Abstract: A method of producing an acoustic radiation pattern, the method comprising receiving an input audio signal representing a first acoustic radiation pattern, generating an acoustic monopole and an acoustic dipole based on the input audio signal, wherein generating the acoustic monopole and the acoustic dipole is to produce a second acoustic radiation pattern substantially similar to the first acoustic radiation pattern.

Abstract: A method of producing an acoustic radiation pattern, the method comprising receiving an input audio signal representing a first acoustic radiation pattern, generating an acoustic monopole and an acoustic dipole based on the input audio signal, wherein generating the acoustic monopole and the acoustic dipole is to produce a second acoustic radiation pattern substantially similar to the first acoustic radiation pattern.

Abstract: A speaker arrangement is described, suitable for improving the sound quality of a small size first speaker. The arrangement comprises a cavity, to which the first speaker is acoustically coupled. A second speaker is also acoustically coupled to the cavity, and the first and second speakers are excited in phase with each other. The first speaker may be an earphone speaker tuned to be held to a user's ear, whereas the second speaker may be a larger ring alert speaker with lower compliance than the first speaker, both of which are incorporated in the same mobile phone. By exciting the second speaker in phase with the first speaker, the second speaker will aid the smaller first speaker's reproduction of sound, particularly in the lower frequency range.