JBL Set of Model H5039 Horns and Model 2310 Lenses
How do the 'acoustic lenses' on old Hi-Fi loudspeakers work? - Quora
Improved SAW Lens | diyAudio
The superb JBL L-300 was based on one of their studio monitors. 3-way design with 15-inch bass reflex woofer, acoustic lens ho… | Vintage speakers, Loudspeaker, Jbl