i am currently implementing the bandwidth enhanced sinusoidal model for an additive synthesizer, this model allow to accurately produce noisy sounds by adding a noise component to each sinusoids.

But i have some troubles understanding the technical side of that model, to me, it seem that a small amount of filtered white noise is added to each partials so that each bands are widened.

So, in my implementation, white noise samples ([-1, 1] random values, gaussian distribution) is taken from a white noise wavetable, a low-pass filter (Chebychev order 3, cutoff 500, ripple -1., i also tried a simple moving average filter) is then applied on the resulting noise samples, the filtered noise value is then used as a phase step multiplier for the sine oscillators, this actually spread the frequency of the oscillator around as pictured below.

However, the audio result is a kind of background noise and does not enhance the noise part of the sound at all, even with an envelope applied to the noise multiplier.

What is wrong/different with this implementation compared to the model in the article linked above ?

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  • $\begingroup$ Welcome! I'm sorry, I don't understand your first paragraph. It's a four line sentence that just runs on and doesn't make sense. Can you maybe split it into multiple sentences, explain in detail how the "stock" algorithm differs from your algorithm, and what you've done to ensure that the result is comparable, and add more structure in general? You seriously have no full periods in your question, and it's really hard to understand human speech when it's not structured into sentences. $\endgroup$ – Marcus Müller Aug 27 '17 at 18:04
  • $\begingroup$ Sorry! I tried to make it clearer by splitting it in multiple sentences and give more details. $\endgroup$ – Onirom Aug 28 '17 at 15:11
  • $\begingroup$ Nice edit! Much clearer now. But: we'll need to know more about your noise (mainly: distribution shape, variance in relation to the sinusoid amplitudes) and your filters. Maybe actual audio recordings with, and without your enhancement would help! $\endgroup$ – Marcus Müller Aug 29 '17 at 7:46
  • $\begingroup$ I added more details on the filters and distribution shape of the noise. As for the variance, i will see later at home along with audio recordings. $\endgroup$ – Onirom Aug 29 '17 at 11:52

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