KEF C25 Bookshelf speakers

Moving up from C15 to the C25, we find an internal volume increase from 3.5 to 6.8 litres and marginal specification increases under all headings: sensitivity up to 87dB, power handling up to 70 Watts and maximum SPL 106dB. Apart from the larger enclosure, all the beefing up of performance can be attributed to the change from a 110mm main drive unit to KEF's new 160mm unit with a lightweight polymer diaphragm. The tweeter is the same as in the C15 and all other constructional features are as near as I can see identical.

The same operating instructions are supplied for both models so I followed the same test procedures (including a room plot of frequency response which confirmed the C25's higher sensitivity and slightly delayed bass roll-off). Used at a good one metre from the walls, the C25 gave a little more than the C15 in terms of lower mid range power, and was noticeably more sensitive. Yet music with any important bass content - classical or pop-had less impact than most people would like, and signs of cabinet resonance could be detected. Again, moving the loudspeakers close to the wall, as KEF recommend, produced a better balance and feeling of depth. As the same tweeter is used, the presence and treble smoothness were again very satisfactory.