Loudspeakers and delay

[DelPiero]

Hello,

I'm trying to create a code that allows me to feed 16 speakers with the same signal but to put a delay between the feeding of these speakers in order to create an acoustic beam steering by this array of loudspeakers. I hope one of you will be able to help me. My searches on the forums and my own codes have not been successful.

Best,

DelPiero

[Yamaeda · Accepted solution]

You should have an array of samples to play for a channel, all you need to do is shift it a number of samples for another speaker, then send both out.

[billko]

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@DelPiero wrote:

Hello,

I'm trying to create a code that allows me to feed 16 speakers with the same signal but to put a delay between the feeding of these speakers in order to create an acoustic beam steering by this array of loudspeakers. I hope one of you will be able to help me. My searches on the forums and my own codes have not been successful.

Best,

DelPiero

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Interesting.  Phased array beam steering, just like we do with RADAR.

[AnalogKid2DigitalMan]

Or acoustic levitation using a couple piezo' s:

https://www.youtube.com/watch?v=669AcEBpdsY

-AK2DM

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[DelPiero]

Thank you for your very clear answer. Only would you have an example of this kind of code please? I apologise in advance but I am far from mastering LabVIEW software. I hope I am not asking too much of you.

[DelPiero]

My project is very much in line with RADAR technology. However, we are trying to understand the deflection of sound waves on contact with a surface.

[billko]

So which part are you having problems with?  You will need to be fairly precise with the placement of the speakers, and the more precise you are, the better your results will be.  It's been literally decades since I've thought seriously about phased array theory and now only have a high level grasp of it.  Hopefully someone here knows more than I remember?

[NIquist]

You are going to need accurate and deterministic timing to manipulate the phase of multiple signals like that. How are you generating your physical signals? A good sound card and windows might get you started but it seems to me you would want simultaneous multi-channel Analog Outs (DAQ Card?) so that you could accurately trigger your waveforms. I did a quick search of NI cards and there's not much that can do more than 4 channels at the 100KHz frequencies you'll "probably" need (I'm not sure how your waveforms are shaped). 

What hardware do you plan to use?

[DelPiero]

Thank you for your reply.

The problem I have is the one concerning the code. I discovered LabVIEW a week ago. The problem that I try to raise is that to feed the 16 speakers and to put a delay between the sending of the acoustic beam of each speaker. In this way, I will be able, by managing the delay, to choose the angle of the global acoustic beam (of the 16 speakers).

DelPiero

[DelPiero]

Thank you also for your answer.

I will use 8 "XH-M543" (Digital Amplifier for Audio Amplifier Board (2-channel, 120 W, TPA3116D2, PCB PA3116D2)) to which I will connect 2 speakers each. These 8 boards will be connected to the terminal block "SCB-68A". Finally, the terminal block will be connected to the computer "NI PXI-1042".

DelPiero