Originally Posted by The Wizard

I have never heard of somebody attempting to bandpass a subwoofer before. If you set the low-pass at 40hz, the filter will start to filter out any frequency above 40hz. Then you set the high-pass at 80hz, which will start to filter out any frequency below 80hz. Correct me if I am wrong here but this is not making any sense in this old noggin of mine. Based on the above settings are you not in reality filtering out the frequencies that we want to hear from a subwoofer? The principal of bandpass settings make a lot of sense on a mid-bass driver where you need to filter out the high frequency and the really low frequency where we want the sub to take over, but why would we do that on a subwoofer?