Furthermore, it delivers an overall frequency response that holds within an impressive +/-3dB across nearly the whole audio band, alongside a generous 90dB sensitivity. Although the overall response limits are impressive, the trace isn't without a degree of 'character', showing some lack of output in the midband (250-500hz) as well as some excess in the upper mid (700hz-1.5khz).

Perhaps, complementing the relatively high sensitivity, the impedance is quite demanding in terms of amplifier current, twice dropping to around 4.5 ohms, once at the tuned port resonance 35-43hz, and again a little higher up, 110-130hz, the latter a sector of the audio band where typical program levels are quite high. Above 8kHz the impedance also falls, though there's little program energy at these highest frequencies.

The first thing one notices on plugging in and playing the Radiance 3s is just how 'quiet' the enclosures are. The sort of 'cabinet grunge' that normally serves to restrict and obscure detail resolution at the lower end of the total dynamic range seems largely absent here, or at least exceptionally well controlled. The consequence is a speaker that sounds uncommonly 'clean'.

However, perhaps in part as a result of that very low enclosure signature, the mild imbalance through the broad midrange isn't easy to ignore, leaving the upper frequencies here a trifle too exposed. The result is that voices can sound a little too explicitly projected, with a slightly 'cupped hands' or megaphonic effect.

While this certainly makes it very easy to hear song lyrics and speech when the speaker is playing quietly, it also means that things can get a trifle aggressive and shouty when the volume is wound up high. What is unquestionably nice at low volumes starts to get a bit uncomfortable as levels are increased.

While the dynamic range is unusually wide, the actual dynamic behaviour does fall a little short of that obtainable at higher prices. Although it drives the music along with good purpose and weight, the bass end would benefit from rather more grip and tension, while the midband is slightly softened by a degree of time smear, which again serves to take the edge off the expressiveness inherent in the performance.

Stereo imaging is a major plus, as the soundstage shows no tendency to cluster around the boxes and depth perspectives are well portrayed, especially on recordings with a large and believable acoustic, such as choral material.

The sweet and smooth top end is certainly a major strength, as it supplies plenty of subtle detail without ever seeming to draw attention to itself. The annular tweeter used here has long been regarded as one of the better examples around, even appearing on some very exotically priced models, and its performance here, assisted by the DXT lens, is certainly well up to the expected level.

The only real complaint arose when some friends were visiting and we were rocking out with the sounds of Beefheart, Little Feat, Tom Waits and suchlike at relatively high levels. Under these circumstances the slightly 'shouty' character and lack of tight dynamic grip became mildly irritating, so we changed over to a speaker costing six times the price.

Taking cost into consideration, however, and in regular day-to-day use over a period of at least ten days – using a wide variety of material from diverse sources including vinyl, CD, radio and TV – this Acoustic energy acquitted itself very well indeed, and proved most satisfactory and satisfying.