What is a Low Pass Filter

Viridian, I do not understand your response. Let me ask you this: Why would I want to "attenuate" any frequencies? I am assuming that by "attenuate" you mean that it is modifying the signal above a certain frequency?

thanks,
David

A filter lessens (attenuates) frequencies above or below a selected cut off frequency. Loudspeakers use filters to selectively limit the frequencies sent to individual drivers. A subwoofer input could employ a low pass filter to allow only bass frequencies to be sent to the woofer cones. As the name implies, a low pass filter lets low frequencies pass through unchanged.

Otherwise, your subwoofer would also be receiving midrange signals full force, which would make it much easier to hear its location. Your ears would know that it is not blending as well as could be with your main speakers, as it should 'disappear' when set up well. And as far as a sub trying to do high frequences like cymbals, well, that's really funny to hear.

Hope this adds to your understanding.