Using a spectrum analyzer app to analyze the sound to determine exact RPMs of various tools, also bandsaw blade speed.



  1. Interestingly enough, this is the same method I use when making cooked chocolate pudding. Mind you it does not work for vanilla or tapioca.

  2. Would it be possible to reduce the noise level of tools locally with baffles and absorption to negate need for hearing protection?

  3. Summary : here is another reason why iPhone is for people who only buy it to show they have an expensive phone XD but don't know much about all its features compared with the unlimited host of android options that are more value for money

  4. Fantastic video, like always. But this video, just like many other videos of yours, makes me feel unintelligent. Now I have to spend my next weekend playing with this app around my shop until I figure it out…..
    It's videos like this that justify you having almost 1.3 Million subscribers.

  5. Another interesting method for detecting frequencies is with with an instrument called a sirometer. It's placed on the motor and a wire protrudes out. When the wire oscillates the most, the dial indicates the rpm and frequency.

  6. Cool video! I'm a fan of "Physics toolbox", an Android set of apps, that has an audio spectrum analyzer among a few other things- accelerometer data, gyroscope data, basically all of the sensors on your phone. I used it to measure the acceleration rate of a servo motor with a much heavier load on it than normal at work (mechanical engineer) and it turned out way better than our standard method of differentiating a potentiometer or encoder signal.

  7. I would think the fan should slow down when you remove the filter, as it would be moving considerably more air.
    It should be drawing the most power when it’s moving the most air.

  8. I'm imagining AvE giggled like a schoolgirl when this went up. Very cool! I imagine the ability to estimate how close to full-load a motor is would be extremely useful when building stuff.

  9. I didn't quite understand any of this until you showed the difference between fan with filter and fan without filter in real time. Nice video.

  10. Perfect timing. I was just thinking that "listening" to the frequency changes of my shop vac
    with and without my shop built separator might be a rough way to measure impact of adding the separator.

  11. Sorry, this just looks like unsolicited commercial video (UCV). So long, and thanks for all the fish. Unsub.
    There's just too many SA apps out there w/ features way better than your promoted one, even w/o paying a single buck they let you zoom in (and — yeeehaa — even out), and much more.

  12. Awesome video and explanation. Engineering explained from a practical point of view. I love this kind of videos. Thank you, Matthias.

  13. I'm an audio guy and use sound analyser for my android phone which also has waterfall plots and other advanced features. I'm pretty sure it's free. Great video as usual! You know… I've made several acoustic panels and have wondered how you would do it. The material used for absorption was 2×4 mineral wool panels 2" thick. I built a basic pine frame around them and stapled black felt liner to it. Another thing I've been wanting to build is a diffusion gradient to scatter target acoustic wave ranges in my recording studio. I think you would love tweaking and researching the application. There's free software called qrdude which calculates blade/block heights to construct 2d and 3d panels. These can be glued, fastened, or modeled based on how complex you want to make the thing. Some of them on the web are quite beautiful in their precision and assembly. I've been wanting to do/see a good video on building acoustic treatments like these.

  14. As usual Matthias your knowledge far outweighs my understanding. I follow in awe of what is out there. My limited experience in electronics falls down to fitting plugs to tools. But I'm always willing to learn more, my personal limited lifespan only allows a few more years to take it all in. I'm pleased there are those like yourself willing to impart your knowledge to others. Thank you

  15. I’m sure this has already been stated but what do you do for a career? I was surprised to see this because I am a vibration analyst. I thought it was a very good explanation of Hz in relationship to rpm. Great job!

  16. The 120Hz offset peaks are probably amplitude modulation caused by the rectifier bridges, since high-RPM tools use DC motores. AC motors can only go as high as the line/grid frequency (3600RPM at 60Hz).


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