Sugg. Retail: $1240 (CAN) pr
Size: 17″H x 9″W x 12 1/2″D
Manufacturer: Klipsch LLC
8900 Keystone Crossing
Suite 1220, Indianapolis, IN 46240 USA
(Reprinted from the Almanac 2001 Audio Ideas Guide)
The baby of the Klipsch Reference series, the RB-5 is a quite compact bookshelf model that uses an 8″ aluminum-coned woofer with Tractrix-horn-loaded titanium tweeter crossed over at 1950 Hz in a rear-ported enclosure. The cabinet is made of MDF, and comes in various wood veneers: mahogany, medium oak, and black oak. The review pair was in the mahogany, and a very nice finish it was, with a subtle sheen that can be seen in the photo above.
I don’t usually get into specifications with speakers except as confirmed by measurements, but one particular number is always relevant with Klipsch loud-speakers: sensitivity. Here that number is 96 dB, a figure probably unrivalled by any other compact speaker system. This is possibly the speaker for the single-ended-tube fan with a small room.
And looking at the measurements, we can see that the RB-5 is an extremely accurate speaker, something quite uncommon among very efficient reproducers. The Pink Noise Sweep (PNS) at top is +1/-2 dB across most of the range, that 2 dB largely reflected as a midrange dip. Its bass is quite extended, 10 dB down at 40 Hz, and 14 dB down at 30; careful placement to maximize the rear port output should result in surprising extension for the box size, as with the Energy v.2.2.
Even the quasi-anechoic curve below the PNS/SAR pair is within a 2-dB tolerance, unusual with any speaker. In the axial measurement below this, we can see that the 0 and 15o curves, are very smooth, with a midrange dip increasing at 30o, and the controlled horn dispersion reducing output at 60o off axis. The sum of these curves, the SAR, overlays the PNS at top, and tracks it very well, an indication of excellent driver matching and overall acoustic design.
The impedance curve shows woofer and port peaks, the latter at 50 ohms, a low point between them of 5 ohms, with a high of 29 ohms in the midrange. Maybe this speaker isn’t quite the answer for single-ended fans after all, since frequency response will tend to track the impedance curve with these amps in such circumstances. The midrange phase angle is fairly steep at +/- 45o, but we must remember that this is electrical phase, and that the horn loading of the tweeter, which puts it well behind the woofer, may well tend to bring it into better acoustic phase with it. The RB-5 should be fairly easy to drive, but a single-ended amp might not like the phase angle, either.
Though it tended to be just a little forward in its presentation, the RB-5 showed very good depth and overall spatiality. Its bass was tight and fast, with just a hint of deep bass in our listening position that could be enhanced in a bookshelf or close to corners. The sound was very natural and sweet on strings, with just a bit of extra bite in the upper midrange, especially on axis (seen in the quasi-anechoic curve at 6 kHz), but this disappears when the speakers are not angled in at the listener, which I do not recommend. Face them straight ahead.
However, there is no tendency to sibilance on voices, and a nice, open choral sound could be heard from the RB-5s. Dynamics were excellent for a small speaker, the effect of the extreme efficiency heard in excellent micro-dynamics, and an overall lively quality. I found no listening fatigue with the RB- 5s, their natural presentation and lack of distortion even at high levels real virtues. There is a slight horn coloration, but emphasis is on the word “slight”, since after a while you simply don’t notice any more, and just listen to the music. I found this to also be the case when listening to the Avant Garde Uno reviewed for Stereophile and now owned by friend and colleague Robert Deutsch.
The final thought about the Klipsch Reference RB-5 is its surprising amount of detail and resolution for a speaker under $1500. This is a monitor-quality speaker, and I suggest anyone looking for such a compact reproducer carefully audition it. With a good subwoofer (or two, as we tried it), it’s killer, sounding very much like a really big speaker system. It comes closer than it should to the Veritas in sound quality for its price. Have a listen to this gem from Klipsch.