[old_tv_nut]

To give you an idea, the crossover frequencies for a three-way loudspeaker may be around 500 Hz and 3500 Hz. In other words, the woofer reproduces frequencies from its lowest possible response (maybe 40 Hz or less on a good speaker) up to 500 Hz; the mid range reproduces the range from 500 Hz to 3500 Hz, and the tweeter reproduces frequencies above 3500 Hz to its highest capable frequency (at least 10,000 Hz to qualify as HiFi, and often 20,000 Hz).

Subwoofers may have a crossover around 80 Hz, so they reproduce frequencies of 80 Hz and lower.

Examples of low-fidelity frequency responses:
The typical telephone response used to be about 300 Hz to 3400 Hz, adequate for voice recogniton but lousy for music. AM radio network lines were equalized to carry a wider range, from low bass up to about 5 kHz. AM stations and AM radios also limited the highest frequency to 5 kHz, to prevent interference from adjacent stations on the dial, which otherwise could produce a continuous 10 kHz tone in the sound.