Extreme pure sine (0.0007% THD+N) with level of 775 mVrms
15 Hz - 400 Hz - 1000 Hz - 3000 Hz - 6000 Hz - 12000 Hz - 18000 Hz
Sine Ultrapure
15 Hz - 400 Hz - 1000 Hz - 3000 Hz - 6000 Hz - 12000 Hz - 18000 Hz
Sine Ultrapure
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I use it to see how much noise is added to the bottom from the D.U.T. and
many of the generator tools do not have a 'like' low reference noise level.
Your generator have this very low low low noise signal ?
Obviously the gain of the player must be put at the highest level ie 0 dbfs.
We do not care the volume but the bottom noise 🙂
many of the generator tools do not have a 'like' low reference noise level.
Your generator have this very low low low noise signal ?
Obviously the gain of the player must be put at the highest level ie 0 dbfs.
We do not care the volume but the bottom noise 🙂
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It does exist in the virtual space. As soon as it becomes materialized, it won't be ultra pure any more.
Yes it is a good starting point. Is it dithered? Can you recommend same in 16-bit 44.1 kHz format that I can write on CD, to be able to do tests on a CD player?
Double negatives don't mean what you think they mean 😉
Why wouldn't someone just generate their own tones using Audacity? Not that tones are terribly useful in themselves....
these are all generated with calibrated and certified equipment, we are not think to the tones, but focalizes the point to the noise and a bit of impedance in the various frequencies.
this is no dithered (pure)
to test the noise floor of a cd player I had not thought of but you can try to see what comes out...
Audacity is not very suitable to see these things.
One of the waveform file displayed with a suitable program to do these things, it is Wavosaur, you can see well the very low noise floor...
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I have analog sources 20 dB better than that. Most digital generators digital files are good for 200 dB.
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The files that would be useful are sines at levels 1 dB steps to -20 and 10 dB steps to -150. Also IM files and Jtest jitter files. Also at different sample rates. I have various ways to generate these but Im always checking them for accuracy.
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Please, talking about analog sources or digital source ?
analog like this ?
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Regards my original sine source this is the 1000 Hz in ARTA with 'spectral density' active.
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Added wav file with a kind of frequency response made with a 20 tones and almost 4 dbu to the origin output.
Sine Ultrapure
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Sine Ultrapure
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I agree, but honestly I have not found another more appropriate term to describe such a low level of distortion in a few lines 🙂 (see web page limit)
QUASI-PURE is more certainly correct.
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You seem to be saying that a wav recording of a generated sine wave, when played back on a separate system, somehow is purer?
Since there is obviously some sort of language barrier here, I am probably wasting my time. I am saying you can generate a pure tone wav file using audacity. Distortion and noise will be limited only by the player and the technical limits of the format bit depth and sample rate. Best performance when analysing will be when the frequency is an integer divisor of the sample rate - e.g. for 44100 you would use 44100/44=1002.2... instead of 1000Hz, etc.
Audacity as a spectrum analyzer is limited, but that is not what I was suggesting it be used for..
You not wasting your time. 🙂
In fact, just to save time I have created these files,
certain that can be generated each time and with any good software.
My method works with any good software player (or any device/application that support wav format) and over the speed of use
I also created a good 'reference' to work with the overlay.
So I can see 'how much' noise was added by DUT under test.
I hope of having explained a little better the mechanism.
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Analog sources with distortion products at -150 dB. Check the low distortion oscillator thread on the subject.
FFT's can have various artifacts that are not in the actual data. Its in the windowing and number of samples processed. It gets involved to get good data. Ill look at one of your files when Im next in front of my pc.
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