Firstly, I should declare an interest in KEF. As a youngster, I was enamoured of the brand, and always wanted a pair of KEF Concerto loudspeakers, an ambition never achieved (although I have since owned other KEF models). Financial interests aren't the only potential sources of bias in reviews.
Of course, things have come a very long way since the KEF Concerto. In particular, in recent times, KEF has been keen on coaxial drivers, with the tweeter mounted in the centre of a larger unit. KEF calls its system the "Uni-Q driver array", and that is what KEF has installed in its R700 floor standers.
The 25mm aluminium dome tweeter is responsible for frequencies of about 2900Hz, while the surrounding 125mm aluminium cone mid-range driver carries the load between 500Hz and 2900Hz. Below, 500Hz is delivered by two 165mm bass drivers, one mounted above the Uni-Q, one below.
Given the efforts that KEF has put into making each loudspeaker have a single-point source — a virtual one in the case of the bass — it's a pity that the speaker sits just a little too low for ear-level tweeters. These are just 800mm from the floor. On my couch, which is pretty standard, my ears were at the level of the top woofer, rather than the tweeter.
The enclosures are bass reflex loaded with two ports on each. Foam bungs are provided to insert if necessary to tame the bass for close wall placement. Rather heavy die-cast aluminium feet are provided, which screw onto the bottom of the speakers, providing greater side-to-side stability. Spikes screw into these, and can be adjusted from the top using a hex key.