Whats the use of filters??

[doclegion]

I know this might be a dumb question to some (sorry) but i just want to know about HP and LP fiters and there purpose?
When do i use them??
How do i use them??
Where do i put them?? ETC ETC

any comments would help Thanks guys

 

[Torniojaws]

HPF = allows all high frequencies above the Hz you specify to be heard, and all frequencies below the Hz you set are removed
LPF = allows all low frequencies below the Hz you specify to be heard, and all frequencies above the Hz you set are removed

The purpose is mainly to allow for more room in the mix and to remove extra (unwanted) noise.

HPF is generally set for everything, except for bass guitar and kick drum (sometimes on them). It allows them to have their own space in the mix. A general HPF is at 100 Hz or above. You can also use it to remove kick/snare bleed from the overhead track by setting it to 500 Hz or so.

LPF is often set to either tame shrill frequencies or otherwise control the extra high frequencies of instruments. For example, a guitar cab really doesn't output any information above 12 kHz, so you simply set a LPF at around 12 kHz on ALL guitar tracks. The same principle applies for all instruments.

 

[Keiffer]

a bit more on filters...

there are two terms you should become familiar with

cut-off - defined as the frequency where the gain is down 3db

slope - 6, 12, 24 db/octave

that is, if you set a hi-pass filter to 60 Hz, then at 60 Hz the gain is down 3db with gain decreasing at 6 or 12 or 24 db/octave below 60hz... based on filter design. a take away from this is that the gain actually starts to decrease well in advance of the cut-off frequency and the frequencies in the cut-off region are not all gone but decrease at a specified rate.

I have left out how Q (and damping) affects the filter.

 

[Damian B]

What are some good free plugins to HP and LP with?

 

[Sinister Mephisto]

Almost all EQ plugins have a HP/LP option, including stock DAW EQs.

 

[doclegion]

Thanks guys I always read about them but always unsure on what to use them for and when

Thanks

 

[Fabbio]

Well, since I too learned some new things in this thread I extend the question:
what about the 'shelf' option in most EQ plug-ins?

Does it enhance the frequency indicated without cutting the rest?

 

[PhilR]

Shelf filtering cuts a flat range of frequencies from a given point. For example, a high-pass filter will completely roll off all frequencies beneath a given point, a shelving filter will simply cut (or boost) them by a chosen amount.

 

[PhilR]

http://en.wikipedia.org/wiki/Equalization

Start here, read on.

 

[ahjteam]

btw, as we are all here to learn and as I mainly don't do electronic music, but I've seen this "resonance" on some cutoff filters, any idea what it does? I definately hear that it does something to the sound, but can anyone explain it to me?

 

[Torniojaws]

Resonance effect originates from an artifact in the original cutoff filter used in old hardware synthesizers. It is narrow band of frequencies, near the cutoff level, where the sound is amplified. Today this artifact can be easily avoided, but it is still available though, because it can be used as a special effect. Changes in the cutoff level together with high resonance produces interesting phaser-like effect, which is one of the reasons for the popularity of the TB-303 synthesizer.

http://flstudio.image-line.com/help/html/glossary_cutres.htm

 

[Machinated]

Filters are really cool if you automate them to move about - can make some interesting sounds

 

[Torniojaws]

Filters are really cool if you automate them to move about - can make some interesting sounds

There's a name for it too: wah

 

[Machinated]

There's a name for it too: wah

I do stuff with filters that a wah can't do.....granted it can be a similar concept .

I program EQ's and filters to do all kinds of stuff if the song needs something crazy in it.

 

[digitalmikey]

Great thread. I too was curious about the HP and LP filtering.