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Reference 3A MM deCapo-i

The 3A Midi Master was a relatively successful speaker from the 1980s and was a forerunner of today's Reference 3A series of higher performance monitor speakers. The MM deCapo speaker has been around the audiophile community for a few years but only recently upgraded to the "i" for improved status.

The 3A Midi Master was a relatively successful speaker from the 1980s and was a forerunner of today’s Reference 3A series of higher performance monitor speakers. The MM deCapo speaker has been around the audiophile community for a few years but only recently upgraded to the “i” for improved status.
Product PointsApplications: Studio

Features: Two-way; 8.25-inch shaped cone woofer; 1-inch cloth tweeter; phase plug

Price: $2,500 per pair

Contact: Reference 3A at 519-749-1565, Web Site.

When the potentially harmful effects of crossover components are removed from a speaker the results can be very appealing, as is the case with the MM deCapo-i from Reference 3A ($2,500 per pair). I call it almost a one-way because the 8.25-inch main driver is almost full range and rolls off naturally at the rate of 6 dB per octave without any help from crossover components. This is a good thing as the amplifier is directly coupled to the main driver’s voice coil with consequential benefits not the least of which are efficiency (92 dB, 1watt at 1M), good LF control and an easy-to-drive smooth 8 ohm impedance.

As the main driver is rolling off (naturally), a single audiophile grade capacitor is rolling in a one-inch textile tweeter at the same gentle rate of 6 dB per octave. Could this be called a 1 1/2-way speaker? The beauty of this design is that the critical upper mid range is not corrupted by multiple filters trying to get drivers out of each other’s way spectrum wise.

The main driver is made from woven carbon fiber and has what the company calls a Hyper-exponential-shaped cone with a Precisely-shaped phase plug. This combination accounts for the more extended smooth high frequencies comparatively free from the usual peaks and nonlinearity found in most drivers this size.

A resonance absorbing Vibra-Puck disc is mounted on the back of the driver reducing superfluous frame vibrations. This custom-built wide range driver has been refined and tweaked over the years and is now considered by some audiophiles to be the heart of the best small monitor out there.

A one-inch soft dome tweeter was selected to match the main driver acoustically and electrically for seamless integration with a resonant frequency of 600 Hz, octaves below where the tweeter actually becomes active.

The enclosure has a rear tuned port and a slanted front baffle with the tweeters mounted to outside above the main driver so that left and right are mirror images of one another. The company recommends NOT toeing in the speakers but pointing them straight into the room thereby creating a slight HF delay with the tweeter distance to listener being greater than the main driver, bringing booth drivers into phase and time alignment. The cabinet is heavily braced internally making it extremely rigid and is finished in a beautiful high gloss piano black finish. All edges are attractively beveled minimizing diffraction. Two sets of five-way binding posts are mounted on a thick metal rear plate, accommodating bare ended spaded or banana connectors. Biwiring is highly recommended by the company although the de Capo-is are delivered with solid copper plate jumpers for single wire speaker cables.

Because of the efficiency of these speakers and the easy-to-drive load impedance, relatively small amplifiers can be used. I find that amplifiers with only a pair of output devices often times sound better than more powerful amps with lots of output transistors in parallel.

In Use

I set up the pair of deCapo-is on RPG speaker stands, toed in as I typically listen to and review speakers of this size. First impression was too much energy in the upper mid-range, but then remembered no tow. After pointing them straight into the room the upper mids settled in nicely with the rest of the spectrum and the tonal balance was significantly improved. Listening to what seemed to be off axis was a bit weird for me but there was no doubt that from top to bottom the amplitude response was very smooth and uncolored. The lack of crossover in the lower high frequencies gave the presentation a sense of clarity and realism not typical of any speaker I’ve heard. Brass instruments, especially trumpets and trombones benefited from this crossover-less design.

The bass was full and deep extending down to an honest 40 Hz. Using a quality amplifier with good low frequency control and high damping factor like the Bel Canto eVo presents a bottom end experience hard to beat in a speaker this size. I’m sure some of this is due to the fact that the amplifier is directly coupled to the drivers voice coil and not a series inductor which is typical of most crossed-over speakers.

As long as I sat in the sweet spot equidistant from each speaker the deCapo-is sounded great, but as soon as you move from one side to the other, the tonal balance changes and the closer speaker exhibits a boost in the upper midrange which could be a problem for monitoring with a large console. But with today’s workstations this should be no problem at all.

(Editor’s note: Reference 3A says it now offers a ‘Studio’ version with more tonal balance and better behavior with solid state amplifiers.)


If crossovers get in the way between you and the music, you should definitely check out the Reference 3A deCapo-is. The clarity in the upper midrange is exceptional. Extended articulate bass, smooth natural mids, open and airy highs make the deCapo-is a real contender for high-quality monitoring.