[recursive]

Adding more channels does nothing to the overtone information. From what I can find[1], it seems that the phase of the 25% and 75% waves are such that the two waves are actually inverse of each other. I don't know much about Gameboy hardware though. Do you actually know what the point of this is?

[1]: https://gbdev.gg8.se/wiki/articles/Gameboy_sound_hardware#Sq...

[magicalhippo]

Sure, but having a channel with 25% duty cycle of frequency f and a channel with 75% duty cycle of frequency 3f will lead to a different waveform after mixing compared to 75% at f and 25% at 3f, no?

Depending on how that's processed downstream it could sound very different I imagine.

In crude ASCII art (two inputs mixed to an output):

  ---_________
  
  ---_---_---_
  
  
  ¨¨¨_---_---_

vs

  --------____
  
  -___-___-___
  
  
  ¨---¨----___

[recursive]

I saw a video a few years that provided pretty convincing experimental evidence that's not actually the case.

https://www.youtube.com/watch?v=Ffka-hPzug0

[magicalhippo]

Very interesting, though any non-linear effects would definitely get affected.

Not sure how much that comes into play on the Gameboy though.

[charcircuit]

If you play 2 inverse waves it will sound different than 2 of the same wave.