What is a Low Pass Filter

I am told that different filters will alter the quality of the sound and that, even though a filter is screening out inappropriate frequencies, there can be a perceptable altering of the final product that you might or not not like.

This is just one adjustment in your overall system.

Is the sub on the link your subwoofer?
i hope that you didn't pay the hefty 3500$ for a subwoofer
and you don't even know what is the purpose of the low pass filter .. :p
hihi

Another way to look at it, is that some drivers are designed to handle high frequencies (tweeters), some are designed for miidrange (smaller to medium woofers) and some are designed for low frequencies (larger woofers, subwoofers). Filters or crossovers ensure that only the appropriate signals are being sent to each driver. You don't want mid and high frequencies heading to your subwoofer...hence the need for a low-pass filter. Similarly, you don't want low frequencies heading to a tweeter.

harry

Low pass filter means only low frequency signals are sent through and high frequency signals are filtered. Opposite is true for a high pass filter. Your low pass filter is adjustable to allow a range of frequencies 38-65 hertz to be set, anything above is filtered out. Using the lowest 38 hertz setting will only allow that frequency and lower to be seen by the subwoofer, generally 20 hertz the lowest possible to humans. By increasing it more low signal will hit the subwoofer and most likely produce not necesarily more bass but more bass signal attenuation. The gain will allow you to separately adjust the level of the sub over your overall preamp level. To start leave the gain in "0" or neutral and try adjusting the filter to your listening tatses. My guess/taste is a lower setting for HT and higher for music.