A LOUDSPEAKER cabinet. Its most important function is to improve BASS response by forcing the sound waves produced at the rear half of the loudspeaker:

  • to travel through an acoustic labyrinth, along a distance which, at the exit point, is equal to roughly half the WAVELENGTH of the RESONANCE frequency of the labyrinth, so that the sound emitted at the exit hole is in PHASE with that emitted from the loudspeaker itself;
  • back into the sealed cabinet where they are trapped, producing increased acoustic resistance to the movement of the loudspeaker, resulting in greater effective power of the speaker movement.