Already available in Australia, the US and some European companies, AktiMate's Mini is now distributed in the UK, and is described as “first and foremost a serious hi-fi loudspeaker”, enhanced by the addition of an iPod docking station and selling for around £330. An additional pair of RCA Phono outputs also allows connection ofa second AktiMate system for use in another room, or a subwoofer, and a video output can feed iPod material (eg display info) to a larger monitor. Features include an encoder type volume control on the powered speaker, and a compact remote control handset. Input impedance is10kohm, the toroid transformer is a generous 120VA, and each speaker is 185x300x210mm (wxhxd).
Attractively finished in piano lacquer ivory white, these tidy looking compact loudspeakers had neat, well fitted trim rings around the drivers and a modern grille-less appearance (except for a protective mesh over the tweeter). A small pair of field glasses could help read the intrinsically small display of an iPod when inserted in the left hand speaker dock, and the handset's firing angle is very narrow, so good aim is required to home in on the sensor window of the left speaker. This channel has all the electronics including stereo amplification, connecting to the wholly passive right hand speaker via an economical twin cable. One could point out the potential mismatch effects of one channel being passive and the other carrying all the electronics, with a consequently different internal volume and structure. One could also query the wisdom of supporting the iPod music source on a inherently vibrating top surface. While neither factor is exactly good audiophile practice, they seem acceptable enough compromises in view of the reasonable price.
The supplied soft foam rubber feet could support the speakers on a shelf or desk top, but these speakers have at least the potential for true hi-fi performance and therefore deserve at least some care in positioning to achieve a clean sound and a well balanced stereo soundstage.
The Epos style bass driver has a familiar satin finish, mineral-loaded polypropylene cone and a fixed dust cap; the tweeter has a miniature neodymium magnet and25mm alloy dome. Bass reflex loaded via a good size port on the rear, this may need to be tamed by a sock if the speakers are placed near a wall, to help moderate the resulting bass excess. The speakers use fourth-order passive crossovers, so strictly speaking are 'powered' rather than 'active', the latter designation reserved for designs with a separate amplifier per driver fed from an electronic crossover.
Preliminary tests on what turned out to be a first pair revealed a promising enough sound but with a 20dBdeep notch at around the 4kHz crossover frequency (see frequency response graph). Creek thought that this was not correct so sent another pair, where the notch was fixed, but they also sounded rather different; inspection revealed a crossover component of significantly different value, of which more later.
The 'corrected' second sample seemed to have had rather more done to it than just reversing the tweeter phase to fix the measured response notch. The component change may have fixed the notch, but now the sound quality was rather different. It seemed rather forward in the lower treble, lacking the air and sparkle and transparency of the first, and frankly was not as much fun to listen to, notch notwithstanding.
Brief lab tests were carried out. Frequency response measurements showed that the first sample (red trace) was consistently out of phase around the crossover point for nearly all axes. Here the lower treble is also 4dB above the midrange on average, then falling away to -3db by20kHz. There is also a small prominence around 1kHz.The second sample showed much better integration between midrange and treble, with a 1/3-octave smoothed treble extending to 20kHz +/-2dB. Ironically, while the first sample sounded tolerably well balanced, the second sample had lost some of what might well have been an artificial sparkle and clarity heard in the first, and was consequently less transparent, lively and revealing in comparison.
While that notch is directly related to a measured frequency response, this is not comparable to a pickup cartridge or amplifier flaw which necessarily pervades the entire output. With a loudspeaker a response notch may only be visible in the parts of the space over which measurements might be taken, and may not figure strongly in the more relevant room-coupled far-field averaged 'power' response. It may therefore sound nothing like as bad as it looks. Consequently there is rather more to the difference between the two speakers than that seen on our axial response graphs.