The factors governing the size of a loudspeaker invariably involve considerations of overall performance, cost, and domestic acceptability. Referring specifically to moving coil drive units and their enclosures, the larger the size of the enclosure the more extended is the bass response, which in turn adds to the scale of the sound by providing a certain low frequency ambience.

Although it is more difficult to maintain the low frequency response of the small enclosure speaker, there are also a number of important advantages associated with a reduction in the dimensions of the enclosure. Thus, it is not unusual to discover a so called budget design that represents really excellent value for money with a performance that can only be surpassed by designs costing a great deal more; sometimes by a factor of three or more.

In this article, the author embarks on a design aimed at satisfying the requirements for low cost, free-standing configuration, and the minimum of dimensions consistent with an adequate low frequency performance.