RBH 641-SE loudspeaker
These days, RBH—so-called after the initials of its founder and president, Roger Hassing—makes and markets speakers under its own name. The company is a major player in the world of custom installation, with a wide range of in-wall speakers manufactured for them in China. They also offer home-theater systems. However, RBH hasn't forgotten its two-channel roots, and in their Utah plant they manufacture their Signature series, all of which feature metal-cone drive-units of RBH's design.
I took advantage of my visit to audition several RBH speakers in their listening room, using some of my own recordings. I was impressed enough by the slim, floorstanding, $1500/pair 641-SE to request a pair for review.
A trim-looking tower
The RBH 641-SE stands 39" tall, and conceptually consists of a minimonitor integrated with a bass section. It combines a Vifa 1" silk-dome tweeter with a small-diameter midrange unit, these placed at the top of the tower. The midrange unit covers a wide region, from 150Hz to 3kHz, and features an inverted aluminum dome terminated with a rubber half-roll surround. Frequencies in the upper-bass region and below are handled by a pair of 6.5" woofers mounted on the side of the cabinet. (Each pair of speakers is "handed"; ie, the woofers are mounted on opposite sides of the left and right speakers.) The woofers again use inverted metal-dome diaphragms, and are reflex-loaded with a large plastic port 3" in diameter and 5" deep on the rear of the cabinet. The speaker is so narrow that the woofer magnets almost reach the inside of the cabinet's opposite side wall.
Electrical connection is via two pairs of binding posts at the bottom of the cabinet rear. These have a nonstandard tri-lobed nut, but a suitable nut-driver is supplied. The crossover is hardwired, with components glued to the base of the cabinet. Mostly air-cored coils are used, though there is one large transformer-cored inductor, this presumably in the woofer circuit. Other than one plastic-film type, the capacitors are all nonpolarized electrolytics.
The upper-frequency drive-units are rabbeted to lie flush with the front baffle. The cabinet appears to be made of ¾" MDF and is lined with gray foam. The review samples were handsomely finished on all visible surfaces with zebrawood veneer. (Wood veneers add $300 to the per-pair price in basic black of $1499.) Because the tall, thin tower is rather unstable on carpeted floors, outrigger stabilizing feet are supplied, which screw into the base of the cabinet. These are fitted with rug-piercing spikes.
The RBH 641-SE's upper-range drivers can be covered by a small grille consisting of black cloth stretched over a bulky wooden frame. I left these grilles off for my auditioning. Each woofer is inset to allow it to be covered with a circular black grille; these I left on. I started out with the woofers on the outside edges of the speakers, but, dissatisfied with what was happening in the bass, I swapped things around so that each speaker's woofers were facing the other's.
I endlessly fiddled with the speaker positions, but could not eliminate a feeling that the lower-frequency integration was not optimal. There was sufficient midbass present, with extension apparent down to the 40Hz 1/3-octave band, but no matter what I did, the bass never seemed fully connected with the upper frequencies. I then had to replace the RBHes with the Thiel CS1.6es that I reviewed last month. When I set up the 641-SEs again, I had already looked at the measurements (see figs. 4 and 7 in the "Measurements" sidebar), so I tried inverting the electrical polarity of the woofers, using wire jumpers rather than the supplied shorting strips. This sounded better to my ears—Stanley Clarke's double bass on "Nevermind," from Stereophile Test CD 3, both had better upper-bass definition and was better integrated with the left-hand register of Herbie Hancock's piano—so I continued my auditioning with the speakers wired this way.