It tells you what frequency range the speaker will reproduce. If a speaker is +/- 3db from 50Hz to 20kHz, then that speaker has a fairly flat response from 50Hz to 20kHz. This means that the speaker can produce sound within 3db of the original material as long as the original material doesn't go below 50Hz or above 20kHz.

How loud the speaker is depends on it's efficiency and how much power you feed it.

Last edited by kaid; 01/20/05 10:09 PM.