March on washington anniversary speakers for cars
A subwoofer or sub is a loudspeaker designed to reproduce low-pitched audio frequencies known as bass and sub-bass , lower in frequency than those which can be optimally generated by a woofer. The typical frequency range for a subwoofer is about 20- Hz for consumer products, [1] below Hz for professional live sound, [2] and below 80 Hz in THX -certified systems., ...1
3