Horn loudspeaker

A loudspeaker comprising a driver for generating sound waves over a range of frequencies having a sound outlet port, and a horn having a channel extending therethrough from an inlet end to a mouth, said horn being mounted on the driver with the inlet end of the channel acoustically sealed on the port of the driver, the channel having a first portion extending from the driver and a second portion extending from the first portion, the first portion of the channel having a throat of minimum cross section adjacent to the port of the driver, the second portion of the channel of the horn having cross sectional areas increasing as the square of the distance from the first portion of the channel, said first and second portions of the channel having substantially the same cross sectional area at the interface of said first and second portions, and the cross sectional area of the first portion of the channel increasing with distance from the throat of the channel at a rate of increase increasing with distance from the throat of the channel from a rate less than the rate of increase of the second portion of the channel at the interface between the first and second portions of the channel.