The RIAA equalization curve boosts highs and cuts lows during vinyl cutting, with the inverse applied on playback

A standardized equalization curve is applied during vinyl cutting and reversed on playback. During cutting, highs are boosted by about 17 dB at 15 kHz and lows cut by about 17 dB at 50 Hz. Cutting the lows narrows the groove excursion (allowing more grooves per inch and more playing time and lowering noise); the opposite curve applied by the phono preamp on playback restores flat response.

Examples

Plugging a turntable into a line input without a phono preamp sounds thin and bright — the RIAA curve is never reversed, so the cut-emphasized highs and attenuated lows remain uncorrected.

Assessment

What dual purpose does the RIAA equalization curve serve when applied during vinyl cutting?