Home theaters with bass reflex

 

— a tube installed in the column housing and having an outlet to the surrounding space; often used in subwoofers, but can also be installed in main acoustics. The length of the tube is chosen so that a signal comes out of it, inverted in phase relative to the signal from the front of the diffuser. This has a positive effect on the richness of the sound of low frequencies, in particular, due to the expansion of the bass range. However a phase inverter can create certain "side effects" due to the movement of air in the pipe; but manufacturers usually adjust the acoustics in such a way that this phenomenon is reduced to almost zero. But from the unequivocal disadvantages, specific installation rules can be called: a column with a phase inverter cannot be placed close to the wall.