As with all the equipment, though, there's also a desire to reuse existing equipment where possible, to avoid spending money on equipment that may only be used a few times a year.
main front of house speakers - these are two large units consisting of 15" bass drivers and large dynamic hi frequency units. They were originally built for mains powered PA use quite a few years ago, and designed to be not only clear sounding but efficient. They have done well with a variety of types of music, particularly acoustic performances. These speakers also have stands that can raise them to head height to carry the sound across the crowd. These units are rated at over 200w rms each.
monitor speakers - these are also reused from a main powered system, and consist of 12" bass drivers and piezo tweeters. They can be used as vertically placed audience speakers, or as wedge monitors allowing performers to hear what is being amplified (useful outdoors, where of course there are no or few reflections of the sound as would be natural in a hall). Approx rating 100w rms each.
column speakers - known as the 'red' speakers - these use some high efficiency 8" drivers bought very cheaply in an end of line sale, and piezo tweeters. The column design also makes them a little more directional, making them even more efficient if placed correctly. The multiple speakers also allowed impedance options: 2 Ohms (useful for making maximum use of low voltage amplifiers) and 8 Ohms (a more standard impedance).
pannier speakers - two compact speakers designed to be transported and/or used by bike. Quick construction information here.