Klipsch Reference RB-75
My friend Gene is a professional musician. Back in the early '80s, he used Klipsch Heresys as PA speakers in clubs. One hot August afternoon, I dropped by his Greenwich Village apartment. Just for fun, he set up the Heresys at home. Hot damn, I was absolutely floored! The first LP (remember, this was in the pre-digital era) he played was the Rolling Stones' Exile on Main Street. Oh man, I thought I knew that record inside out, but not like that—the Klipschs sounded like a mini version of a concert system. We listened at extremely high levels, easily 100-plus decibels. Gene's neighbors must have thought Mick and the boys were gigging in his apartment.
Fast-forward to the present and Klipsch's new Reference RB-75 system. Guess which disc I popped in my player to get reacquainted with the sound? Granted, A/B comparisons separated by 20-something years are hardly fair, but Keith Richards' snarling guitar and Charlie Watts' cracking snare drum instantly yanked me back into the Klipsch zone. I've listened to Exile dozens of times over the intervening years, but no system has ever matched the Klipsch systems' nuance and shading. Cymbals, in particular, benefited from the horn tweeters' agility; they were remarkably vivid and present. Oh, and Jagger's vocals all but leaped out of the horns. Klipsch's stock in trade is dynamics—sudden loudness shifts are unleashed with an ease that more-conventional direct-radiating designs rarely muster. A by-product of that dynamic freedom is the ability to render the subtlest forms of musical expression. With two RB-75s rolling out the Stones' tunes, the line between home audio and the real thing was a lot smaller.
My review system included the new high-performance RB-75 bookshelf model ($1,200/pair), the RC-7 center-channel speaker ($800), the RS-7 surround speaker ($900/pair), and the RSW-15 subwoofer ($1,800). The system had the uncanny ability to put me in a good mood. Methinks that had something to do with those horn-loaded tweeters. The RB-75 and RC-7's deep-throated horns couple to compression-loaded 1.75-inch titanium tweeters. What does "compression-loaded" mean? Glad you asked. In a typical consumer horn design, a flared horn sits in front of a conventional dome tweeter (often referred to as a waveguide). Klipsch's compression-loaded tweeter fires into a small cavity behind the horn's throat. This technique uses the driver's output to compress the air in the cavity, which increases efficiency and lowers some forms of distortion. These drivers are built along the lines of professional sound-reinforcement drivers, and, sure 'nuff, the Reference models boast extraordinarily high sensitivity numbers: 97 to 98 dB per 1 watt. That's nearly 10 times more efficient than the average speaker; hook up these babies to a moderately powered (50 watts or less) receiver, and you'll still achieve massive dynamics and high levels without strain. Oh, and don't worry: If your ears can stand it, the Reference speakers can handle gobs of power. They easily accommodated my 350-watt Krell power amps. The point is, they're not at all fussy about electronics.
The RB-75, RC-7, and RS-7 use an 8-inch-square Tractrix horn that projects a controlled, 90-degree-horizontal by 60-degree-vertical dispersion pattern and significantly reduces floor and ceiling reflections compared with a conventional direct-radiating speaker. Those pesky bounces have a bad habit of smearing imaging. Great, so why are compression-loaded drivers so rarely used? I can think of two reasons: One, compression technology is expensive. Two, some speaker buyers are wary of a horn's cupped-hand coloration. I didn't hear anything so overt from the Reference speakers, but their soundstaging isn't as open and deep as that of the best direct-radiating speakers. Ah, but some of that open quality is an artifact of direct-radiating speakers' greater dispersion and more-prominent room reflections. I never detected any overt imaging hot spots from the RC-7's horn tweeter. When I moved side to side on my couch, dialogue remained tonally neutral, although the sound changed a bit when I stood up. Let's just say that horn speakers don't sound like direct-radiating speakers—you really must listen for yourself.
The RB-75 bookshelf model is brand new. Essentially, it's a scaled-down version of Klipsch's flagship tower, the RF-7. The RB-75 uses the larger speaker's 8-inch Tractrix horn and an 8-inch copper-colored diaphragm (it's actually Cerametallic anodized aluminum). The RC-7 center relies on a nearly identical 8-inch horn and 1.75-inch tweeter, along with a pair of those nifty 8-inch woofers. The Reference theme is carried over to the wedge-shaped RS-7 surround speaker, where those now-familiar 8-inch horns (with 1-inch tweeters) flank an 8-inch woofer. The RS-7's bipole/monopole array affords unusually flexible placement options. I like bipole surrounds; however, if you prefer the more-direct approach, substitute a pair of RB-75s for the RS-7s.
