Paradigm Reference Active/20 loudspeaker
By John Atkinson   •   November, 1997 There are many benefits accruing to a loudspeaker when its designer goes the active or powered route. The usual losses and distortions associated with passive crossovers can be circumvented, while the fact that the amplifiers and drive-units can be designed as a package enables the designer to squeeze more performance from each than would otherwise be the case. And the savings gained from the absence of a separate amplifier chassis can be passed on to the consumer.

Yet with the exception of some domestic models from Meridian, Genelec, and Mackie, and powered subwoofers from many home-theater manufacturers, active speakers have not caught on big with audiophiles. I suspect it's an issue of choice: buy an active speaker and you're denied the freedom to select an amplifier from a favorite manufacturer. And when you go active, your existing amplifier metamorphoses into a costly boat anchor.

Nevertheless, brave manufacturers continue to introduce powered speakers. I first heard the subject of this review, Paradigm's diminutive Reference Active/20, at the 1997 Winter Consumer Electronics Show, and was sufficiently impressed by what I heard to request a pair of review samples.

Going active
Minimonitor-sized, the two-way Active/20 features Paradigm's usual 1" aluminum-dome tweeter coupled to a mica polypropylene-cone woofer of nominal 6" size (the yellow, partially see-through cone is just over 5" in diameter). The woofer features an inverted-roll surround and is built on a diecast chassis. This has flanges to its side that mate with the substantial frame of the grille to give a smooth, obstruction-free acoustic environment for the drivers. The woofer is reflex-loaded with a large port on the speaker's rear. This port is 9" deep and 2" in diameter, and is flared on both ends to reduce turbulence at high levels.

Clues to the speaker's active nature are the green, LED-illuminated Paradigm logo under the woofer on the grille, and the large array of vertical heatsink fins on the top half of the rear panel. Three rotary controls beneath the heatsink control Level and High- and Low-Frequency Contour, while signal input is switchable between singled-ended (RCA) and balanced (XLR). Another switch engages a high-pass filter, for use with systems including a subwoofer.

The Active/20 can be set to be on all the time, or only when it detects a audio signal. I used the latter setting, as the time constant seems sensibly set. The speaker stays on long enough without signal that you have time to change a CD, or go to the kitchen for another beer. (Some active speakers turn off far too quickly, I have found.) The woofer is driven by a 110W amplifier, the tweeter by a 50W amplifier. While this power ratio may seem sensible on typical music program, my experience has been that, for wide-bandwidth signals, the tweeter needs to see as much voltage swing as the woofer. However, Paradigm may well have been sensible in setting the HF unit's power conservatively.

Let's rock
It took me a while to find the optimum place for the Paradigms in my room. Positioned where the PSB Stratus Gold is had performed so well for last month's review (October '97, p.199), the Active/20s produced too much upper bass, the balance sounding unacceptably thick. Suspecting a coincidence between the distance of the woofers from the wall behind them and from the floor with the speakers sitting on the 25" AudioStream stands, I moved the Paradigms out in stages; eventually they ended up about 45" from the wall. In this position, the upper-bass transition sounded smooth and even. I left the speakers in this position for the rest of the review period.

My first impressions were very positive. With the tone controls set to their center, detented positions, a laid-back mid-treble was coupled with a slightly mellow top octave, an uncolored midrange, and what sounded like an astonishing amount of bass for such a small speaker. True, it was really midbass, but the speaker appeared to give full measure down to 40Hz, with a useful amount of 32Hz audible. Below that, however, nada. The in-room output dropped like a stone, implying a high-order rolloff of some kind.

Low-frequency definition was okay. The speaker didn't boom, but neither was it the tight-as-a-nut, bottom-falling-out-of-your-world kind of bass that, say, the $15,000/pair EggelstonWorks Andra routinely serves up. But it was good enough that extreme levels of ultra-bass, like the ridiculous B-string thundering on Dread Zeppelin's 1991 5,000,000 (IRS X2 13092), caused my feets to start dancing.