Measuring a speaker with a drone

[pierre]

Idea of the day:

use a drone to turn around the speaker and do measurements (instead of turntable etc...)
- noise of the drone is easy to measure and then to remove from the measurement.
- positionning is also relatively easy with existing open source software.
- I am looking for a drone which either has a microphone or is big enough to carrie one. The cheaper the better. Ideas?

Crazy or doable?

Some refs:
- https://www.ncbi.nlm.nih.gov/pmc/ar...m is expected to be,ego-noise and other noise.

 

[pozz]

Doable/testable. Main issues that come to mind are drone stability and consistency during the flight path (averaging may help here), ability to carry a microphone and not tangle up the cable. And expense, of course.

What would the flight path be? 360° polars at set intervals? A slowly descending spiral? Vertical lines at set intervals?

 

[pierre]

Doable/testable. Main issues that come to mind are drone stability and consistency during the flight path (averaging may help here), ability to carry a microphone and not tangle up the cable. And expense, of course.

What would the flight path be? 360° polars at set intervals? A slowly descending spiral? Vertical lines at set intervals?

I had in mind to add a rasperry to the drone and store the measurement on the rpi (or stream them over wifi).
For a spinorama i only need 36 horizontals and same vertically but i will need a lot more if I want to estimate the field (ala Klippel).

I will ask in a drone forum if people have advices.

 

[SIY]

- noise of the drone is easy to measure and then to remove from the measurement.

I suspect this is not easy.

 

[pozz]

I suspect this is not easy.

Same, but worth trying nonetheless.

 

[Speedskater]

A big part of loudspeaker measurements is repeatable accurate placement and alignment of the microphone.

 

[pierre]

A big part of loudspeaker measurements is repeatable accurate placement and alignment of the microphone.

Which level of accuracy is required. Is +/-1mm and +/- 1 deg enough?

 

[FrantzM]

Hi

I hope this is not taken as "crapping on the thread" but ... That seems to me an overly complex solution. A bit of Rube Goldberg.

A turntable is very easy to make and to control. Same with the height of the microphone and its distance to the speaker. Those can accurate to the micron, very cheaply and easily...
Thus why the drone? And its noise and its positioning and its recharging and ... its automation and its cost so that it can carry a microphone, and cabling of said microphone to the measuring device and its precise pointing toward the speaker and the adjustments and stabilizing ... and ... and ...

 

[pierre]

Hi

I hope this is not taken as "crapping on the thread" but ... That seems to me an overly complex solution. A bit of Rube Goldberg.

A turntable is very easy to make and to control. Same with the height of the microphone and its distance to the speaker. Those can accurate to the micron, very cheaply and easily...
Thus why the drone? And its noise and its positioning and its recharging and ... its automation and its cost so that it can carry a microphone, and cabling of said microphone to the measuring device and its precise pointing toward the speaker and the adjustments and stabilizing ... and ... and ...

My motivation is that a turntable is easy to do the horizontal measurements. If you want a sphere view, then it is a lot more tricky.

 

[Instrumental]

If you tilt your proposed setup 90 degrees on it's side you have a wind speed measurement
device and there is lots of windspeed under a drone. Lots of turbulence too. The worst
place for a microphone really. Ultrasound is used in meterology instruments looking
exactly like this.

Spherical movement it easier than linear, only two axels are necessary that are easy to
get stable and precise and to drive with stepper motors. I have used similar setups
to test and measure microwave antenna directional patterns.