- Written by Brian Florian
- Published on 06 December 2011
Paradigm Shift A2 Powered Bookshelf Speakers - Breaking it down
At first glance the A2seems little more than the proverbial 2-way, 5 ¼ incher. The name Active Atom suggests that it would be an Atom Series 7 with an amp bolted to the back, yet while they are cut from the same cloth, the design is unique enough that it might have been named differently. The tweeter is indeed the same 1" aluminum dome set in a critically flared baffle (a sort of quasi-horn) with a unique dot of fabric covering the center of the protective steel mesh, both of which are said to shape and optimize the dispersion characteristics. The mid/bass driver looks to be the same aluminum cone as the ones in the passive Monitor Series 7s, but it features a longer voice coil and larger magnet, primarily to address the fact that these are sealed alignment speakers as oppose to the ported design Paradigm usually favours. The cabinet is of course the very solid MDF construction we have come to expect with Paradigm, our review sample being wrapped in the ubiquitous vinyl black wood grain. Several gloss color coatings are also available at a price premium including red, white, grey, and black. A plastic frame cloth grill is supplied and is held in place by magnets, not snaps. These thankfully obscure at least partially the blue power light which is much too bright otherwise for my taste. Rubber half-sphere feet are provided and a desktop stand is available as a separate option which angles them up just a bit.
For connectivity Paradigm has come up with a fairly unique "daisy chain" topology. Rather than splitting the output of your source to two speakers, or feeding it to one of a dedicated left/right pair as is more common, the A2s are androgynous: the stereo signal is feed to one of the speakers (doesn't matter which one) and is passed along in its entirety to the second. It is a switch on each unit which determines whether it voices the left or right signal, or even a mix (so you could daisy chain 3 and have a quasi-center channel). While both 3.5mm and dual-RCA connections are given for both input and output, only one type can be used at a time (i.e. the two types are not bridged). At the top of the back plate is a gain control which feels solid but I wish there was some sort of gradation or detents to it so as to make matching gain level on the pair a little easier. Under it is a 120v ground-less receptacle, the intention being to power something like an Apple AirPort Express. A receptacle for the detachable power cord and a power switch round out the back panel. The units feature an auto-on/off not unlike what is common in powered subwoofers: after about 20 minutes of no signal they go into standby and as soon as signal is detected they turn on. The back panel boasts "Designed by Paradigm Electronics" which is to say that the A2s are among the growing number of Paradigm SKUs not manufactured in Canada.
So we've talked about the front and back, but inside is where the juice is at. Paradigm employs a 2-channel class D amp in each speaker, one channel for the tweeter and the other for the woofer, with 50 watts available between them. Bi-amped powered speakers usually have asymmetrical amp power, more for the woofer, less for the tweeter, but in this instance the topology of Paradigm's amp is such that the it can divert more (or less) of its total available power to either of its two channels (so as an example it could at a given moment deliver 40 watts to the woofer and 10 to the tweeter). Paradigm quotes a "dynamic" power rating of 100 watts total between the two drivers which is to say that momentarily it can dump as much current but in our opinion this is far less meaningful a figure. The analogue input is converted to digital at a 24bit depth and DSP (digital signal processing) applied with between 48 and 76 bit precision, at both the system level and separate tweeter/woofer level. Beyond the requisite high and low passes, Paradigm is principally using sundry DRC (dynamic range control) algorithms to reduce distortion at higher output levels. We are told that the woofer in particular gets a proprietary dual band DRC which extends the low end at modest output and limits it at high output so that it remains clean, albeit compressed, which although a sacrilege to hardened purists, is I suppose better (and safer) than a cone flying across the room. Paradigm's intention here is quite literally to make the most of the modest power available in a way which never allows it to sound "broken". We'll see how all this plays out in the listening.