Studio-E - Vintage JBL K130 & K140. The 130 was amazing for guitar and the 140 amazing for bass! Not sure new technology has yet captured their glory. Both now available as
JBL K130 15" ALNICO SPEAKERS | Reverb
Can't Separate JBL Speaker from Baffle Board | Fender Stratocaster Guitar Forum
JBL K130 15" AlNiCo Extended Range Musical Instrument Loudspeaker - pair | Stereo, Home Cinema, Headphones Components