I have reviewed the AVI ADM 9.1 active speaker system. This is a distinctive system, in that it builds amplification – both pre- and power amps – and a DAC into the loudspeaker cabinets. There is a remote to control volume and to select between two digital inputs or an analog input.
Why distinctive? Well, most consumer hi-fi is based on passive speakers with an external amplifier. There are lots of active monitors on the market aimed at the professional audio engineer, but most of these lack the pre-amp, DAC and remote.
What is an active speaker? Read the review; but in a nutshell it is one where each speaker driver has a dedicated amplifier, so that the crossover, which divides the audio signal into frequencies suitable for each driver, works on a low-level signal rather than one that is already amplified. This is well-known to reduce distortion. It also means that the amplifiers can be tailored exactly to the characteristics of the speaker drivers, since they are the only ones they ever have to drive.
It raises the question: why are there not more active systems in consumer hi-fi? The short answer is that they do not sell that well, because they are inherently more expensive – you need at least double the number of amplifiers, presuming a two-way loudspeaker.
The long answer, claimed by AVI, is that the hi-fi industry is wedded to the idea of an upgrade cycle that keeps customers buying more. Passive systems, with several separate boxes, are more amenable to that process.