In this video I apply sand paper to the speaker cone of a Celestion G12M25 Greenback Guitar Speaker Reissue. I'm sanding down gradual amounts of the paper cone to hear how if influences the sound of the speaker. The hypothesis is that the crisp and probably quite symmetrical surface structure of a new speaker makes it sound harsh and synthetic. So does this take us any closer to the good old Pulsonic Greenbacks of the 60s and 70s? Let's go ;-)