Help on NI Speedy-33 (2 questions)

[BK Lian]

Yup, DSP module does have the FFT Spectral measurement but not the bundle function... 😞

By the way, what is the array of numbers (what does it mean) added to the magnitude (after FFT) and wat's is the purpose for the bundle and unbundle?

Thanks-in advance!

[Coq_Rouge]

OK so the DSP toolkit do have a FFT function. So far so good. Does this function have a standard Labview equivalent ? Your problem is how to scale the output. Can you post any documentation?

[BK Lian]

Hmm.. I'm getting very confused.  What documentation r u refering to? The FFT express VI in DSP module is exactly the same that you have shown.

Firstly, a frequency spectrum of the signal is performed (to simpify things, the FFT spectral measurement vi is used)

Secondly, due to the complexity of bilinear transform, A-weighted filter in frequency domain is applied according to the formula posted.

Hence, how do I apply it? From ur example VI, I cant  see the amplitude being attenuated by varying the input frequency...

Thanks!

[Coq_Rouge]

skip the bundeling operation. just add the array constant directly to DSP spectrum output.

[BK Lian]

How did you work out the array of constant with a size of 11025? From the formula?

By the way, is there a convolution in the formula?

[i duno]

hey

BK could you please help me in this field, umm my task is to design spl meter using speedy 33 kit, it seems as u have done some work on it,, please let me know if u can or anyother person can help me out of it.

Thanking all of u in advance 🙂