Hi,
I always blamed the sound card and/or headphones, as I have only done this test on a laptop with a shitty integrated soundcard (and I usually don't work with synthesis, nor with such refined processing to require to care too much about subtleties)... but now I doubt.
The attached patch is simply an osc *~ed by a number and connected to the dac i.e.:
[osc~ 500]
|
[*~ 0.05]
|
[dac~]
with a slider ranging from 0 to 0.1 connected to the right inlet of the *~.
Now, to my ear the sinusoid sounds ridiculously distorted, with really very very audible harmonics. Especially if I lower the amplitude to a value below 0.03, which is still enough "loud" to be heared clearly. As I move the slider up and down I can distinctly hear how the harmonic spectrum changes (apart from the obvious clicks in the moment you move the slider).
As I mentioned, I always thought it was the hardware, since I can't believe such an enormous distortion is the normal expected one due to 32 bit float precision...
Or is this the result of the issues that have been mentioned in this thread (table size, linear interpolation)???
On Mon, 2008-03-10 at 11:38 +0100, matteo sisti sette wrote:
Hi,
I always blamed the sound card and/or headphones, as I have only done this test on a laptop with a shitty integrated soundcard (and I usually don't work with synthesis, nor with such refined processing to require to care too much about subtleties)... but now I doubt.
The attached patch is simply an osc *~ed by a number and connected to the dac i.e.:
[osc~ 500] | [*~ 0.05] |
[dac~]with a slider ranging from 0 to 0.1 connected to the right inlet of the *~.
Now, to my ear the sinusoid sounds ridiculously distorted, with really very very audible harmonics. Especially if I lower the amplitude to a value below 0.03, which is still enough "loud" to be heared clearly. As I move the slider up and down I can distinctly hear how the harmonic spectrum changes (apart from the obvious clicks in the moment you move the slider).
As I mentioned, I always thought it was the hardware, since I can't believe such an enormous distortion is the normal expected one due to 32 bit float precision...
Or is this the result of the issues that have been mentioned in this thread (table size, linear interpolation)???
i would assume, that you _are_ triggering a hardware issue. your description sounds like your hardware is running with 16 bit depth. at some point 32float values are converted to the resolution of the hardware. in case your hardware really is running only 16bit, then it is very likely that you hear some artefacts on those very low levels. what you hear then is the quantization error, which is quite perceivable at 16bit, not so much anymore with 24bit.
unless you hardware is running at 24bit (or higher, if that exists), it is not pd's fault.
roman
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i would assume, that you _are_ triggering a hardware issue. your description sounds like your hardware is running with 16 bit depth. at some point 32float values are converted to the resolution of the hardware. in case your hardware really is running only 16bit, then it is very likely that you hear some artefacts on those very low levels. what you hear then is the quantization error, which is quite perceivable at 16bit,
Oh yes of course!!!!! :$:$ You're definitely right.
With so much talk about float precision in the cpu and interpolation and stuff, I forgot about the final quantization of the soundcard :$:$
I didn't know it was _that_ audible at 16 bit however.
-
matteo sisti sette -
Roman Haefeli