Loudspeaker Frequency Response

[jamison.suade]

Hi all! I'm making a program to measure the frequency response of a loudspeaker. I'll be using a sweep to test the loudspeaker. 

Particularly i would like the program to be like this, which is real time. How can i implement this in LabVIEW. This is the screenshot

Details about the plot.

First graph:

Shows a plot in real-time of a frequency sweep with a constant sine sweep amplitude of 1 V. When sweep is started, the graph shows a plot of FFT moving from left to right, with peak of FFT at maximum amplitude of 1 at corresponding frequency of the sweep.

Second graph:

Shows the plot of the Sound Pressure Level in dB versus freqeuncy.

Please refer to the picture and video link below.

https://www.youtube.com/watch?v=sKC3ioWXG38, skip to 4:10

[SteveD123]

Assuming your idea is to sweep a frequency into an amplifier connected to the loudspeaker, and measure the frequency response with a microphone:

You need to monitor the signal at the loudspeaker terminals to account for any non-linearity's in the signal generator and amplifier.

You need to know the frequency response of the microphone, this is difficult, and that is why calibrated microphones are expensive.

You need an anechoic chamber so that the results are not affected by any room resonances.

Your sound level plot is in dB (A). My understanding of the A weighting is so that the human perceived loudness is constant across the audio frequency range. If you are concerned about loudspeaker performance, is it worth discarding the complexity of this additional frequency response curve?

This will be a difficult project. Please let us know how you get on.

[GerdW]

continued here…

@Gijude: Please stop asking questions with personal messages. Ask your (LabVIEW-related) questions in the forum!