an antique soviet woofer 5gd-3 from vintage acoustics symphony

1960s 5gd3 60s 70s acoustics alnico antique bracket cap cardboard case cases cast cobalt contest desk entertainment fm frequency funky gray helmholtz home live loft melody old perforation plywood radio rare reggae report resistance resonant resonator retro shielding sing soviet speak speaker speakers spy stereo symphony threeway ussr vintage volume woofer