Patent ID: 6950524

Claim:
A sound reproduction system comprising electro-acoustic transducer means, and transducer drive means for driving the electro-acoustic transducer means in response to a plurality of channels of a sound recording, the electro-acoustic transducer means comprising sound emitters which are spaced-apart in use, the transducer drive means comprising filter means (H) that has been designed and configured with the aim of reproducing at a listener location (w 1 , w 2 ) an approximation to the local sound field that would be present at the listener's ears in recording space, taking into account the characteristics and intended positioning of the sound emitters relative to the ears of the listener, and also taking into account the head related transfer functions of the listener, wherein the electro-acoustic transducer means comprises at least two pairs of sound emitters, a first pair of said pairs of sound emitters being intended to be positioned more widely apart than a second of said pairs of sound emitters, said first pair of said emitters being suitable for use with a relatively lower frequency band, and said second pair of sound emitters being suitable for use with a higher frequency band, the arrangement being such that in use drive output signals in said lower frequency band are arranged to excite said first pair of sound emitters, and drive output signals in said second frequency band are arranged to excite said second pair of sound emitters, characterised in that the operational transducer span-frequency range is determined by an equation of the form f = ( n ± v ) ⁢ c 0 4 ⁢ Δ ⁢ ⁢ r ⁢ ⁢ sin ⁡ ( Θ / 2 ) where the transducer span Θ is the angle subtended at the listener by a pair of transducers, where n is an odd integer, c 0 : is the speed of sound, Δr: is the equivalent distance between the ears, and v≦0.7.