Voice recorder filter, I am not sure what I should set my passband ripple to.

Thread Starter

mhoga26

Joined May 31, 2021
1
Most often the pass band is considered to extend to the −3 dB point.
I cant find much online about what I should set my passband ripple to for a voice recorder. The lecturer said I should be able to find info online, but I cant. Can you guys save me?
 
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LowQCab

Joined Nov 6, 2012
588
Sorta-Semi- in the range of- 300 to 3000,= Old Telephone,
better intelligibility is 100 to 8000hz, 12db-per Octave.
Super-Sharp cuts are usually not necessary, use a Butterworth Filter.
A Butterworth Filter has very little to zero Ripple.

If you are seriously Bandwidth-Limited, then you may want to consider sharper roll-offs,
but they can be accomplished with multiple-stages, without much cumulative Ripple.

Digital-Filtering may be MUCH steeper, (if necessary), and with virtually zero Ripple.

Ripple is generally the side-effect of trying to get the steepest roll-offs with the fewest parts.
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crutschow

Joined Mar 14, 2008
27,243
For music, you generally want low or zero ripple (such as a Butterworth filter gives).
For voice, some ripple may be allowed (such as from a Chebyshev filter), but how much ripple depends on the system requirements.
 

Audioguru again

Joined Oct 21, 2019
3,208
Some people say voice frequencies are from 300Hz to 3kHz. But that is only for vowels spoken by a little kid or a chipmunk.
The most common phrase spoken on an old telephone is "What? What did you say?" (Waa? Waa id oo ay?).
Most adult males have a voice down to 75Hz and important consonants and sibilants such as s, t, sh, th etc. reach 14kHz.
 

LowQCab

Joined Nov 6, 2012
588
Some people say voice frequencies are from 300Hz to 3kHz. But that is only for vowels spoken by a little kid or a chipmunk.
The most common phrase spoken on an old telephone is "What? What did you say?" (Waa? Waa id oo ay?).
Most adult males have a voice down to 75Hz and important consonants and sibilants such as s, t, sh, th etc. reach 14kHz.
That's why Telephones suck.
But it allows them to put thousands of conversations on one line.
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