Woofers: Also known as door speakers, are not to be confused with subwoofers, and generally cover the midrange frequencies of the sound spectrum. These drivers tend to vary in size from 4″ drivers to the most common 6.5″ drivers. Smaller door speakers are generally limited to the mid and mid-high frequencies while larger 6.5″ woofers will reproduce frequencies accurately down to the low-mid part of the sound spectrum.
The frequency range of the common door speaker will brighten up an electric guitar, punch the slap of the snare drum, warm up the acoustics of steel toms, bring out the drama of a violin and make you feel the brashness of a saxophone. The mid frequency range is also where you will find the vocals in your music and upgrading your door speakers from a factory speaker system is always beneficial to the sound quality of your vehicle and your music.