Does resampling degrade the sample?

Elektron Gear Digitakt
#22

Nice measurements! I too like to measure things.

10x seems to be enough to at least see a difference (-10dB?).

The test was done in a new Project without any parameter changes. The EQ was set to infinite hold.

#1: I uploaded a sine sweep (20Hz-20kHz@ -3dB).

-3 Sweep
-3 Sweep1560×670 67.9 KB

#2: Uploaded into the Digitakt it seems to clip a bit. Kind of disappointing. Maybe due to the bit rate change from 48 to 16 though - wouldn’t read too much into it.

Sweep 1x
Sweep 1x1554×673 71.9 KB

#3: After resampling the sample 10 times, a pretty specific EQ curve emerges.

Sweep 10x
Sweep 10x1561×673 63.3 KB

Note:
I could have done more with a spectral graph, but I just wanted to share this. If you want more, let me know.

Maybe somebody could do a noise test, but the same EQ curve would probably be found.

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#23

Hey that looks pretty interesting! Very much in line of what @robbret found out.

I’m not really familiar with that monitoring tool (?), what are the blue bars and what are the yellow/red lines? I mean I get the gist of it – there’s a treble boost – but would be nice to be able to read the rest of these images.

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#24

I used the Test Oscillator in Logic to create the sine sweep sample. I then monitored it with the Multimeter Analyzer.

You can ignore the blue bars. They represent the position of the sine wave sweep when I took my screen capture. The yellow lines are on infinite hold, so they are fully representative of the frequency response.

The yellow lines represent peaks. You can see #1 and #2 are relatively flat, but #3 shows a clear EQ curve as a result of the sampling.

The red lines represent clipping, but I wouldn’t read into it. It’s probably just from bit rate conversion in Logic which wouldn’t drastically change the frequency response.

I felt @robbret showed the time domain changes well, but I thought the frequency domain could be shown more clearly with a more stable measurement. I was also just curious what it would look like.

In a way (maybe more cutting than boosting). I tried to match this EQ curve. It looks like a 1.20Q @ 4kHz HPF. This curve would extend to just to around 8kHz like in the #3 example. However, there’s also a bit of high roll off and even more low roll off, so it’s definitely not just a simple HPF.

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