Floorstanding loudspeakers — Revel F36

Revel lists the F36 as a 2.5-way floorstanding loudspeaker with three 6.5 inch aluminium-cone woofers and a 1 inch aluminium tweeter, the bigger of the two Concerta2 towers. Harman developed the series over more than two years to replace the 2005 Concerta range. Buyers choose between gloss black and gloss white cabinets.

Key specs that matter

Rated sensitivity is 91 dB measured at 2.83 V and 1 m, into a nominal 6 ohm load. The amplifier power range suggested by Revel runs from 30 W to 200 W. Bass extension is given at three points - 51 Hz for -3 dB, 45 Hz for -6 dB and 33 Hz for -10 dB. Crossover frequencies are 600 Hz and 1.8 kHz. Height, width and depth come to about 112 x 24.5 x 30.5 cm, and one F36 weighs around 22.7 kg. The box is vented by a port that fires out of the rear panel.

Engineering and use context

Rather than adding a dedicated midrange unit, Revel uses the top driver as a woofer-midrange that covers the whole low band together with the two woofers beneath it. The dividing network that separates those lower drivers from the upper one was patent-pending at launch, and the company links the greater cone surface of this layout to system sensitivity above 90 dB. For the tweeter, a waveguide and acoustic lens bring its off-axis behaviour into line with the woofer-midrange around the crossover. Its magnet assembly has a big cavity behind it, vented around the edge, and with a compliant diaphragm surround this drops mechanical resonance to 800 Hz - Revel compares that with a typical 1.5 kHz - which let the engineers set the upper crossover an octave lower. Cone material is Micro-Ceramic Composite, a Harman-patented sandwich of ceramic over an aluminium core. Revel designed the transducers with computer modelling and checked prototype symmetry with laser measurement. The patented Constant Pressure Gradient port keeps the pressure change along its contoured duct nearly constant. The enclosure uses curved sides with extensive bracing, grilles held by magnets and no visible screws.

Pairing

According to Revel, the high sensitivity of the Concerta2 towers suits many amplifiers, even modestly powered receivers. Within the series, a pair of F36 can be combined with the C25 centre and the B10 powered sub for multi-channel use.

Alternatives

The Revel Concerta2 F35 is the slimmer tower in the range, built around three 5.25 inch woofers.