Feature request about sine wave generator

lorrain

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John,
I suggest an improvement on the sine wave generator .
The possibility of adding sinus harmonic distortion is very interesting to see the effect on the THD, THD+N, .. It's a good way to have a better understanding of all this.
Similarly, I suggest the possibility to add low-level pink noise as well (pink random in particular). This also allows to simulate the background noise in equipments and to see the effect on THD, THD+N, …
Thanks
Eric
 

John Mulcahy

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Why pink? You can use the dither setting to add uniform noise, though the maximum level is at the 16th bit.
 

lorrain

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Thank you for your reply.
I tested the dither/16 bits but no big effect on the noise (with my sound cards)
Pink noise (random) gives visual noise in spectrum mode similar to background noise (noise foor) and the interest for me of adding noise concerns the understanding of THD, THD+N, D+N,…
But I don't know if this request is relevant for that.
I am not a specialist in FFT and other mathematical functions, but software like REW makes it possible to understand many things because REW is both pleasant , easy to use , detailed , rigorous and well documented.
I fully understand that my request is perhaps not pertinent and does not fall within the priority of REW.
 

trobbins

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Lorrain, are you aware that REW does already include a sinewave addition of harmonics function ?
 

lorrain

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Trobbins, thank for your comment.
I have seen this feature and played with it to see the effects on the THD...
But, this feature has not been implemented for playing or learning.
I also support jschwender's request to improve this feature of adding harmonics with the aim of "reducing" or "cancelling " the harmonics of sine generators. I tested in the current state and it can be promising after evolution.
My request is more curiosity or learning than a real need. If there is no echo in the community, it's not really a good idea !!
 

trobbins

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lorrain, can I recommend some other posts on other forums that indicate REW's harmonic addition function is quite a fully fledged feature as far as I have been able to confirm:
https://www.diyaudio.com/community/threads/distortion-analysis-a-thought-experiment.341272/page-3 this link relates to my early days of using the feature.
https://www.diyaudio.com/community/threads/using-a-notch-filter-to-assess-soundcard-adc-and-dac-side-harmonic-distortions.381839/#post-6911235 this link relates to my more recent efforts.
 
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