What is HP Filter, LP Filter? What do crossovers do?


Hey guys! I decided to do another video for you to explain what crossovers are and how they should be set in your car audio system. I also decided to clean off the dresser behind me in the video, because I think I looked like such a slob in the last one! Anyways, chores aside, let’s talk about crossovers. On many of the newer head units these days, if you scan through the audio settings you will see things like HP filter, LP filter and when you select them a few options for frequencies to select from. You may also see these settings on your amp and not really know what they do.

In the simplest way to describe this, crossovers are frequency filters. They allow us to filter out certain frequencies to certain speakers. So on your interior speakers, that would be your HP or High Pass Filter. High Pass means we’re only allowing the higher frequencies to play through, so this is what you want to adjust for your interior speakers. LP or Low Pass means we’re only allowing lower frequencies to play through. So ideally you want your interior speakers playing what they’re best designed to play, about 60-80 hertz and up and we have our subs playing about 60-80 hertz and down. The important thing to remember is you don’t want any gaps between these frequency settings as then you’ve cut them out of your stereo system all together. So make sure the cut off is about the same on both your low pass and your high pass filter.


The other important thing to remember is you never want to use both the crossover setting built into your head unit AND the crossover setting on your amp. Use one or the other. So never use the LP filter on your head unit and the LP filter on your subwoofer amp, that can cause weird phasing issues. Same thing on the interiors, if you’re using a 4 channel amp, either use the HP filter on the amp or the HP filter on the head unit, but don’t use both.

I hope this helps clarify what crossovers are, how they work and what they can do for your car audio system. If you have questions about where you should have your crossovers set at, just please comment and I’ll respond and help you out. Also, if you guys like what you see here, please submit this site to one of the social networking links, I would really appreciate the support. Thanks for stopping by and checking out the site!