A Woofer is not only the nickname for your pet dog, it is also the technical name a loudspeaker driver that is designed to produce low frequency sounds. They usually range from 50 Hz up to 1000 Hz.
A Subwoofer goes even lower, ranging from 20–200 Hz for consumer products. A lot of music enthusiasts have subwoofers in their cars or boats for full and rich audio sound.
While you can buy a reasonable subwoofer for just over $100, they can also cost an astronomical amount. The most expensive car stereo system is the Rogue Acoustic Audio system. Especially created for the reality TV show ‘Street Customs” it costs an amazing $300,000.