Mechanical amplification

From microgrooves to hi level sound. Sound reproduction and folded flares old but new again, acoustic amplification, together with wide range sound, for example, the internal structure in your mobile phone. It was originally achieved by folding the air passage as it passed from the diagram or cone of the sound driver.

'DIVE for cover'... The ships trumpet speaker uses a compressed air lock to keep it free of salt water. Remember 'Warning! incoming flights landing.