review!KEF R900 3-Way TowerMatched-Pair Loudspeakers“Impressive High-End Sound”

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Brevis
Price: $5,000 per pair

Likes: hi-end sound, KEF Uni-Q drivers
Dislikes: Not much 35-Hz bass

Wow Factor: looks as good as it sounds

More info: KEF R900

by John Gatski
  KEF has hit on a winning formula for its various lines of hi-fi loudspeakers. These designed-in-UK, manufactured-in-Asia transducers offer excellent sound quality. There are high-dollar  models, the ultra-modern looking KEF Blade for example but many of its lines are not that hi-end in price. In fact, the R900 tandem that I reviewed here are astonishingly good with a projected accuracy and air that rival speakers 2X the price, plus they kick out plenty of musical bass and look quite stylish.

Features

  Priced at $5,000 per pair, the R900 is a medium-sized tower, 3-way loudspeaker with KEF’s highly praised Uni-Q driver array. Drivers include 1-inch aluminum dome tweeter, 5-inch aluminum midrange and an 8-inch aluminum cone woofer. The vented tower (four rear ports) measures 44.5-inches tall, 9.4-inches wide and just over 14-inches deep. They weigh a manageable 65 pounds each. They come with a four -spike special mounting platform that the user has to install. The grill is magnetically attached.
  The speaker connections consist of two pairs of binding posts with a unique link knob that connects the drivers for uni-wiring, or separates them via the upper and lower posts for bi-wire. No jumpers to lose.

The KEF R900 speaker is a well-conceived, three-way tower that performs well above its price point. As a stereo pair, the speakers offers a balanced symmetry with airy highs, a very good midrange and ample low-end with nary any bloominess.

  Spec wise, KEF does a great job with their factory rated specs; the -3 dB, supplied measurements range from 40 Hz to 28 kHz (-6 dB is 37 Hz to 45 kHz). My own in-room response, using an analog RTA, revealed a 40 Hz to 20 kHz response, within 4 dB. And that is free standing, several feet from the back wall. Pretty good specs!

  The crossover points are 400 Hz for the midrange and 2.9 kHz for the tweeter/ The speaker can generate levels up to 115 dB and has a 90 dB sensitivity (ref: 2.83V/1meter). The R Series, as a whole, has trickle down technology from the KEF Blade. You can see and hear the lineage. 

The setup

  The KEF R900 arrived in easy-to-unbox packing boxes, and I had them out of the box and attached to their platforms in about 15 minutes. The speakers were placed about 8 feet from the listener position, slightly toed-in.
  Associated equipment used in this review included: a pair of Pass SR-2 towers, MartinLogan Montis electrostatics and a pair of Legacy Studio HD stand speakers. The R900 were powered by a variety of amps during the review including a Pass X350.8 with 350 wpc supersymmetry MOSFET output, Bryston 14B-SST with 600-WPC bipolar output, Rogue Audio Medusa digital/tube hybrid with 200-WPC, Coda’s new CSiB high-end integrated with 400-wpc bipolar output, and my trusty vintage Mcintosh MC-275 from 1965.

The R900 features bi-wire/link using two knobs

  Preamps included the discrete output of Oppo’s HA-1 DAC/HP preamp, Rogue Audio RP-5 tube pre, as well as my reference Coda high-current preamp. Sources included an Oppo BDP-105, Apple Macbook Pro with the Audirvana software player, an Android tablet with USB Audio Player Pro, and a Clear Audio Emotion turntable with Benz MC cartridge

  The players were also linked to a number of DACs,  including the Benchmark DAC2-DX, the aforementioned Oppo HA-1 and Mytek Manhattan. DSD and PCM audio were put through the DACs. All analog and digital cables, including the speaker cables, were from Wireworld. The power cords and strip were courtesy of Essential Sound Products.

  With the primary connection done, I angled the R900s inward slightly and took the grills off (I like to see my drivers in action as well). With regard to the four rear ports, located at the height of each driver group, I decided to insert the foam plugs into all the holes and then later listen with them out to see if there was a significant difference. (In my room, I did not detect any major difference with the plugs in.)

The audition

  First up was the Anthony Wilson Trio — Our Gang SACD, one of the most organic Jazz guitar/organ albums that I have heard in hi-res. The high-res, direct DSD recording also reveals abundant upper-end cymbal flourishes and that wonderful tube amp sound from the Hammond organ and the Gibson jazz guitar of Mr. Edwards.

  The KEF R900 related this high-res DSD jazz recording with the essential warmth and detail I am used to hearing from my high-end speakers. A nice, spacious soundstage with plenty of space between the instruments. The top-end was never hard or edgy; the aluminum-based mid-frequency driver delivered a quick, tonally correct midrange — without exaggeration or hollowness.

  The basss driver were equally impressive, with the metal drivers delivering good thump, but with quick precision. Since the organ‘s mid-bass chords are emphasized in this recording, I wanted to see if the port plugs made a difference in the midbass.

  In my room with the speakers in the middle of the room, I did not hear a significant change in the bass character. In fact, the plugs, did not make much difference, since the speakers were well away from side walls and back walls. The port plugs may come in handy with more problematic rooms.

  The balance of the R900s created a clean, immersive tone with lots of violin harmonics getting through. The violin’s upper-end energy was not hard sounding. It was, er, just right, to borrow a phrase.

  Next up was the Warren Bernhardt - So Real SACD, courtesy of Tom Jung’s excellent DMP recording label, circa early 2000. As I have said over and over in my reviews, this jazz recording of piano bass and drums, is one of the best ever made in terms of the real character of recorded music. The drum cymbals and piano tone are spot-on delicious.

