High Pass Q setting?

[moresound]

"The locusts are not a plague as you might think, but a gift from above."

"Once you get past the legs it's not too bad."

OK If you say so Miro I haven't had the pleasure yet but maybe one day I'll get a round to eating me some locust.

 

[miroslav]

A cue from Mr. San Francisco:






...or is it maybe this:







...or this:

 

[miroslav]

Whats the difference between a high pass filter and a shelf set at the same frequency?

I'll butcher the answer...Glen will give it to you textbook.

 

[Chibi Nappa]

Whats the difference between a high pass filter and a shelf set at the same frequency?

A high pass filter MUST attenuate the low frequencies into oblivion. If I put a high pass at 100 Hz, there will be no signal at 30 Hz.

A shelf could just knock it down a few DB. I could put a shelf at 200 Hz and still have plenty of signal down at 20 Hz, just quieter than it was before. You could shelve the low content down into oblivion if you wanted to. Then the shelf would be acting like a high pass.

 

[SouthSIDE Glen]

Whats the difference between a high pass filter and a shelf set at the same frequency?

A HP will cut by more dBs the lower the frequency on a continuous slope downwards. That HP slope is usually expressed as x number of dBs per octave.

A shelf, OTOH will change the curve by a set number of dBs, and then level off and flatten. This looks like a flat "shelf" (hence the name). Note also that a shelf can be a boost or a cut, whereas a HP filter is always a cut.

here's some pretty pictures showing examples of both an HP and a shelf, along with a higher-Q HP showing the bump that can occur at the hinge frequency at higher Q on some EQs:

G.

 

[mixsit]

A high pass filter MUST attenuate the low frequencies into oblivion. If I put a high pass at 100 Hz, there will be no signal at 30 Hz.

A shelf could just knock it down a few DB. I could put a shelf at 200 Hz and still have plenty of signal down at 20 Hz, just quieter than it was before. You could shelve the low content down into oblivion if you wanted to. Then the shelf would be acting like a high pass.

Come on Chibi that was terrible!