BBC LS5/1 studio loudspeaker with built in AM8/1 amplifier, 1970-1988.
Used for high quality checking, a BBC document about this speaker stated that, "a monitor speaker must produce the programme signal with the greatest possible accuracy without modification of tonal quality and devoid of colouration". Uses Plessey 15" paper cone LF unit plus two GEC HF units. Has plinth with built-in AM8/1 amplifier. Designed to replace the LSU/10. LS5/1 was the studio version of the LS3/1 speaker (used for OB). The LS5/1 cabinets were larger than the LS3/1 and the tweeters were mounted above the woofer, rather than in front of it.