  Like other top--notch speakers I have auditioned over the last 20 tears, I am pleased to say that the KEF R900 pair also does justice to this recording. The metal dome tweeter effectively radiates the top end of those wonderful cymbals, yet no stereotypical edgy or resonances. Bernhardt’s Steinway piano also passed the muster via the KEFs. That articulate upper-register tinkle — with its brilliantly captured depth — was delivered just fine.

  As with other premium tower loudspeakers reviewed in my listening room, I like the open imaging character, and tight, precise balance of the R900s. The speakers did not have as much room-filling presence as my MartinLogan Montis electrostatics, which radiate from both sides, but still, I liked the way the conventional-driver KEFs filled the room. The tight, but surprisingly deep musical bass for an 8-inch woofer, also helped solidify the positive quotient of this speaker. The speakers don't have that ultra low-end like some of the double driver,  tower  speakers I have listened to, but they are very good for music.

  Turning to ultra hi-res Classical music, I played the first movement of the Mozart Violin Concerto, a 2L 24/352 DXD recording, downloaded from the 2L site (Marianne Thorsen, violin; Trondheim Solistene Orchestra with Øyvind Gimse conducting). The track was played with USB Audio Player Pro, an ASUS Android tablet and the TEAC UD-503 DAC reviewed on EAN a few months ago.

  This recording is an excellent test for speakers to plumb the complex depths of the violin tone. The high-res recording system captured the performance, Can the audio playback gear transfer that recorded sound? Mated with the Coda Technologies CSiB, a superb 400-wpc integrated amp (with EAN review upcoming), the R900s produced the violin and accompanying orchestra with convincing authority. The balance of the R900s created a clean, immersive tone with lots of violin harmonics getting through. Reminds me of the excellent, metal-dome RBH-loudspeakers I have auditioned in the past. And as with the drum cymbals, the violin’s upper-end energy was not hard sounding. It was, er, just right, to borrow a phrase.

R900 comes in several finishes, including this brilliant white

  I also played a Classical violin and piano performance on vinyl through the KEF R900s: the Impex label reissue of the 1956 Jascha Heifetz/Emanuel Bay - Beethoven Sonata 8 and 10, originally recorded for RCA. This early mono tape recording has a natural openness and revealing detail as played from the master and his violin. Good speakers showcase the mono image of this recording with room-filling fullness and dimension. Not quite stereo, but very convincing nonetheless.

  As I expected, the R900’s projection of the two instruments ranks up there with other high-end tower speakers I have tried; the mid/tweeters’ tight accuracy dynamically captured the essential violin and piano tone. I was impressed by how much of the recording room’s ambiance could be detected via this mono mix.

  Switching over to Pop music, I played the HD Tracks 24/192 download of Michael Jackson — Off The Wall. Sonically (and, arguably, artistically as well) his best album. The amalgamation of Disco, Funk and Latin rhythm-infused music, combined with those catchy, hooked filled lyrics: this is analog recording at its best.

Living Off The Wall
 The KEFs were right at home with the thumping, but not overly bloomed bass lines, the out-in-front rhythm guitar and horns, and all the percussion. The hi-res transfer of the OTW multitrack never got lost coming out of the R900s, maintaining a listenable, articulate balance to all that sonic business. And again, the tweeters never sounded hard or edgy.

  For a vocal demo, I popped in the Celine Dion — Falling Into You CD and listened to her performance of Eric Carmen’s “All By Myself.” One of her best songs. Ms. Dion was at her prime in the mid 1990s, and she does such a great job with the vocal range of this song. From a gentle, just-above-a whisper to  her major vocal crescendos, the KEF R900s proved  themselves quite worthwhile on the vocal performance. They magnified Dion’s voice finesse, without excessive sibilance or being overly recessive, as some three-ways are.

Anatomy of an R900

  By the way, these speakers had no problem being driven by any of the amps I had on hand during the demo. As mentioned, the Coda CSiB, the Bryston 14B-SST bipolar, the Pass X350.8 MOSFET and the state-of-the-art digital tube hybrid Rogue Audio Medusa — they all matched with the R900s, with only the amp’s sonic variations revealing any audible differences. I did a lot of listening on the Rogue, Coda and Pass amps.

  Based on my R900 paring with the old Macintosh MC-275, the KEF's also are a good match with tube amps. Other than the slight bit of slowness in the mid/upper bass emanating from the Mac, the tone was smooth, detailed and seductive. Too bad, I did not have a tight bottom end tube amp to try with these speakers. Still, the old man Mac's mid and top-end were might good via the R900s.

The verdict

  The KEF R900 speaker is a well-conceived, three-way tower that performs well above its price point. As a stereo pair, the speakers offers a balanced symmetry with airy highs, a very good midrange and ample low-end with nary any bloominess. At the $5,000/pair price point, it lacks the deepest, under 30-Hz bass, but for most music, the low end is plenty. And the speakers work with most any amplifier, including the latest digital version — all the way back to old tube amps, like my old Mac MC275.

  If you are into a true, sonic picture of the source audio, especially hi-res music, the R900 is a speaker to consider. You need at least a medium-size room to enjoy its virtues. If you have the space, I have no doubt the KEFs will make you happy. The pair gets a Stellar Sound Award and a nomination to the 2016 Speaker of The Year list.

  John Gatski has been evaluating consumer, audiophile, home cinema and professional audio gear since 1988. In 1995, he created Pro Audio Review, and he has written for Audio, Laserviews, Enjoy The Music, The Audiophile Voice, High Performance Review, Radio World and TV Technology. Everything Audio Network is based in Kensington, Md. Articles on this site are the copyright of the ©Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited. John Gatski can be reached via everything.audio@verizon.net