:-\ hi, does this circuit need a pre-amp or it can drive power amp directly? I can't find potentiometers stated in the diagram here in our place we have here 50k and 25k pots we don't have 47k and 22k. Can I use them? Is there any effect in the cut-off frequency of the circuit? Does the input of this circuit need a low output from crossover? Pls. advise. thanks, almer Project Link: http://www.electronics-lab.com/projects/audio/008/index.html