The advantages offered by loudspeakers placed in corner locations are often overlooked by designers and installers of sound systems.  Three major advantages are high Q factor, better speaker loading and improved bass frequency reception.

Corner enclosures mounted next to a ceiling have a minimum Q of 8, whereas a speaker mounted on a wall has a minimum Q of only 2.  This indicates more directivity and specific area coverage, which permits a desired sound pressure level to be reached with the least acoustic  power feasible.  Thus, the SPL of the reverberant field (the sum of all acoustic power being fed into it) is kept as low as possible.

Just as putting a loudspeaker on a baffle increases cone loading, corner locations improve the speaker cone's coupling to the air.  This allows more of the speaker's energy to be efficiently converted into sound pressure.

Bass frequency reception is aided by the utilization of the walls and ceiling as part of the enclosure in a way analogous to expanding the mouth of an exponential horn.  Consequently, more directivity is afforded over the omnidirectional bass frequencies.

For best results, corner speakers should not be placed in rooms with an opposite wall closer than one half the wave length of the lowest frequency to be reproduced.

This distance is found by dividing the lowest frequency into 1130, and taking one-half of the result.  For example, 40Hz has a wavelength of 28 feet (1130÷40).  One half is 14 feet - the minimum distance to the opposite wall.