Researchers in the US have made a graphene loudspeaker that has an excellent frequency response across the entire audio frequency range (20 Hz–20 kHz). While the speaker has no specific design, it is already as good as, or even better than, certain commercial speakers and earphones in terms of both frequency response and power consumption.
Loudspeakers work by vibrating a thin diaphragm. These vibrations then create pressure waves in surrounding air that produce different sounds depending on their frequency. The human ear can detect frequencies of between 20 Hz (very low pitch) and 20 KHz (very high pitch), and the quality of a loudspeaker depends on how flat its frequency response is – that is, the consistency of the sound it produces over the entire 20 Hz–20 KHz range.
"Thanks to its ultralow mass, our new graphene loudspeaker fulfils this important requirement because it has a fairly flat frequency response in the human audible region," says team leader Alex Zettl of the University of California, Berkeley. He told physicsworld.com that the fact that "graphene is also an exceptionally strong material means that it can be used to make very large, extremely thin film membranes that efficiently generate sound".
This new graphene audio transducer technology should be on the shelves soon. To read more, click here.