The sound of loudspeakers is heavily influenced by room acoustics. In some cases the room shape and especially the furnishings offer less than ideal conditions for the optimum set-up of loudspeakers, sometimes resulting in bass reproduction which is too strong. This happens mostly in small rooms or when loudspeakers are positioned close to walls.

A two-piece bass control plug is provided that can partially or fully close the port, so the system can be tuned to overcome the influence of room acoustics or improper speaker placement. This way, the upper bass output will be reduced, while the deep bass area will be slightly increased. This results in a deep, tight bass sound.

ELAC vented loudspeakers use bass reflex tubes with different lengths and diameters (45, 59, 60, 62 or 70 mm).

Here is a list of two-piece bass control plugs and their matching bass reflex tubes:

• use 55/30 mm outer/inner diameter rubber foam pipes with 45 mm bass reflex tubes,
• use 70/40 mm outer/inner diameter rubber foam pipes with 59 / 60 / 62 mm bass reflex tubes,
• use 82/47 mm outer/inner diameter rubber foam pipes with 70 mm bass reflex tubes.