|RBH MC-615-70 In-ceiling Speakers|
|Home Theater Loudspeakers In-wall Loudspeakers|
|Written by Bryan Dailey|
|Monday, 01 August 2005|
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When building my home theater, one of my biggest dilemmas was where to put the surround speakers. My theater is located in a room where a sectional sofa runs the full length of the back and side walls, so stand-mounted surrounds were out. Wall-mounted surrounds were out, too, as only one wide wall is available for speakers. The answer was to go up and ceiling-mount the surrounds. For my application, I chose the MC-615-70 from Utah-based speaker manufacturer RBH. This $299 (each) in-ceiling speaker features a 6.5-inch aluminum woofer and a one-inch swivel aluminum dome tweeter. A tweeter level control, accessed from the front of the speaker, allows you to choose from a standard-level setting or from -3dB or +3dB. The MC-615-70 has a frequency response of 50Hz - 20kHz±3dB, is 88dB efficient and features a built-in 70-volt multi-tap transformer. These speakers are rated at 120 watts at eight ohms and have a crossover frequency of 3,000Hz. The paintable white grille covers give each speaker a finished dimension of 10 3/8 inches wide.
Because my master bathroom is located directly above the ceiling where my surround speakers were to go, I opted for the commercial spec MC-615-70 from RBH rather than the standard MC-615. The main difference between these speakers is that the MC-615-70 has a nine-inch metal enclosure over the back of the speaker that prevents some sound from going up into the air space above, but more importantly, it makes the speaker UL-listed fireproof. This not only has helped me to avoid transmitting sound vibrations to the tile floor in my bathroom above, but it also gives me peace of mind in knowing that I have UL-Listed speakers in my ceiling. The speaker is fairly tall with this enclosure attached, so you want to make sure you have adequate space above the drywall in your ceiling.
Installation was a little tougher than I had originally expected, but not because of any fault of the speaker. It turned out that the ceiling beams that run across the top of my theater room were spaced about a half-inch too close together for the speaker to fit in between them. After finding where each beam starts, using a stud finder and tracing the correct size circle using the included template, I realized that I was going to have to notch out one of the beams just a little bit for each speaker. For most applications, a simple drywall saw and a steady hand will do the trick, but I had to break out the jig saw and cut out a small section of the two beams. Thankfully, there are enough beams and I only had to take small pieces out, so there is no issue with the structural integrity of my ceiling. I then wired up my XLO Speaker wire that had been pre-run to these locations. A simple system of rotating brackets allows the speaker to be mounted in the ceiling and then the round grille cover is slid in to place. RBH also included an optional O-shaped bracket to be used with the MC-615-70 for drop ceilings to prevent the speaker from falling in case of fire or ceiling tile malfunction. Built-in seismic strap eyelets can accommodate seismic straps to meet building codes for commercial applications.
I paired these in ceiling speakers with RBH’s new on-wall speakers, the WM-24, which feature four four-inch aluminum drivers and a one-inch aluminum dome tweeter in the middle. For a center speaker, RBH’s MC-414C MK II was placed on a shelf just above my TV, about 20 inches in front of the back wall. The subwoofer in my system currently is Energy’s S8.3. My ceiling is nine feet tall and I was able to use my receiver to dial in the speaker’s volumes and delay settings with the speaker set-up menu, using a tape measure.