Frequency Response is the Frequency Range versus Amplitude. In other words, at 20 Hz, a certain input signal level may produce 100 dB of output. At 1 kHz, that same input level may produce 102 dB of output. At 10 kHz, 95 dB, and so on. A graph of all the frequencies plotted versus level is the Frequency Response Curve (FRC) of the monitor.
When you see a Frequency Response specification for a monitor, the manufacturer is telling you that for a given input signal, the listed range of frequencies will produce output within a certain range of levels. For example: 20 Hz to 20 kHz +/- 3 dB. For these frequencies, the monitor will output signals that are within a 6 dB (+/- 3 dB) range. This does not mean that the speaker won’t reproduce frequencies outside this range, it will! But frequencies outside the range will be more than 3 dB off from the reference level. For further information, see also May 5th’s inSync Word For The Day, “Flat Response”, available in the inSync Archives.
