Real-Time Data Filter

Hi all, hope you are well.

I'm trying to find a way to add a frequency dependent correction to a microphone channel during data acquisition (or alternatively following acquisition, before post-processing). Something similar to the curve below:

I originally thought this could potentially done via the microphone correction module, but I've had no luck with that.

I've since been trying to do this using the frequency-dependent filter module, which seems like it might be possible - however I can only boost specific frequencies with that module (as the Magnitude column will not allow negative values).

Just wondering if anyone has any experience in this, or has any other suggestions?

Thanks in advance!

@Andy Todd

Thank you for your question. The Magnitude column values represent factors by which the actual measured sound pressure will be amplified, not the relative sound pressure in dB. From the equation for relative sound pressure in dB, which states that:

relative_sound_pressure [dB] = 20*log(measured_sound_pressure / reference_sound_pressure)

in which we substitute measured_sound_pressure for amplified sound pressure, which is:

amplified_sound_pressure = Magnitude * measured_sound_pressure

we can calculate the Magnitude as 10^(relative_sound_pressure [dB] / 20). You can then calculate the Magnitude values using Python or a Microsoft Excel spreadsheet as shown in the attached image. After that you enter the calculated values in the Custom filter table in the Frequency domain filter setup.

We have also informed our software development team about the feature request where you would be able to enter gain values in dB directly and not have to perform the previous calculation. If you have any further questions feel free to post them.

Kind regards,

Vitjan Lin Zupan

Customer support