Signature SE/R First Impressions & Build Quality

Besides RBH Sound's solid product line offering, we have found them to be one class act to deal with both professionally and socially. Over the years we have received rave feedback from our readers whom have purchased RBH product through authorized dealers. We have noted they are some of the most loyal customers not just because of their excellent sound quality, but because RBH Sound stands behind their products, and they sell though a network of well-trained dealers who are fully qualified to do the highest caliber home theater systems in the industry.

RBH Sound's Signature Series represents their "cream of the crop" in loudspeaker design. You may recall my personal reference system used the Signature T-2P System ; and to this date I still use their Status Acoustics Decimo as my reference bookshelf speaker. I was so enamored with this product that I pleaded with RBH to offer Status Acoustics driver upgrades to compatible products in their Signature lineup and sure enough they did!

Back in 2002 I reviewed the Signature 61-SE two-way bookshelf speaker system. Shortly afterwards I had RBH send me the Status Acoustic driver and crossover upgrades to do a comparison. The upgraded speakers were called the Signature 61-LSE (as in limited) and for a short time were sold to the public until they discontinued offering this upgrade. The 61-LSE offered about 90% of the performance of the venerable Status Acoustics Decimos, but at less than ½ the cost. It was an audiophile's dream come true, and brought this level of performance to a larger audience.

Now RBH is back at it with SE/R version of their Signature Series products (limited to products with 6.5" midranges only such as 61-SE, 661-SE, 1266-SE). The difference between the LSE and SE/R is the latter contains the standard Signature crossover while the LSE had the Status Acoustics upgrades. Hey, I told you guys to get LSE when they were offered - nothing lasts forever. Don't sweat it though as you will see in this review SE/R is pretty darn close to the LSE series in performance and only an Audioholic with an excellent room and discerning ear will likely hear a difference in a Double Blind Test (DBT) between the two.

The build quality of RBH Signature products is truly superb. Their cabinets are made of 3/4" HDF (High Density Fiberboard) and are baffle braced and well-insulated with Dacron or acoustic foam. The picture to the right is of the Signature 661-SE I recently took during my RBH On the Spot Location Tour last summer. As you can see, this is a very rigid cabinet. This is a MTM or D'Appolito driver configuration featuring dual 6.5" aluminum cone woofers and a 1" fabric dome tweeter. RBH's aluminum drivers are proprietary and are some of the best drivers on the market that we've tested. Their crossover networks feature air core inductors and polypropylene capacitors (you won' t find series electrolytic caps - even on their least expensive models).

There are several good reasons why RBH aluminum midranges and bass drivers excel in performance. These include careful engineering, and quality control. Granted, many manufacturers use aluminum drivers these days, but all are NOT created equal. Without the proper damping (both in the cone and the surround), cone shape, motor structure, and tight manufacturing tolerances, these types of drivers can be worse off than conventional paper cones. Because RBH Sound uses voice coil formers manufactured from Kapton, possess a superior ability to handle heat under even the most demanding conditions which minimizes power compression and distortion. The aluminum cone material is coated with a silicon-based material and the surround is made from butyl rubber to minimize ringing and resonance. The cone enters break up mode at a frequency well above the system crossover point and because of the measures RBH has taken to ensure a linear performance, it can operate higher than most conventional cone drivers allowing for a more acoustically seamless blend with the tweeter.

All of the speakers in this package (except the 44-SE's) were upgraded to the Status Acoustics phase plug version of their Signature 6.5" driver as well as the venerable ScanSpeak 9500 tweeter (which is arguably one of the best tweeters ScanSpeak has made to date).

Hi quality aluminum cone midrange driver with phase plug . Using aluminum for the cone provides benefits such as superior stiffness to weight ratio when compared with a variety of other commonly used materials. The driver operates in piston mode to relatively higher frequencies, minimizing break up distortion and dynamic compression due to cone flexing. The phase plug essentially eliminates the need for a dust cap, which in turn, reduces cone mass, permitting extended frequency response. It allows more airflow through the motor structure, which improves cooling and thus increases power handling. A Phase plug also helps to reduce on-axis beaming by dispersing higher frequencies that the cone is producing.

Note : Beware, many loudspeaker manufacturers use a quasi phase plug which looks like a phase plug for marketing purposes, but does not physically separate from the cone of the driver. These "so called" phase plugs can do more harm than good as they provide an inconsistent surface area and they also increase mass of the cone yielding poorer frequency response and linearity.

While the standard tweeter RBH uses in their Signature product (Vifa D27 series) is no slouch, I simply love the ScanSpeak upgrade. The ScanSpeak tweeter has higher power handling, lower resonant frequency (550Hz as opposed to 1kHz of the Vifa), and better off axis response. This yields a smoother, more open and airy sound quality with less compression. Because of a longer rear chamber, the ScanSpeak driver can play much lower than pretty much any 1" dome tweeter on the market. This takes the stress off of a midrange driver to produce frequencies it really can' t do effectively.

The disadvantage of this tweeter is a slight reduction in efficiency and on axis high frequency response. Thus the loudspeaker designer must reduce the overall system efficiency to compensate causing the end user to expend more power from their amplifiers to achieve similar loudness levels of the more efficient Vifa design. Is it worth it? Yes, if you have a discerning ear, quality electronics, good room acoustics and a slightly fatter wallet. The ScanSpeak driver is nearly 3x the cost of the Vifa, thus one of the reasons for the moderate price differential between Signature and Signature SE/R upgraded loudspeakers.

High Quality crossovers

Note : Beware, many loudspeaker companies use cheap electrolytic capacitors in series with the mid and tweeter drivers. Electrolytic capacitors are not very linear at high frequencies and thus should usually never be utilized in series for these crossover sections.