Rear bass reflex acoustic systems

Rear

— acoustic systems in which there is a phase inverter (FI; see "Acoustic design"), displayed on the rear wall of the speaker. Most often this is the only FI, however, in some models, it is supplemented by an air duct with a front or bottom location (see the relevant paragraphs).

Recall that from an acoustic point of view, it is impossible to say unequivocally which location of the phase inverter is better — a lot depends on other design features, as well as on the personal preferences of listeners. But what this feature definitely affects is the requirements for the installation site. In order for a speaker with a rear duct to sound reliably, without distortion, it should not stand close to a wall or other similar obstacle: it is necessary that the distance between the rear wall and the obstacle be at least 3 cm, and ideally no less than the diameter of the bass reflex tube . This somewhat limits the possibilities for installing speakers. On the other hand, this layout option allows you to experiment with the sound to a certain extent — by changing the distance from the wall to the output of the FI, you can slightly change the colour of the sound.

As for combinations with other options — front or bottom FI — such combinations make the speakers less dependent on installation conditions: the presence of an obstacle behind the speaker and the distance to it do not affect the sound as much as in models with only a rear bass reflex. On the other hand, additional air ducts significantly affect the dimensions and cost of the speakers, and the need for them does not arise so often. Therefore, systems with such equipment have not received much distribution.