The woofer is generally the largest driver in the system which covers the bass and mid-range frequency.

The tweeter is generally the smallest driver in the system which covers the highest frequencies.

The grill is the cloth and frame used to cosmetically conceal the drivers without affecting the sound. Ohm now uses black grills in almost all cases. In the past, brown and brown/black mixes were used; but every ”brown” turned out differently. Now they are all black (except on some current white speakers, we have white as an option).

The crossover is the electrical circuit that protects the tweeters from the low frequency energy that is reproduced by the main drivers. This can only fail, in rare instances, from overdriving the speakers.