Loudspeakers & Headphones Flashcards
All 5 cards in this deck
Which effect do moving-coil loudspeakers and headphones use to produce sound?
The motor effect.
What are the steps by which a moving-coil loudspeaker produces a sound wave?
e.g. an alternating current in the loudspeaker coil
- The current creates a magnetic field around the coil, which interacts with the field of the permanent magnet.
- The resultant force makes the coil and cone move.
- When the current reverses, the force reverses, so the cone vibrates and produces pressure variations in the air — a sound wave.
What do loudspeakers and headphones convert?
Variations in current in an electrical circuit into pressure variations in sound waves.
True or false? The frequency of the sound from a loudspeaker is the same as the frequency of the alternating current in its coil.
True. Each cycle of current gives one back-and-forth vibration of the cone.
What makes the sound from a loudspeaker louder?
A larger current in the coil — a bigger force moves the cone further, giving a larger amplitude sound wave.