Two-way bookshelf speakers using a 6.5” woofer and 1” dome tweeter are one of the most prevalent design types available. Any speaker manufacturer looking to release another speaker in this configuration is going to have to execute it seriously well if they want attention in this crowded market, especially in the sub $1k price range. This is the challenge Revel is attempting to surmount with their Concerta2 M16 bookshelf speakers. Although Revel has demonstrated top-notch engineering in the past, they still have their work cut out for them to stand out in a field of dozens– if not hundreds– of similar speakers. So what is Revel bringing to the table to make their bookshelf speakers noteworthy? Read on to find out…
The appearance of the M16 is clean and stylish, almost minimalist. The M16 comes in either white or black with a high-gloss finish. A waveguide on the tweeter is cut to form around the gasket of the woofer in a stylized gelling of the drivers, a nice design touch topped off with no visible screws holding in the drivers. Magnetic grilles do away with the need for visible fasteners on the front baffle which further assists its uncluttered appearance. Only a small logo interferes with these clean lines, but not intrusively. A removable logo with a magnetic hold would have been a neat detail. The front of the speaker is nice enough that it would be a shame to use the grille at all; the M16 looks better without the grille.
The curved sides of the cabinet towards the back are a welcome departure from a simple rectangular box endemic of so many bookshelf speakers. The visual simplicity and high-end gloss finish make the M16 a bookshelf speaker that enhances almost any home furnishings. It fits in perfectly with modern decor, especially with the available white finish, but wouldn’t clash at all with a more traditional interior design.
The M16 looks nice, but how well is it built? A simple knock on the exterior produces a dull thud that gives a sense of solidity, which is a positive attribute in a speaker. The 16 lbs. heft of the M16 also bodes well for the build quality, and although weight alone does not guarantee a good build quality, heaviness bodes well for a better build quality than a lightweight speaker. A stiff and heavy cabinet is needed in order to reduce resonances which can interfere with the sound that is only supposed to be created by the drivers and port. The cabinet exterior walls are ¾” MDF, and a ½” thick window brace is mounted between the tweeter and woofer sections of the cabinet. Revel’s literature on the M16 boasts of using the ‘Kerf Technique’ to bend the sidewalls using perpendicular slots instead of V-grooved joints, and a layer of fiberboard is used to reinforce the internal slotted wall of the cabinet. Stout five-way binding posts ensure a tight grip on the speaker wire, whether using banana plugs or bare wire tips. Altogether the cabinet construction of the M16 is sensible: robustly built and without the overkill construction of extreme high-end speakers which can often multiply the cost for negligible returns in performance.
The 1” aluminum dome tweeter uses a waveguide and an acoustic lens to match the directivity of the woofer in an effort to produce a seamless transition between them. This is in line with the philosophy of many of Harman’s speaker brands, of which Revel is one, that advocates for a uniform off-axis frequency response as well as on-axis response for the best overall soundstage and imaging. The idea behind this design decision is that much of what is normally heard in-room is not direct sound from the speakers to your ears but acoustic reflections off room surfaces and so the off-axis response becomes very important in accurate sound reproduction. The shape and curvature of the waveguide is critical and must be modeled very precisely to match the dispersion pattern of the woofer at the crossover frequency. The waveguide and acoustic lens of the M16 also raises the tweeter sensitivity, especially around the lower frequencies of the tweeter’s band. Boosting sensitivity in this frequency region is a big help, because it is where the tweeter is likely to generate the most distortion, since it is where the tweeter is the most stressed mechanically.
One innovation in the tweeter assembly itself is Revel’s inclusion of a larger than normal cavity behind the magnet assembly which is also vented. This lowers the tweeter’s mechanical resonance down to 800 Hz from the more typical 1,500 Hz, so there is not a trace of that resonance heard at all.