Produced between 1970 and 1973, the Sansui SL-7 (and its white-finished sibling, the SL-7W) was a slimline, flat-panel loudspeaker priced at roughly 480 DM or ¥18,600 per unit. Designed for shallow wall-mounting or floor placement via optional aluminum legs, it reflected early 1970s aesthetic trends toward ultra-thin high-fidelity equipment.
 
Design and Engineering
Drivers: Features a 20 cm kraft-pulp cone woofer paired with a passive "Drone Cone" (a cone lacking a magnetic circuit used as a passive radiator to extend low frequencies) and an aluminum dome mid/high presentation alongside a 2.5 cm hard metal-diaphragm dome tweeter.
Cabinet Construction: Built using specialized plywood and particle boards featuring traditional Japanese Kumiko lattice craft elements on the baffle.
Acoustic Signature: Contemporary Japanese audio reviews noted a distinct forwardness in the mid-and-high frequencies—characteristic of the bright "Sansui sound" of the era—making vocals punchy and clear.
 
Legacy and Context
During this specific period, Sansui Electric was deeply engaged in high-end audio innovations and also served as the Japanese importer/distributor for JBL, heavily influencing their domestic speaker experiments. While niche, slim profile speakers like the SL-7 are remembered as elegant space-saving engineering exercises.