The pinnacle of current PSI stereo and sub system development, the Satellite 25-225 system, consisting of a pair of A25-3 speakers and a pair of A225-1 subs, represents the ultimate in 4-way stereo reproduction. The crossover frequencies between the units are perfectly aligned and form a flat frequency response from 30Hz up to 20KHz. The Satellite 25-225 comes with all the technologies of the single units (CPR and AOI), but provides an increased frequency range and SPL. Protecting your investment over time, the Satellite A25-225 system can be used as the basis of a most powerful PSI Audio 5.1 surround sound system.