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High Pass . . . Low Shelving ?

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High Pass . . . Low Shelving ?

Postby Situation » Wed Apr 25, 2012 12:33 pm

What's the different between a high
pass filter and a low shelving EQ
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Re: High Pass . . . Low Shelving ?

Postby Sam Inglis » Wed Apr 25, 2012 12:36 pm

A high-pass filter progressively eliminates more and more of the frequencies below the cutoff point, whereas a low shelving cut attenuates all frequencies below the cutoff point equally.
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Re: High Pass . . . Low Shelving ?

Postby Situation » Wed Apr 25, 2012 1:17 pm

thanx
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Re: High Pass . . . Low Shelving ?

Postby SafeandSound Mastering » Wed Apr 25, 2012 2:53 pm

Have a little look here:

How to use an EQ

Cheers

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Re: High Pass . . . Low Shelving ?

Postby Hugh Robjohns » Wed Apr 25, 2012 2:59 pm

This image shows the effect of a 3rd order (18dB/octave) high-pass filter with a turnover at 100Hz (green line), and a low shelf cut of -12dB, also set to 100Hz (blue line) on a white noise signal (red line).

Image

As you can see, the high pass filter's slope just goes on down, providing ever-more attenuation as the frequency gets lower, where as the low shelf looks just like a shelf -- it reduces the signal to a set level below the turnover frequency, but no more.

Shelf equalisers can also boost the signal, whereas a filter can only cut.

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Re: High Pass . . . Low Shelving ?

Postby Hugh Robjohns » Wed Apr 25, 2012 3:08 pm

SafeandSound Mastering wrote:Have a little look here:

How to use an EQ

Or you could look here:

SOS EQ Exploration

or here:

SOS Equalisers Explained

or here:

SOS Using Equalisation

or here:

SOS What's the Frequency?

or here:

SOS EQ: How and When To Use it



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Re: High Pass . . . Low Shelving ?

Postby Andi » Thu Apr 26, 2012 9:27 pm

Hugh Robjohns wrote:
SafeandSound Mastering wrote:Have a little look here:

How to use an EQ

Or you could look here:

SOS EQ Exploration

or here:

SOS Equalisers Explained

or here:

SOS Using Equalisation

or here:

SOS What's the Frequency?

or here:

SOS EQ: How and When To Use it



hugh

So I'm getting that this so-called "EQ" stuff is important then?
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Re: High Pass . . . Low Shelving ?

Postby Stef Andrews » Thu Apr 26, 2012 9:55 pm

Andi wrote:
So I'm getting that this so-called "EQ" stuff is important then?

I wouldn't bother with EQ - just cover up any mess with masses of reverb and delay!

However, those articles are all excellent. Well worth the time it takes to read through them!
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