Hello all. I'm curious about this and hope someone can explain to me why it works this way. This is a comparison of the frequency spectograms of Kirby Air Ride's menu music. The top is the original HPS format file from the game, which is at a 32 kHz sampling rate (I've upsampled it with SoX to 48 kHz for a comparison of the same scale), and the bottom is a recording of the same from Dolphin 4.0-330 (but this goes back to at least 3.5) using DSP LLE and XAudio2 that's been boosted by 2.04 dB to match the original's volume. As developers surely know, a 32 kHz file can't contain sounds greater than 16 KHz in frequency, but Dolphin outputs up to 24 kHz.
It appears to be generating a mirror image of the lower frequencies starting at 16 KHz. Dolphin does the same with Wii games too, but I know a real Wii doesn't do this. In fact, a real Wii appears to output at 32 kHz even when the source files on the disc are 48 kHz (tested with Shiren the Wanderer). I don't know how or why this can even happen. Can anyone please explain it to me?
It appears to be generating a mirror image of the lower frequencies starting at 16 KHz. Dolphin does the same with Wii games too, but I know a real Wii doesn't do this. In fact, a real Wii appears to output at 32 kHz even when the source files on the disc are 48 kHz (tested with Shiren the Wanderer). I don't know how or why this can even happen. Can anyone please explain it to me?