R&D Report 1983-10 : The design of the prototype LS5/9 studio monitoring loudspeaker. K.E. Randall, C.D. Mathers The prototype of a new medium-power studio monitor is described which is physically small enough to be accommodated in areas where a large high-power monitor would be inappropriate. The main design and performance features are as follows:- A vented cabinet having a volume of 28 litres (1 cubic foot). Two drive units; a proprietary 34mm soft-domed high-frequency unit and a BBC designed 200mm low-frequency unit having a polypropylene diaphragm and a high temperature voice-coil. A low-level cross-over circuit feeds a 50watt stereo amplifier which drives the units separately; the cross- over frequency is 2.4kHz. The axial frequency response is +/-3dB from 56Hz to 16kHz and the maximum sound level is 100dB(A) at 1m on axis measured in a typical listening room using light music.
