05-31-2011 05:03 AM
Hello,
i have a problem regarding the svx sound write waveform.vi. I try to record some sound with a microfone (max 120dB) via labview. when i reach certain amplitude, the .vi refuses to write and returns a 0-line on the graph. I tested the sound on some other program, and it showed that the amplitude reached max.116dB, and the microphone has max 120dB, why is .vi refusing to write, if i dont even reach the max value? And how to lift that max value so i can reach even more dB for record. No errors are returned, at every stage.
Picture 1 shows the block diagram
Picture 2 shows the result after X seconds of aqusition and recording, when everything is ok, and the max sound presure is about 100dB
Picture 3 shoes the result after X seconds of aquisition, but there is no recording and no time graph, becose the sound is too loud (and it didn't even pass 115dB, and max is 120dB)
05-31-2011 06:47 AM
Please do not post pictures. As we can not debug a picture. Hope undertsand
05-31-2011 06:50 AM
Sorry.
05-31-2011 08:32 AM
Anyone?
05-31-2011 08:41 AM
You are plotting the normalized output of the sound write VI. If you saturate your inputs (which is what you seem to be doing), you will get exactly what you got - zeroes for everything. Try plotting the input to the sound write instead of the normalized output.
You will need to turn the gain down on something if you want to record higher sound pressures.
Also, look at the code in the write sound data VI so you understand what is going on.
Good luck!
06-01-2011 01:21 AM
Yes I tried to plot the input of sound write and it plots all the data, but in different scale. But my point isn't to plot the data, but to write it down, the plot is there, just to see if everything is written, as it supposed to be.
Also i dont see anything in the sound write vi that i could gain down. I should recive real values also at the end, so if you suggest to just scale them different, thats no good for me 😕
06-01-2011 04:57 AM
The "Sound wite.VI" Normalize the data. Use a simple standard binary file for storing your data instead. I guess no soundcard will support a sample rate equal to 50KHz anyway. So no need to use the wav file format anyway