Hello to every body,

I´m trying to make audio measurements with a microphone on a noise machine. After I will analize it with a dsp.

I´m having problems with some noise in low frecuencies.

I would like to find an active high pas filter integrate with tuenable frecuenci fc 200hz for example but with a good order on the filter (like 4 or 8). If it is a band pass filter for audio is also ok.

Many thaks for your help

Aren from Spain

 

Please any help

 

Tunable high order filters are not simple.
Have a look at this article.

 

Are you looking for a circuit to build, or a piece of equipment to buy?

ak

 

Why does the noise need to be filtered before converting to digital? Is is that much larger than the signal? Does it really need to be tuneable?

What frequency is the noise and what is the frequency range of interest?

 

Why not use an audio graphic equaliser, that way you can cut the frequencies you don't want, and boost the one you need.

 

Hi every body, MAny thanks for your effort.

I´m looking for a single component to make a hight pass filter arround 200Hz. It didn´t need to be tuneable.

The Idea is to take only the measurement of frecuencies biguer that 200 HZ. I was making test with some circuits with order 2 of atenuation (12dB/oct) but I need something more like order 4 with 24dB of atenuation or more. I would like to buy a simple IC and make it with some resistors and capacitor on this IC. I would´nt like to make a log schematic for this use.

Best regards and many thanks

Aren

 

google "rumble filter" as used on audio amplifiers to cut the low Hz when using turntables and vinyl records

 

OK. Simple high-pass filter. Two capacitors and two resistors. Only guessing the values here! There is nothing very good about it - but it is simple!