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Take a look at delta pick and place machines. If the thing you are moving is very light, the delta machines are unbelievable simple and they scale easily to very large sizes. Every axis is identical. There are a lot of hobbyists going this route for large 3D printers and so there's a fair bit of...

Hi @Dave Zan MEMS are all omni. Invensense has a plot in their beamforming document (see fig 2 in the link below). The final mechanics has a much larger impact on the pattern, of course > The TDK in your second link is low noise but much worse frequency response compared to the AD devices...

Hi Dave, these impressive noise levels have been pretty common now for years in MEMS mics. Link 1 is digital TDM MEMS mic with 88 dB DR and 65 dB SNR, noise floor of -91 dB FS (20K bw A weighting) and AOP of 117 dB (10% THD). Link 2 is an analog MEMS mic with 105 dB DR (!!!) and 67 dB SNR...

No, they can be quite good and they have to be because Amazon et al are trying trying to do speech recognition from across the room. The noise floor on modern MEMS is around 30 dBA or -105 dBV. And if you are testing at 90 to 100 dBSPL, there should be plenty of SNR.

Does the math require only two radii are used? Or could the system still be solved if you had a point cloud of measurements, each at a different radius?

Hi Hayabusa, yes, there's a word clock to ensure that all mics start sampling at the same instant. In that mode you need to inhale the 64 channels of mic data simultaneously (64 data bits). But that's no problem for an FPGA. The folks doing mic arrays/beamforming/etc have driven the requirements...

NTK this is impressive what you've published here. You might consider a semicircle of MEMS mics to eliminate the need for a vertical axis and mic positioning axis (if needed). What has happened in the last 5-7 years around digital MEMS mics is nothing short of amazing, IMO. The demand from...

Hi Dana, with the QA401 app (written in C#), the API interface is DotNet remoting. It's really easy if you are writing in managed C++, C# or VB. But if you are writing in a language not inside the MSFT "managed" languages bubble, then it's not so easy. Now, LabView has the ability to load a...

Yes, true, but for better or worse that ship has sailed long ago. The days of a menu item for each settings have given way into grouped sea of controls, with mouse wheel playing a big role in selection and actuation. Take a look at the video below on how scroll wheels get used on ProTools. This...

>> Hi Matt. Of course, just ask. Awesome and thanks! Some notes/observations from various comments in the thread: > I am not a fan...The rotary controls for example show no values. Yes, agree it could be better. But it's not without precedent as this is true for modern desktop scopes too...

Hi @Amir, thanks for the analysis! I'm scratching my head a bit on the measurement with -60 dBr (relative to 2V) because that noise floor seems lower than if input was shorted. But I can report back in 24-48 hours. Is there a chance you could make another measurement if I had a clear request...

Yes, agree, the ability to warp the spectrum would be very useful too. I just posted a new thread in case anyone wants to try and report their results. https://www.audiosciencereview.com/forum/index.php?threads/qa_abx-test-results.8210/#post-204202

This is a continuation of the post here. I hope some others can give a try and share results here as I think it's very important to find those that can demonstrate unique skill in this area. I'm using source material from LessLoss--the 24-bit/96k version of Mephisto Waltz Excerpt #1. You might...

Agree. There is a tool I helped worked on a few years ago located here. The tool allows you to start with a reference wav file of your choice, and then it will introduce different types of distortion on-the-fly (crossover, bit depth, amplitude, clipping, TANH). You can set the intensity of each...

Looks like it went out on April 19. Amir has explained he has a lot of stuff in the queue, which I completely understand.

Yes, I think Denon is quoting their max power at 10% distortion based on Amir's measurement and I've attached TI's plot on the TPA3255. This is from the front page of the TPA3255 spec. They call this a "315W stereo...Ultra-HD" class D part. The 315W into 4 ohms is at 10%--they don't try to hide...

Yes, OK, agree in that case. But most marketing folks are specifying max power well up the right side of the curve. The plot you included is claimed to be a 105W amp into 8 ohms which looks like 10% distortion assuming this plot is into 8 ohms. That's about where all the silicon vendors are...

I don't think that is true. SINAD is simply the reciprocal of THD+N (eg -105 THD+N = 105 dB SINAD). And as you know, the THD+N versus power curve has 3 distinct regions: Noise limited, optimum and harmonic limited. The best THD+N and SINAD will always come from the optimum region which is far...

Awesome, and no rush. It should go out this week.

Yes, agree, edechamps, the N+D is the correct way to look at this. I've attached the N+D plots for both the AK5397 and AK4490. On the QA401, both ADC and DAC are 0 dBFS @ = +6 dBV, so if you connect in loopback, and then drive to 0 dBFS, then both are at the same point of operation, which would...