Power supplies, loudspeakers, crossover networks, and filters.

If a modest output from one of the smaller power amplifiers (described in EPE Online May '02) is all that is required, dry batteries represent a suitable power supply. However, when the output is expected to exceed the half-watt level for sustained periods, a mains power unit is more appropriate.

Savings in the cost of batteries will quickly cover expenditure on components. Compromises, inherent in the design of loudspeakers, give rise to limitations, which are normally overcome by the use of two or more units and a crossover. Power supplies, loudspeakers and associated networks are the topics covered this month.