Describes both direct radiator loudspeaker and horn loudspeaker design in detail, with Passive Networks, Acoustics, Measurement techniques and worked examples. Possible new material includes the Q1 vented enclosure alignments, the Q1 and AQ2 Constant-Voltage passive crossover networks, the Resonant Bass Bin and a different way to optimize low frequency horns. Also included is the Pollack Equalizer, that may give the audio presentation of the classic 'Mirrophonic' loudspeaker.