octave analysis band power

[fredik]

Hi all,

I have one microphone, cDAQ-9181, NI-9234 module, NI sound and vibration toolkit.

Now I am using the SVT fractional octave analysis for one channel sound signal.

By the way, the octave analysis has the frequency range as input, the total band power as output.

The frequency range(20Hz ~ 20kHz), start frequency is 20Hz and stop frequency is 20kHz.

I want to exclude my unwanted frequencys from the total frequency range(20Hz ~ 20kHz).

After excluding some frequencys from the total frequency range(20Hz ~ 20kHz), I want to get the total band power.

My final purpose is to get the toal band power after excluding some frequencys from the toal frequency range.

If it is impossible, on the other hand, I want to add each band power by including my wanted frequency range.

It can be some frequency ranges.

For example, 300 ~ 500Hz, 900 ~ 1000Hz, 1300 ~ 1500Hz

Can you help me?

[Henrik_Volkers]

If you want to remove single requencies (sine) try the tone detection vi (see help to define the frequency search range) and output the residual wfrm.

However, you can do any manipulation you want directly in the frequency domain 😉

[fredik]

Thank you very much for your reply.

I was late because of my job.

I tried to remove unwanted frequencies as your solution.

In time domain, I tried it by using multitone waveform(1ch) function of "SVFA Extract Tone Information.vi"

In case of low frequencies(125Hz,150Hz), it works normally.

The Amplitude of two low frequencies(125Hz,150Hz), its amplitude decreased by using multitone waveform(1ch) function.

but, in case of high frquencies(800Hz,1250Hz), its amplitude doesn't decreased by using multitone waveform(1ch) function.

Why? I want to know the reason.