Pair of white KEF R800ds rear surround speakers.   Each speaker is a dual dipole unit consisting of two Uni-Q driver arrays designed to work out of phase to create a stunning three dimensional dynamic sonic effect in order to form the illusion of actually being in the film itself completing your home theater setup.  The R800ds dipoles turn out to have a neat crossover trick. Like a classic dipole, they fire along your walls and crossover between the high and mid frequencies at 2.5kHz. However, the manual also shows another crossover point of 300Hz for what looks like a simple two-way speaker. Below that frequency, the speaker radiates as a monopole. KEF call this 'two-and-a-half-way.' The reason for the change in radiating pattern is that a dipole struggles to be efficient at low frequencies unless it is very large. Says KEF: 'We flip to a monopole so that the R800ds can deliver some decent LF.'


SPEC's
Type: 3 way, 4 driver satellite loudpeaker system
Frequency Response: 90Hz to 45kHz
Recommended Amplifier: 25 to 100W
Crossover Frequency: 300, 2500Hz
Impedance: 8Ω
Sensitivity: 85dB
Bass: 2 x 130mm (5.25inch) aluminum cones
Tweeter: 2 x 25mm (1inch) vented aluminum dome
Dimensions: 180 x 350 x 184mm (7.1inch X 13.8inchX7.2inch)
Weight: 7.4kg (13.6lbs)