Hi pass / lo pass

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Atom Bomb

Atom Bomb

Wtf is a PRS
Rather then all the sceince of how they work, and what not could some explain to me when i might want to use a Hi pass filter or a low pass filter?

The desried end result of using one and where one might apply it.

That may be unclear. but i'll come back later and fix my wording in the event of confusion.
 
A high pass filter is an EQ filter that allows frequencies above the cutoff to pass through while frequencies below are cut out (or cut down/attenuated.) A low pass is the opposite, a filter that allows freqencies below the cutoff to pass while those above it are cut.

When you would want one?

Lets take vocals for example . . . eh, female vocals. There are frequencies present on the vocal track, that you may not even notice. So if you put a high pass filter on it, you take out the low frequencies that take up speaker energy and sonic room (even if you don't notice it) and this can open up the vocal, make it more "airy" and make mixing easier.

You can apply the same concept to a kick drum. Putting a low pass on it can take out the frequencies that don't need to be there.

Now, here's my standard disclaimer. I'm not a pro. I don't even get to record that often, so someone may come in later and show me to be all wrong. But this information is how I understand the high/low pass filters.
 
Hi pass means "The high sounds pass through". Use it when you don't want any tone lower than the threshold in a sound.

Low pass is the opposite.
 
Say you/re getting some low-end rumble from whatever...use a Hi-pass to block it (roll it off).

Maybe your bass guitar has too much upper-end string noises...use Low-pass to block it (roll it off).

That's kinda simple...but you get the idea.

One thing to play arttention to is the frequncy where the "pass" happens.
Many Lo/Hi pass filters are shelf filters with a preset frequency and slope...so it's not always a perfect fit for anything.

Lots of folks will engage the Hi-Pass filters on their mics all the time as an automatic thing...but I think it's best to hear the source with & without first.
 
If your recording Darth Vader you wouldn't want to use either of the passes!:laughings:
For you need to hear the high end breathing assisted mechanics as well as capturing the low end of his voice, at the same time.





:cool:
 
Example of low pass filter:

I find bass drum samples have too much "click" to the sound, so I use a low pass filter. It lets the lows pass through but rolls off the top so it sounds more muffled.

And of high pass filter:

I use a high pass filter on my electric piano sounds. It lets the highs pass through but rolls off the bass. If I don't use that the left hand of the electric piano can be real muddy and compete with the bass guitar or bass synth.

I aim to use no eq. When I do use it I tend to either roll the top or bottom off with high or low pass filters. High and low pass filters in general don't mess with the sound a lot, they tend to remove sound and leave the rest the same. :)
 
I personally try to never high/low pass anything. It seems like a pretty hardcore way to "fix" something. As always, getting the best source sounds you can and using good mics in the right spot makes things easier, but that's not always possible in home-recording. Corrective EQ is cool, high/low pass is like killing an ant hill with a stick of dynamite.
 
upside down hockey stick AB...thats what it is.....


hi and low pass everything...its the way forward!!
 
whoa there!!!!... thats just a little too fucking accurate! :eek:
 
When I'm working on a song that has lots of tracks (almost all of them, lol) then EQ becomes more important so that sounds don't walk all over each other.

A good example is acoustic guitar. In a solo setting, I wouldn't EQ. But in a rock mix, the only thing I'm looking for is the percussive sound of the strings. The low-mids just muddy up the vocal and electric guitar.

When I'm using sounds that occupy the same sonic space - say, for instance, I'm using Rhodes, electric guitar, acoustic guitar, and vocals in a single part - I'll try to EQ so that each sound is intelligible. Otherwise you get a soup of mids.

Background vocals often get a high pass, to give them "air" and set them apart from the lead vocal.

Tons of subtle and approriate ways to use EQ without killing the song. It's just a tool to give ensemble recordings clarity.

And yes, if you are a talented engineer then you can anticipate these types of issues and get your mix in front of the mic. Alas....
 
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