ano po difference ng low-pass crossover and high-pass crossover in terms of its purpose? velodyne cht has both, selection for low-pass crossover ranges from 40hz - 120hz while high-pass crossover has 80hz and 100hz selection. what's the best high-pass and low-pass crossover for AVR speaker set-up to small and sub setting to LFE?
By definition, a low-pass filter (not crossover) allows frequencies lower than the designated point to pass through. A high-pass filter is the opposite - higher frequencies pass through.
What I referred to in my previous post was the setting in the AVR, which is a low-pass filter (LPF) for the LFE channel. The settings at the sub itself are different.
The LPF in your sub will determine the maximum frequency that the sub will reproduce. Normally, this is set to the highest level and then the actual frequencies which are sent to the sub are determined by the settings in the bass management system of your AVR (basically crossover points and LPF for LFE). In your case, set it to 120 hz.
The high-pass filter that you mention sounds like an output. It sounds like the type of connection wherein you send the full signal to the sub and then hook the sub to the main speakers. Between the sub and the main speakers, the high-pass filter will be activated so you can send frequencies above either 80 hz or 100 hz. This type of connection is not used very much anymore. It's better to let the AVR handle the bass management.
Quite often, the sub has a third filter which is called a subsonic filter and is actually a high-pass filter. It will determine the lowest frequencies that the sub will reproduce. A typical subsonic filter is 35 hz or 20 hz. It basically limits the bass you can reproduce.