VO-BB - 20 YEARS OLD!

[Rob Ellis]

I'm experimenting with the High Pass function in my recording software.

What's a typical amount of db per octave when configuring these settings?

I've seen 12 db mentioned, just wondering .....

[Lance Blair]

On my graphic EQ on AA3 I do it like this:

80Hz - leave it alone.
63Hz - bring it down -6db
50Hz - Crush it to nothingness (expand the scale to like 120db first)
40Hz - Crush it to nothingness
20Hz - Crush it to nothingness

I consider this "taking out the trash" and the real tailoring of the sound on that end comes from dealing with 200 and or 500 Hz for example (depends on your room, voice, etc.)
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[Mike Sommer]

What Hipass filter are you using?
What are you trying to use it for?

A few screen shots would be helpful.

The only reason I use a Hipass filter is to "Cut" the low frequencies below 75Hz. In this capacity it could be called a low-cut filter or bass-cut filter.

What Lance is describing is a roll-off (more or less):


This Hipass filter shows a low frequency cut.

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Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.

[Rob Ellis]

I'm using the High Pass function in Amadeus Pro.

Just experimenting with it and comparing it with using the High Pass on the Avalon 737.

In Amadeus, the application looks almost exactly like your second screen shot, Mike.

But if it's set at 0 db, does that achieve anything?

[Mike Sommer]

NOTE: The following description is for the AU Hipass filter. Your milage may vary.

The top slider adjusts the filter's cutoff frequency between 10 Hz and 22 kHz.
All frequencies below the setting are cut in volume. In the first chart below you'll see
it's actually more of a downward slope at about 12dB per octave.

The bottom slider adjusts the filter's resonance from −20 dB to +40 dB.
It allows you to adjust the frequencies at the cutoff frequency; thusly allowing you to give an
"edge" to the filtered sound.
For our intended use we don't need it. Leave it at zero.

This image shows a 200Hz with no resonance.


This image shows a 200Hz with +20dB resonance. (Positive resonance adds a sharp
upward point at the cutoff frequency.)


This image shows a 200Hz with -20dB resonance. (Negative resonance cuts the volume at the
cutoff frequency, adding to the filter's normal downward slope to create a longer, more gradual
slope. This causes the filter to affect frequencies several octaves higher than the cutoff frequency.)


The Avalon Hipass has stepped cuts: 30, 35, 40, 45, 55, 60, 70, 80, 100, 120, 140 Hz respectively.

This is convenient, especially if you are using the onboard compressor, and that is only the reason I would use it.
_________________
The Blog:
http://voiceoveraudio.blogspot.com/

Acoustics are counter-intuitive. If one thing is certain about acoustics, it is that if anything seems obvious it is probably wrong.