"It's not irrelevant: it's a hippopotamus!"
"His inamorata adjusted her garter, and lifted her voice in duet"
You probably have to actually be British to create this stuff.
Always,
Chris
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"Alcohol, taken in sufficient quantities, may produce all the effects of drunkenness. - Oscar Wilde "
"Have some Madeira, m'dear."
All the best,
Chris
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Me?
Yes, I have 3 pistonphones and a brace of B&K mikes and AC calibrators etc. I was not aware of the temperature sensitivity of the Panasonic type microphones. Is that documented anywhere? I believe there are some that are less sensitive to temperature. I know MEMs mikes are better for temperature and absolute sensitivity. Not so good for noise floor.
The Radio Shack meter's I have checked in the past were pretty accurate, usually within a dB. You need to check them at 1 KHz (can't use a pistonphone, they run at 250 Hz) because of the a or c weighting. As I remember the ballistics were on target as well (Checked with a GR Omnical). For checking annoyances they are pretty good. For research or real measurements not so useful.
Except for inconviencence using a PC with appropriate software will give an enormous amount of info on average, peak and spectral content of sound. I have an NTI Audiolyzer that can do most of that and is handheld.
However pulling out something that looks like a recorder at a concert is not usually a good idea.
There are free apps and low cost apps for general purpose acoustic measurements (room/speakers etc) that use the iTOUCH. You can also plug in an electret mic and have a cheap portable unit which includes RTA, SPL, Freq Response, scope, FFT, signal/speaker polarity, frequency measurement, accelerometer and other basic measurements. Accurate enough for most work. Not a laboratory standard. But much much better than just a R-S SLM and just as compact and portable.
The other fluff, like camera, wifi and music are a bonus 🙂
THx-RNMarsh
The other fluff, like camera, wifi and music are a bonus 🙂
THx-RNMarsh
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@Max Headroom
But Dan, that was 8 years ago. In those days, your choice boiled down to whether you wanted an analog scale or a digital readout.
Times change, don't they?
But Dan, that was 8 years ago. In those days, your choice boiled down to whether you wanted an analog scale or a digital readout.
Times change, don't they?
Maybe enough time has passed now for thermionic indicators like EM84, EM11 or 6G5 Vu indicators to be in vogue ? I always did like them.....
EM84 video
I have probably a dozen, waiting for that rainy day.
EM84 video
I have probably a dozen, waiting for that rainy day.
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Just finished posting a lot of test files to support Scott Wurcer's digital RIAA article in L|A Vol 10, here: Downloads | Linear Audio
The post also has the complete collection of the coefficient tables for anyone who wants to experiment with digital RIAA on your miniDSP, so you can just cut-'n-paste rather than typing it all up.... Note that one of the tables was missing from the printed issue, apologies to Scott!
Jan
The post also has the complete collection of the coefficient tables for anyone who wants to experiment with digital RIAA on your miniDSP, so you can just cut-'n-paste rather than typing it all up.... Note that one of the tables was missing from the printed issue, apologies to Scott!
Jan
How much better and why? An uncalibrated microphone is still an uncalibrated microphone whatever you plug it into.
Just checked the $75 Umik-1 and even though that comes with a cal file, thats just for FR flatness not absolute level as far as I can tell in the specs, Noise floor is no great shakes either but that was not what I wanted it for.
The instantaneous fuel consumption display is educational.
There is also a data logging upload to PC function of user chosen parameters.
Dan.
I have only ever had dial gauges.
Yeah, it's cool, way cool.
Scroll through the screenshots on the Torque Pro Android app page.
The screenshots give scant idea of the customizeable display pages that can be configured and only a fraction of the engine and other parameters that are available as analogue dial, digital, bar, graph etc in a bunch of sizes.
For only a few dollars I highly recommend it.
Dan.
well can educate you that staring at s a smart phone whilst driving is really really dumb.
Looking at gas composition of exhaust in real time is educational as modern sensors are >>faster that the actual cycles.
Looking at gas composition of exhaust in real time is educational as modern sensors are >>faster that the actual cycles.
been done, cadillac night vision dodad and some chevvys in the late 90s.
Even F1 dumped them.
Even F1 dumped them.
Why not? I think it would be cool. 😀
Besides, knowing what it's like being up close as the rest of the orchestra, and being among even the singers themselves, to see what it would be like? Cool. Maybe not all the time though... 😀
I had a dog and pony show some years back at a new outdoor concert venue. The neighbors want to be sure they wouldn't hear too much. I had two sound level meters. One a Bruel and Kjaer the other a moderate cost ($150) import. Before beginning I took out a calibrator to show the meters were accurate. The cheaply that had been adjusted hours before was now warmer and off by quite a bit. First time I ever had a meter that really drifted!
Now normal practice is to start any measurement session with a calibration test. Every other time my meters are within 1 dB and usually 1/2!
Now why do you have three pistonphones? They never break the only failure mode is to leave the batteries in them until they leak. Of course the worst failure mode is opening them to see what is inside.
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On an older subject, the issue of super cap or batteries, seems super caps may have the advantage. Noise from either is not the critical factor.
Lithium ion batteries require precise charging of each cell. Over charge and they fail. Super caps can use a simple resistive or diode divider to balance the charge.
Lithium ion batteries require precise charging of each cell. Over charge and they fail. Super caps can use a simple resistive or diode divider to balance the charge.
That's cool. I could do something like that with all my EM84s in one go I suppose...........
I think what people are seeing in not only the cheaper sound level meters as ES has shown of drifting measurements, that this also holds true with cheap microphones, a simple mechanical phenomena. The actual diaphragms are made of a simple plastic membrane, the plastic has mechanical properties that change with temperature, the flexural modulus and tensile strength will vary with temperature. I would think that all the calibration measurements would be taken normally at a set room temperature reading, once you either go to a higher or lower temperature this will change. How much it will change will depend on many factors. The type of plastic, thickness, diameter and the original tension applied to the film and other factors such as this. This is the reason that a microphone such as the B&K microphones will always have much more consistent and accurate measured result, the diaphragm material is a nickel foil which would have much more stable physical properties over a wider temperature range. There is nothing wrong inherently with the plastic film microphones but they will have real materials property that causes this drift, it is caused by both temperature and humidity levels.
I'm sure that Sy can add to this discussion of materials properties of typical Mylar film property changes with these two simple factors, temp and absolute humidity.
I'm sure that Sy can add to this discussion of materials properties of typical Mylar film property changes with these two simple factors, temp and absolute humidity.
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