Slope of target

Information about the target slopes : with standard loudspeakers (dome in high frequency and closed or bass-reflex box in lows) and in a mid size room, at a distance of about 3m, the bright timbre target is nearly -1.05dB/oct, the balanced is -1.4dB/oct and the warm is -1.75dB/oct. The Harman slope (see Olive in AES papers) is also about -1.75dB/oct with a prefered LF target similar to LFtarget = 205 (AES convention paper 8994). The new Dolby Atmos Music target from 2021 is near -1.5dB/oct above 1.6kHz with LF target = 304.

Also read EVALUATION OF ROOM CORRECTION PRODUCTS in this FAQ where the best corrections found in Sean Olive’s tests show a continuous slope of about -1.2dB/octave.

Another way to have an idea about the target slope, you can use target curve calculator.