Live strong pass audio filter, with adjustable setting of minimum pass level.
Bad input gives bad output , but there are exeptions when the output result depends on human hearing. Our
ears are not sensitive to volume change. 3dB is the absolute
minimum audio volume difference we can hear. that equals to Signal voltage x 2 or /2 , using a
By using our real time strong pass audio
filter to eliminate background noise, all signals smaller than the minimun pass level adjusted by the user, are reduced by
a factor, typical 20dB . You can clearly hear that noise reduction.
This will also result in some small
audio volume errors, but just that is not a problem.
Our ears are not designed to hear it.
Idea & solution by Joar Falstad.
The weakest parts of the total signal, smaller than the preset minimum
pass level, are redused by a factor.
Up to 100x or -20db reduction
is used in our filter . No audio signal delay. Tone balance, max volume and pitch are not changed in any way. Only the disturbing background noise has almost vanished.
The result is natural sound .
Developement use only.
Line in / out signal in consumer equipment has a standard max value : 0.316 Vrms
Tape / Aux signals are often close to line signals.
Our strong pass audio filter input / output audio signals max value : 4Vrms
Galvanic insulated transformer output.
normal voice . noise reduction Video
realistic audio background noise reduction
Measured audio volume reduction outside pass level : up to 100x or - 20db . Suitable in / future suggestions : chipcorders , hiss and background
noise reduction / removal / cleaner / limiter
Hearing aid systems , stage monitors, PA systems : background / ambient noise reduction .
If the noise is bad the audio transformation
is not perfect,
but what is important , your ears will hear it as an improvement .
More video's to come , to show how to set the minimum pass level
controller . Different audio noiselevels.
Live audio background noise reduction or removal , hiss cleaner , minimum signal filter
One channel prototype item.
Line in - out balanced , 600 ohm impedance.
Aux in unbalanced, high impedance.
Easy adjustment : A LED.indicator for visual control of the strong pass filter. And for best noise cleaning
result, an adjustable controller to set minimum pass level .