Low pass filter

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Seinbeans
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Joined: Fri Apr 30, 2021 9:44 am
Operating System: Windows 10

Low pass filter

Post by Seinbeans » Fri Apr 30, 2021 9:49 am

Can the low pass filter or high pass filter have a setting higher then 48DB?

steve
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Re: Low pass filter

Post by steve » Fri Apr 30, 2021 10:58 am

You could apply the filter multiple times.
(This is known as "cascading").

If you apply a 12 dB per octave filter to the same sound twice, it is approximately the same as running a 24 dB per octave filter once, (though the transition from passband to stop band will be more gradual with multiple passes).
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)

Trebor
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Joined: Sat Dec 27, 2008 5:22 pm
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Re: Low pass filter

Post by Trebor » Sat May 01, 2021 9:59 am

Seinbeans wrote:
Fri Apr 30, 2021 9:49 am
Can the low pass filter or high pass filter have a setting higher then 48DB?
The free version of TDR Nova has up to 72dB high & low pass filters.
The 32-bit VST2 version of that plugin works in Audacity on Windows.

kozikowski
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Re: Low pass filter

Post by kozikowski » Sat May 01, 2021 10:23 am

have a setting higher then 48DB?
Scientific application, or actual sound? We are warned that "brick wall" filters tend to not sound very good. That's one of the reasons the Audacity built-in ones don't go any higher than they do.

Natural musical sounds usually have a base tone and a bunch of harmonics and overtones.

Image

That's one single piano note, "G1" (49Hz) way over on the left of the keyboard. All the rest of those tones (measured along the bottom) are what make that piano sound like a piano. Some of those tones buck instead of add. If you take them away, tonal distortion may go up. Even worse, you're taking sound away, but the volume of the note may go up.

Koz

steve
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Re: Low pass filter

Post by steve » Sat May 01, 2021 10:31 am

If you need an extremely steep filter, use "Spectral Delete": https://manual.audacityteam.org/man/spe ... elete.html
9/10 questions are answered in the FREQUENTLY ASKED QUESTIONS (FAQ)

kozikowski
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Re: Low pass filter

Post by kozikowski » Sat May 01, 2021 10:53 am

It's possible there are a number of other tools to do what you want. For example the mains hum filter and frying mosquito USB microphone errors. Those are careful surgical deletions and sometimes you can't tell they're running.

Those are both "rescue" tools intended to turn an already recorded show with damage into a successful show, or at least one that's not trash. In all cases it's a good idea to fix the recording problem.

Koz

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