Electromagnets were being normally Utilized in musical instrument amplifiers cabinets properly in to the nineteen fifties; there have been financial personal savings in Those people working with tube amplifiers as the field coil could, and typically did, do double duty as a power source choke. This increases the acoustic—electro/mechanical impedance https://speaker51593.dsiblogger.com/62565389/the-5-second-trick-for-miffy-speaker