You can use the controls in the Decay Color section to shape the tonal spectrum of the reverb by adjusting the decay times of the low and high frequency ranges. Low and high crossover points define the cut and boost points of three frequency ranges.For best results, set crossover points at least one octave higher than the frequency you want to boost or cut. To boost a signal at 200 Hz, for example, set the crossover to 400 Hz.Low Frequency Crossover sets the crossover frequency at which transitions from low frequencies to mid frequencies take place in the reverberation filter. The range of this control is from 50.0 Hz to 1.5 kHz.Low Frequency Ratio sets cut or boost ratios for the decay times of the low and mid frequency bands of the reverberation filter. The range of this control is between 1:16.0 and 4.0:1.High Frequency Crossover sets the crossover frequency at which transitions from mid frequencies to high frequencies take place in the reverberation filter. The range of this control is from 1.5 kHz to 20.0 kHz.High Frequency Ratio sets cut or boost ratios for the decay times of the mid and high frequency bands of the reverberation filter. The range of this control is between 1:16.0 and 4.0:1.