Mono-a-Mono performs equalisation using a shelving filter. A shelving filter is like a tone control, with one gain at low frequencies, and another at high frequencies. There’s a smooth transition from the low frequency gain to the high.
With Mono-a-Mono, the filter is controlled by two sliders: “Bass Boost” and “Treble Boost”. The values of these sliders represent the gains at low and high frequencies respectively, measured in decibels (dB) relative to that at 1 kHz.
Using different settings for these controls, the user can compensate for errors in the original playback/digitisation process, or simply adjust the tonal balance of the recording to suit personal preference. They can be set to typical values for different recordings using Mono-a-Mono’s “Wizard” function.