Frequency Response

If you have ever checked the specifications of any audio device, you would have see the frequency response ratings. Frequency Response of a device describes its correctness in terms of paasing the signal from its input to its output with regard to the signal amplitude & frequency. This tells us the usable range of signal frequencies with this device.

Freq. response is typically specified as below:

Here, ±3dB qualifier tells the torelance of the specification, meaning, the maximum deviation in the output level that we can expect over the stated range (30Hz - 18kHz), if the input level remains same at all frequencies.

Usually the output level deviations occurs at the frequency range boundaries. And, in most devices, ±3dB is considered as “normal” deviation. Even if the tolerance is not specified, one can safely assume it to be ±3dB.

With the advance of electronics, nowadays, most of the electronic devices such as power amplifiers, cross overs etc., exhibit flat frequency response curves. The devices, that needs to be looked into for frequency response curve are electro-magnetic transducers such as loudspeakers, subwoofers and tweeters.