MC-6C Speaker Build Quality & Design Overview

Introduction

One of my first introductions to RBH Sound was when I took a leap of faith and ordered their TS-10A subwoofer. This was before Audioholics existed and I was just breaking into the audio scene. Prior to getting the TS-10A, I never experienced a really good sounding sub and the others I demoed in my home simply didn’t do it for me. I recall the thrill the TS-10A gave me NOT solely because of its ability to belt out LOUD SPL, but because of its musicality in doing it. Shortly after, I had RBH send me a pair of their original MC-6C bookshelf speakers to evaluate. I hooked them into my system and gave them a listen. While I enjoyed their forward presentation while listening to percussion instruments, I felt they were lacking in upper extension and overall transparency. My reference speakers at the time walked all over them, so I sent them packing. It wasn’t until RBH Sound sent me a pair of their Status Acoustics Decimo’s that I truly became a believer in their speakers. To this day (nearly 7 years later), I still use them to judge all other bookshelf speakers against and so far, not one pair has been able to dethrone them.

RBH Sound’s chief engineer Shane Rich was unwilling to accept defeat. Never staying complacent, he was looking to improve the sound quality of these speakers and hence the Mark II version of these speakers was born. The MC-6C remains a two way sealed bookshelf design, just like its predecessor.  Gone however are the cheesy swivel dome tweeters of yesteryear, now replaced with a new 1” fixed aluminum dome waveguide tweeter on their new RDAB (Resonance Damping Alloy Baffle) baffle system. Sounds fancy huh? According to RBH, RDAB reduces cabinet resonance to improve sound quality, most notably in the critical midrange frequencies. Doing a knuckle test on the cabinet and baffle, it made a deadening thud demonstrating the cabinet was indeed very inert. Ok so at first glance, the new MC-6C appears to be quite an improvement over the original design. But, will the sound quality live up to my expectations of what an RBH speaker should sound like, or will I send this speaker packing like I did the last time I heard them? Read on to find out….

Build Quality

RBH Sound products have always received high marks from us in the build quality department. There is good reason for this. They don’t skimp on driver components or parts. The cabinets are constructed from ¾” MDF and are overstuffed with high quality Dacron insulation. The drivers are recessed into the MDF baffle as any good speaker should be. Then the RDAB baffle completely covers the driver baskets and screws adding a nice finishing touch to the aesthetics of the product. The grilles are framed with MDF instead of cheap plastic and utilize very attractive aluminum pegs that make for excellent contact with the cabinet. There are no discernable seams or edges in the cabinet's and they came finished in a beautiful black oak veneer are high quality textured veneers.

Unfortunately because of the molded baffle design, I was unable to pull the drivers out for some real photo ops. I did manage to take the back speaker terminal plate off to examine the crossover and heavy cabinet insulation and requested a picture of the woofer driver from RBH Sound to use in this review. Should this speaker ever require servicing, RBH would likely have to simply replace it as it cannot easily be taken apart. With a 5 year warranty from a highly reputable company, I don’t foresee this as being a major issue.

The Woofer

The 6 ½” aluminium cone woofer is very similar to the driver used in their Signature Series except the basket is stamped rather than cast aluminum. While this is certainly a design compromise over a good ole cast basket, it’s an understandable one. Let’s not also forget so many speakers from other brands exclusively use stamped baskets on even their most elaborate designs. RBH Sound still employed many of their tricks from their Signature line woofers including bumped backplate on the magnets, polyimide film voice coil formers for higher power handling, silicone coated aluminum cones and butyl rubber surrounds to minimize resonance and ringing. Also note this driver is fully shielded and the magnet structure is encased in a metal can to reduce any stray fields. Many manufacturers tend to skimp here and only provide the opposing magnet without the metal can.

Tweeter

The 1” aluminum dome tweeter employed in the MC line is a completely new tweeter for RBH Sound. The driver utilizes a waveguide to control dispersion for optimal off axis response, and has a rubber surround to allow for longer excursions so it can play lower in frequency for better integration with the woofer driver.

Crossover

As usual, RBH doesn’t skimp here like so many other manufacturers do. You won’t find any cheap electrolytic caps in series with the tweeter. Instead you will find audiophile polypropylene capacitors, ceramic resistors and air core inductors.

The speaker design relies on the electrical crossover network and natural acoustical roll off of the drivers which the overall response can be best described as a 2^nd order Linkwitz-Riley design which produces a -6 dB crossover point to achieve a maximally flat amplitude response.

The Backside

The MC-6C has a very clean back end. RBH employs a 5-way gold plated binding post utilizing indented terminal lugs. I am not the biggest fan of these binding posts since they can be quite challenging to turn on thick gauge wire as they are closely located. Personally, I use compression banana plug terminations so it becomes a moot point. The completely rounded cabinets look great at any angle but, of course, look sexiest from the front because of the shiny aluminum drivers and molded baffle.