Paradigm Premier 800F review

The most obvious of those technologies sits in front of the Premier 800F’s 165mm-diameter midrange driver, which has a carbon-infused polypropylene cone with a Thiele/Small diameter of 130mm. In front of it is what Paradigm calls a patented ‘Perforated Phase-Aligning’ (PPA) lens, which it says “increases and smooths its output without colouring the sound”.

The idea of putting a dispersion/phase-alignment device in front of a driver is not a new idea – loudspeaker manufacturers have been putting them in front of tweeters for more than half-a-century, and indeed Paradigm has fitted one to the tweeter on the Premier 800F. But putting one in front of a midrange driver is, while not without precedent, relatively rare. How might such a ‘lens’ “increase and smooth” the output of a midrange driver? 

One reason is fairly obvious. In any ‘cone’ loudspeaker, the cone moves inwards and outwards in pistonic fashion to produce sound. So if the centre of the cone moves forwards and backwards one millimetre, the outside edge of the cone, where it joins with the roll surround, will also move forwards and backwards by one millimetre. 

But because sound waves are quite short (a 4kHz sound wave is 11cm long) this means that the sound wave created at the centre of the cone will be slightly out of phase with the same sound wave that’s being created at the cone edge, and when the waves combine further in front of the driver there will be interference that will cause frequency response variations – increases when the sound waves are in-phase and decreases when they’re out-of-phase.

Essentially what Paradigm is doing with its PPA lens is trying to minimise the deleterious sound-wave interactions while at the same time maximising the useful interactions. I say ‘trying to minimise’ because to do this perfectly, you’d need a slightly different PPA for every frequency the driver is capable of reproducing.

Now take a close look at the roll surrounds of the two bass drivers. Instead of being a smoothly curved piece of material (manufacturers use various materials, including rubber, cloth, foam, thermoplastic, etc), the roll surround of the 800F’s bass driver is both ridged and curved, in a process Paradigm calls ‘Active Ridge Technology, or ‘ART’.

Paradigm says these corrugations enable much greater driver excursion than a standard profile surround and they also enable a driver to deliver higher sound pressure levels for the same input voltage, and with less distortion. Indeed Paradigm says the differences can be quantified as “an astounding, measurable 3dBSPL gain in output and a 50 per cent reduction in distortion”. 

Also, rather than gluing this surround to the cone, Paradigm ‘overmoulds’ the surround onto the cone, which provides a much stronger bond.Paradigm has been granted two US patents for its Active Ridge Technology, which was invented by Paradigm researchers Oleg Bogdanov and Kevin Stitt. 

One of these patents covers the ornamental design of the surround, while the other describes the function of the profile (in part) as “having a cross-sectional profile that varies continuously between each peak and adjacent trough so as to substantially eliminate unwanted stress-induced deformation during displacement of the diaphragm suspension when in use”.