Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by [CPC: H04R7/00] or [CPC: H04R31/003], not provided for in any of its subgroups
Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by [CPC: H04R7/00] or [CPC: H04R31/003], not provided for in any of its subgroups