Revel’s Performa B15a is one of the nicest home cinema subwoofers one could possibly own. Featuring unique Revel technologies, it offers tremendous low frequency reproduction, enhancing any high end home cinema installation. The B15a subwoofer features a 15″ driver and with its prodigious bass capabilities will do justice to the most demanding home cinema systems. The built-in 1000 watt power amplifier ensures incredible dynamics and control, and along with its reserve capacity it can deliver up to 1400 watts if needed. 

Conventional home cinema subwoofers that offer plain level and crossover frequency controls, usually fail to provide accurate deep bass response due to the interference with the home cinema room itself. Therefore, the Revel Performa 15a subwoofer is equipped with a parametric equaliser that allows a smooth low frequency response to be achieved in hi-end home cinema installations. 

This delivers tuneful and musical low bass reproduction without the boomy and irritating response of typical home cinema subwoofers. The Revel B15a subwoofer seamlessly integrates with the most demanding home cinema speakers and improves performance far above its frequency range, thus creating a holographic three-dimensional soundstage.

By looking at Norris-Eyring reverberation formula, allows some broad generalisations to be made about the effect of size of a dedicated home cinema on the reverberation time, irrespective of the quantity of acoustic panels present. The formula shows that the reverberation time is a function of the surface area, which determines the total amount of absorption, and the home cinema room’s volume, which determines the mean time between reflections in conjunction with the surface area.

As the home cinema room size increases, the reverberation time increases proportionally, if the average absorption remains unaltered. In typical home cinema installations the absorption is due to architectural features such as carpets, curtains, people, etc., and so tends to be a constant fraction of the surface area.

The net result is that in general, large dedicated home cinemas have a longer reverberation time than smaller ones, and this is one of the cues we use to ascertain the size of a space, in addition to the initial time delay gap. Thus one often hears people referring to the sound of a ‘big’ or ‘large’ acoustic as opposed to a ’small’ home cinema room, when they are really referring to the reverberation time.

Interestingly, now that it is possible to provide a long reverberation time in small home cinema installations, via electronic reverberation enhancement systems, with good quality, people have found that long reverberation times in a small home cinema room sound ‘wrong’ because the visual cues contradict the audio ones. That is, the listener, on the basis of the apparent size of the space and their experience, expects a shorter reverberation time than they are hearing.

Apparently closing one’s eyes restores the illusion by removing the distracting visual cue!