20
H = ((fSq + 20.6 .^ 2) .* (fSq + 12194 .^ 2) .* sqrt((fSq + 107.7 .^ 2).*(fSq + 737.9 .^ 2))) ./ ((12194 .^ 2) .* f .^ 4); H(1) = 0;
Figure 18. Final A-weighting Filter Function Although this now serves the “correct” purpose visually, we can see from the amplitude axis that we now have the opposite problem and the gain is being boosted too much (almost 35dB) in the high end which is much too loud at this level [fig 9]. In the conclusion we will look at how this could be rectified. From our results we can see that toneControl() is working as it should, (when loudness = 0), we are seeing magnitude response results that are in keeping with what would be expected for different knob positions corresponding to gain boost and attenuation. Some examples below.
