Avid Pro Tools signal generator and zero-crossings

[Phoenix]

When using the Avid Pro Tools signal generator sound effect to create a sine wave, such as 20 Hz or 100 Hz, why does the resulting waveform not have zero crossings at integer seconds? Or in other words, how precise is the frequency of the PT signal generator?

 

[Venn Diagram]

I do not believe the generator's frequency is synchronized to the grid until you record it and then align it.

 

[Northern Lights]

I conclude that it was just never intended to be precise with the frequency value.

 

[Phoenix]

I do not believe the generator's frequency is synchronized to the grid until you record it and then align it.

You are correct when, for instance, the plugin operates on an auxiliary track and sends to a bus, and you record that bus. I have tested this myself. However, I was only referring to situations where you generate the tone by either rendering it with the AudioSuite version of the plugin or by bouncing the plugin on a track.

 

[Deez Treez]

The PT signal generator only supports integer frequencies. It seems that when the signal generator plugin was developed years ago, the calculations were designed to have limited accuracy. It is possible that rounding errors have occurred over time, which could be the cause of the issue.

 

[NahDontLook]

It is simply an oscillator and not a MIDI instrument.

 

[Phoenix]

It is simply an oscillator and not a MIDI instrument.

If it oscillates 20 times per second, it should return to its starting point after one second.

My point is that 20 Hz doesn't look like 20 Hz to me.