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Post by ChrisK on Mar 4, 2009 14:12:50 GMT -5
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Post by newey on Mar 4, 2009 19:42:37 GMT -5
This is fascinating. I began reading the article thinking this was going to be more in the vein of a theoretical discussion, but they actually got what seem to be fairly musical sounds out of this! Although they lost me at "femtofarads". The authors state: But they never discuss what the actual output of this device in fact is, and they don't tell us what they did with the signal thereafter. Nor do we know what was done with the piezo pickup- there are onboard controls on a Stratacoustic, I believe. Likewise the MEMS mic used as a "reference", where did it go from there? I understand this was more of a feasibility study than a controlled A/B/C comparison, but we're missing info on a lot of variables. Can this signal, in fact, go straight in to a mic pre? No boosting or buffering required? The two downsides mentioned are noise floor, which should be solvable with an appropriate gate, and the fact that it doesn't go up to 20KHz. Perhaps more suitable, with present technology, to bass applications? More to the point: Are these things available to Joe Experimenter, or is it Unobtainium? Would this work on a solid body? Apparently, the "triaxial" output of this can be individually mixed, so it'll need X, Y and Z knobs.  |
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Post by ChrisK on Mar 4, 2009 21:06:00 GMT -5
Perchance 10 -15 Farads? Perchance 10 -18 Farads? Ah, grasshopper, one must learn to click on the blue linky thingy(s). www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl330/products/product.htmlDang, analogue outputs. Ah, grasshopper, one must learn to read the data sheets that magically come from one clicking on the blue linky thingy(s). This appears to be a resonance, it may be the sensing mass, it may be the package mass, and/or it may be an artifact of many things. From the magical webosphere, in the cloud called digi-key, one finds the eval board for a unit; search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=EVAL-ADXL335Z-NDand linkaronies to parts search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1966355&keywords=ADXL335It will, of course, pick up the coupled acoustic vibrations. Whether one likes them or not may well be a personal thing. Well, with flexibility comes responsibility. [Luke, use the links, Luke.] |
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Post by newey on Mar 4, 2009 22:36:14 GMT -5
Dang, glossed right over the link! I see $40 for the eval board, not too outrageous. Wouldn't you also get a signal merely by moving the guitar body around? And, I'm maybe missing something basic here, but the authors are talking about bandwidth to 6 kHz on the X and Y axes, and to 1 kHz on the Z axis. But the data sheet in the link talks about it being adjustable up to 1500 Hz on X and Y, and to only 550 Hz on Z. Seems like someone's off by several orders of magnitude . . .  |
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Post by ChrisK on Mar 5, 2009 12:03:29 GMT -5
Indeed!
However, to generate a signals that the amp might even begin to care about, one would have to sustain frenetic/frantic gyro-osculations on the order of 20 - 40 Hz. I suspect that that would quickly put the gyrator in a world of Hertz.
Of course, aside from the unfortunate fact that the sensor actually exists, the air guitar crowd (well, bunch) might find this of interest aside from the unfortunate fact that the sensor actually exists.
Don't confuse sensor bandwidth with a particular implementation's adjustment range. It's like confusing cost and price. Price is what the market is willing to bear. Cost is what you're willing to bear.
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Post by Teleblooz on Mar 5, 2009 17:08:44 GMT -5
I suspect that that would quickly put the gyrator in a world of Hertz. <GROAN>  |
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