high frequency speaker soviet-made 3gd-31, 5 gdv-1-8 . revision and repair of vintage acoustics

3gd31 abandoned abstract antivibration audio bass beat box car carbon case destroyed disassemble disassembled fiber frequency gdv18 glue high interior listen loudspeaker membrane midrange music musical paper passive plastic pva radiator record russian sealing shelf silk song soviet speaker studio system technology tweeter twitter ussr vega vibration vintage white wood wooden