That is quite mild in comparison to her usual Youtube videos (Naomi Wu)
Ok you aren’t kidding. I don’t know why a review of an electric toothbrush needs to be in 360 degree VR, but I’m here for it
I understand it will be hard to get your attention back now but this is the 5-vane version. I'll post DXF later for those willing to actually test it / let Naomi print it for them
(It's actually a 4-vane version, 5 channels.)
(It's actually a 4-vane version, 5 channels.)
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And that's why I said you must be joking. If you draw such lines between on-axis and 90 deg for ANY so called constant directivity device, you will get the same picture (or worse). It's the -6 dB relative to the on-axis what should interest you, i.e. the beamwidth. And as I said, it's too small to keep the beamwidth very low, because for this experiment I didn't want anything too big.
This has NOTHING to do with LeCleach.
- Keeping the beamwidth to a lower frequency is easy and straightforward - simply increase the size of the horn. Keeping it constant at high frequencies is what is difficult. And that's what is the spherical wave plug for - spherical wave doesn't beam.
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Keeping closer to conical for longer does make efficient narrow low frequencies for a given device. Sometimes a little diffraction can even help that along. I usually find rounding lets go earlier, and I don't use small waveguides or horns and I still have a problem.
I guess I'm used to seeing this go hand in hand with a narrow top end. I don't remember beaming to be a real issue until recently, so I'm making that connection.
I guess I'm used to seeing this go hand in hand with a narrow top end. I don't remember beaming to be a real issue until recently, so I'm making that connection.
In fact, and it's a little funny, with the spherical wave as the source we suddenly face the opposite problem - it gets very easily too wide at high frequencies (the beamwidth increases too much). That's the reason you probably won't see it closer to conical. But I have spent only a very limited amount of time on that so far. The optimal shape for the horn is still to be determined. What you see now is just an initial guess that seemed to be good enough.
OK, here we don't agree. Remember your arguments
- This is a BEM simulation of what is aragorus testing (driven with a flat wavefront). To me the question is how close can we get with a real implementation & construction. I don't see a fundamental theoretical problem - wouldn't it show already in the simulations?
I will admit that my comments are based on "intuition" more than any real data, and "intuition" in acoustics is a dangerous thing.
Several things have bothered me along these lines:
1) when vanes were added that are normal to the wavefront, I expected little to happen. Your sims show otherwise. I found that curious.
2) when I felt that the vanes being curved would be a problem, your sims show that it works great.
These two results bother me, although, as I said, I can't prove anything at this point.
The published actual results are what I expected. I will agree that those results could be due to the driver - there is no way to remove the drivers influence in the results.
Should all this turn out to be exactly as you expect then great. I'll just put it down to "intuition" being dangerous in acoustics. Although it could also be that the sims have some limitations. We will see.
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The vanes simply divided the previously continuous volume into several separate pathways of different lengths, so it just couldn't sum coherently any more.
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