Jerry Werth

Recently purchased the SDM combo pack. Everything went very smooth until I attempted to set crossover frequencies in mid amps. When adjusting my mid level amps I receive a signal but I cannot adjust the crossover frequencies to what is being outputted from my deck with CD installed. I turn the frequency knob to max and min with no avail . My low level amp adjusted with no issues. I have tried multiple different frequency tones with no lick. Any advise would be appreciated .