Louder Than Life
Sydney Morning Herald
Monday June 17, 2002
Active loudspeakers are rarities in the world of high fidelity. Unlike ordinary passive loudspeakers, which must be connected to a hi-fi amplifier or receiver, active loudspeakers are self-powered. All you need to do is connect a CD player directly to the speakers.
DanA Digital's [act:eve] 108:dB has all the design features that enable active loudspeakers to deliver far superior sound quality than their passive counterparts.
The most important of these is that each of the three drivers in the 108:dB is driven by its own amplifier. A small, solid-state Class-A power amplifier drives the 108:dB's 25mm diameter soft dome tweeter.
The use of Class-A mode is significant. Almost all solid-state amplifiers operate in Class-AB mode, where the audio signal is "shared" between two or more output transistors.
The problem with this is that distortion is introduced every time the audio signal switches from one transistor to the other. In a pure Class-A design, a single transistor handles the entire audio signal.
A valve amplifier drives the 140mm mineral-filled polypropylene-cone midrange driver. The use of triode valves means DanA achieves very high power output, yet is still able to operate in Class-A mode.
Amplifier efficiency is also increased because the amplifier handles only a small portion of the audio range, between 92Hz and 4kHz.
To ensure the valves run cool, they're mounted on top of the speaker cabinets, where they're protected by a metal cage.
Low frequencies are reproduced by a side-firing 210mm diameter paper-coned bass driver, driven by a Class-AB solid-state amplifier.
Although this amplifier has the inevitable transistor switching distortion, it's not audible because the distortion occurs at frequencies that are too high for the bass driver to reproduce.
Using a separate amplifier for each driver has many advantages. The greatest of them is that there's no need for the crossover network that's essential in passive speaker designs. Such networks absorb amplifier power and introduce phase distortion. In an active design, all the amplifier's power is delivered directly to the speaker and there's no phase distortion.
We found the sound quality of DanA's [act:eve] 108:dBs to be effortless and natural, with a level of purity that made us forget the speakers were in the room. The tonal colour across the midrange was glorious: rich and warm but at the same time detailed and transparent.
Bass response was extended and powerful; you'll have no need to add a subwoofer.
Before gasping at the price, $14,990, remember that it includes not only a pair of loudspeakers but also four solid-state amplifiers, two valve amplifiers and six electronic filters. Far better to listen to these speakers first, after which their price tag will be the last thing on your mind.
Infofile
DanA [act:eve] 108:dB Active Loudspeakers
DanA Digital Pty Ltd, PO Box 225, McArthur Square, NSW 2560
(04) 0794 8314
info@danadigital.com
www.danadigital.com
© 2002 Sydney Morning Herald