hi people,
I am working on the design of an audio compressor, and I want to automate level in/level out measurements. I have an AP that I use for most bench work, but unfortunately it doesn't sweep level vs. level.
I could do this quite well enough using a PC and a soundcard (I don't care much about distortion/noise), but how to do it? I seem to remember a long time back I came across open source audio test software that people were using, but I don't find it back now. Don't remember the name.
Does anyone have an idea for software tools that will do this out of the box,or with some hacking?
To clarify, what I want to do is a mono test, all at one frequency. Simply increase the generator in (say) 1dB steps, pause to allow settling time, and then measure the level of the circuit output, in dB. Absolute values not important, I can calibrate these externally.
Then get the results either as an on-screen graph, or in text format that can be processed and pulled into a spreadsheet.
thanks!
Daniel
I am working on the design of an audio compressor, and I want to automate level in/level out measurements. I have an AP that I use for most bench work, but unfortunately it doesn't sweep level vs. level.
I could do this quite well enough using a PC and a soundcard (I don't care much about distortion/noise), but how to do it? I seem to remember a long time back I came across open source audio test software that people were using, but I don't find it back now. Don't remember the name.
Does anyone have an idea for software tools that will do this out of the box,or with some hacking?
To clarify, what I want to do is a mono test, all at one frequency. Simply increase the generator in (say) 1dB steps, pause to allow settling time, and then measure the level of the circuit output, in dB. Absolute values not important, I can calibrate these externally.
Then get the results either as an on-screen graph, or in text format that can be processed and pulled into a spreadsheet.
thanks!
Daniel
I suspect that you could generate a file with the test tones you desire in Audacity, and then use Audacity to measure a file you recorded by looping through the UUT. Audacity is freeware, multi-platform, and I think it even has a scripting language.
hi Arnyk,
That doesn't really do it. Of course I could record any test sequence I want using any audio program and play it back, but that doesn't analyse the circuit output in terms of dB's, and give the result as either text or graphical output. For that some other kind of software is needed.
I am quite sure that a year or two back I was looking at some kind of open source software that seemed to do quite comprehensive audio testing via a soundcard. I just don't remember what it was called. It seemed to have a fairly decent user base though. I hoped someone might have pointers on that.
Thanks anyhow.
That doesn't really do it. Of course I could record any test sequence I want using any audio program and play it back, but that doesn't analyse the circuit output in terms of dB's, and give the result as either text or graphical output. For that some other kind of software is needed.
I am quite sure that a year or two back I was looking at some kind of open source software that seemed to do quite comprehensive audio testing via a soundcard. I just don't remember what it was called. It seemed to have a fairly decent user base though. I hoped someone might have pointers on that.
Thanks anyhow.
You aren't giving the idea a chance. It turns out that the same audio editing software that can create the test signal can do analysis on the levels on playback and give you results in dB and fractions thereof.
I'm also looking at the scripting docs here:
Scripting - Audacity Manual
and I don't see anything that seems useful.
Scripting - Audacity Manual
and I don't see anything that seems useful.
Try spectrum lab.
It would allow you to set up a signal source (or more) on the sound card output, which includes waveform type, level control etc. on the measurement side it will be overkill, but the spectrum analysis display will allow you to monitor the output level.
If you want to get fancy, you could use one channel each of left and right to monitor int input / output transfer function.
The package is freeware, and once you get your head around the configuration of input and output works well.
It would allow you to set up a signal source (or more) on the sound card output, which includes waveform type, level control etc. on the measurement side it will be overkill, but the spectrum analysis display will allow you to monitor the output level.
If you want to get fancy, you could use one channel each of left and right to monitor int input / output transfer function.
The package is freeware, and once you get your head around the configuration of input and output works well.
The relevant tool in Audacity is the Spectral Analayzer.
I have to admit that I have traditionally done this sort of thing using Sound Technology Spec Lab, Audition and Cool Edit Pro which all do this quite well. Sound Technology's Spectrum Lab is the most expensive but IMO also the best:
Spectra Series Signal Analysis & Data Acquisition Software Solutions...
There is another free product called Spectrum Lab that is freeware and oriented towards hams. I really have no experience with it.
Another piece of freeware to look at is VA or Visual Analyzer.
There is a lot of freeware, shareware and commercial product in this area.
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Yes, for System One, I have no personal experience with the Portable One Plus. Are you sure you can't step the generator level as source in a sweep with it's software?
Maybe someone that has one can chime in.
Lukas
Maybe someone that has one can chime in.
Lukas
but maybe I am wrong - hmm - the tech lit says it *will* do amplitude sweeps ...
Advanced Audio - Audio Precision Portable One Plus
so I will take a closer look. Great if it does!
thank you everyone for taking time to try and help
(later) - no, that means sweeps of amplitude vs. frequency. Basically you can sweep any measured parameter -against frequency,not amplitude.
Advanced Audio - Audio Precision Portable One Plus
so I will take a closer look. Great if it does!
thank you everyone for taking time to try and help
(later) - no, that means sweeps of amplitude vs. frequency. Basically you can sweep any measured parameter -against frequency,not amplitude.
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Look at page 4-60 of the owner's manual:
"The starting and ending values for the swept parameter are shown at
the lower center and lower right of the display. They can also be
adjusted by highlighting them and adjusting the AMPLITUDE or
FREQUENCY controls, depending upon whether the swept parameter is amplitude or frequency"
I suggest you sit down and read the manual thoroughly
Lukas
"The starting and ending values for the swept parameter are shown at
the lower center and lower right of the display. They can also be
adjusted by highlighting them and adjusting the AMPLITUDE or
FREQUENCY controls, depending upon whether the swept parameter is amplitude or frequency"
I suggest you sit down and read the manual thoroughly
Lukas
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