Klipsch has molded the RB-75's Tractrix horn into the speaker's front baffle to lower diffraction effects and create a cleaner look. In case you were wondering, all of the Reference speakers are ported designs. The RB-75 and RC-7 feature biwire connections, but the RS-7 has just a lone pair of binding posts. Speaking of wire, Monster Cable supplied the Reference speakers' internal wiring.
Even a cursory glance at the RSW-15 subwoofer's front and rear 15-inch drivers will leave no doubt about their mission. The front 15-incher is a passive radiator; the active rear 15-incher features a 3-inch voice coil and 30-pound motor assembly. It gets its marching orders directly from a 650-watt discrete MOSFET amplifier. The amp utilizes BASH technology, built to Klipsch's spec. Regarding the power rating, make note that it's 650 FTC watts continuous, 2,400 watts peak (few subwoofer amps meet the stringent FTC rating). The continuously variable low-pass crossover is adjustable from 40 to 120 hertz. Stereo line-level RCA inputs and outputs hug the lower rear panel, but the side-mounted volume-control knob is nice and handy. The enable/disable switch bypasses the sub's crossover.
Klipsch crafts the Reference speakers' impeccable maple, jet ash, and cherry real-wood veneers in their Hope, Arkansas, factory (the RS-7 is only available in a black or white vinyl finish). The magnetically attached grilles add a touch of gee-whiz cool.
I used the speakers with my Denon DVD-2900 player, Sunfire Theater Grand III pre/pro, and B&K AV6125 power amplifier; the cabling was all Harmonic Technology. The Reference speakers are fairly full-range designs, so I was tempted to run them wide open, setting the pre/pro for large speakers. That worked quite well, but I eventually switched to the small setting, crossing the speakers over at 50 Hz (the sound was slightly cleaner at very high levels). In either case, their blend with the RSW-15 sub was seamless. Tonal balance, even with the RB-75s on stands a good 3 feet out into the room, was slightly warm, and I prefer that.
I must apologize to all of my 11th-floor neighbors (and the folks on 10 and 12)—but hey, I had to explore the Reference system's effortless dynamics with full-tilt sessions. Listening fatigue remained low (for me at least). Even when I eased the volume to a more-sedate level, the speakers didn't turn blah. Cruising through the Miles Davis at the Blackhawk 1961 concert recordings, the music still felt very much alive. Norah Jones' exquisite Come Away With Me SACD had me swooning at 2:00 a.m. Unlike a lot of speakers that only give their best within a fairly restricted loudness range, this system had the rare ability to sound great at low, moderate, and high levels. I guess its purity/low-distortion sound has something to do with that. At this point, I temporarily substituted an Onkyo TX-SR501 65-watt-per-channel receiver for the Sunfire/B&K duo to see how the Klipschs sounded with an entry-level receiver. No problem. The Reference ensemble still packed a wallop. The absence of harshness was remarkable.
Spike Lee's 25th Hour is a moody film, and Terence Blanchard's ravishing score supplies heavyweight emotional underpinnings. The Reference system was just coasting along until the dance-club scenes. That space's atmosphere was fully realized, thanks in large part to the way the mighty RSW-15 pressurized my large theater; it throbbed with seriously down-low beats. The RC-7 center speaker rendered full-bodied dialogue, yet it was fast, fluid, and stunningly articulate.
Next, I cued up the World War II submarine drama U-571. Oh boy, the RSW-15's downright-menacing low-end fury filled my large room. Those famous depth-charge impacts set off motion detectors in my neighbor's apartment.
The new Led Zeppelin DVD was a special treat. I've waited for this music for decades, so please excuse me but the critical-judgment part of my brain shut down as soon as I fired up "I Can't Quit You Baby." I just sat there with a big, stupid grin, soaking up the band's brilliance at the peak of their powers. The sound was ear delicious!
What it all adds up to is this: The Klipsch Reference RB-75 system doesn't just communicate the sound; it unearths music and films' underlying emotionality. I didn't want to send it back.
• Thanks to the Klipschs' high efficiency, low-powered receivers sound extra gutsy
• Luscious veneers
RB-75 Bookshelf Speaker $1,200/pair
RC-7 Center-Channel Speaker $800
RS-7 Surround Speaker $900/pair
RSW-15 Subwoofer $1,800