• All sections
• H - Electricity
• H04R - Loudspeakers, microphones, gramophone pick-ups or like acoustic electromechanical transducersdeaf-aid setspublic address systems
• H04R 1/38 - Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means in which sound waves act upon both sides of a diaphragm and incorporating acoustic phase-shifting means, e.g. pressure-gradient microphone

Patent holdings for IPC class H04R 1/38

Total number of patents in this class: 153

10-year publication summary

Principal owners for this class