Thanks for the feedback! The stuttering is caused by the game's audio mixer. I already rewrote the audio code on top of AHI to solve the uneven framerate, but it's not fit for release yet. The main issue is that the game uses 14 audio channels, and with AHI the more channel you have, the quieter the audio will be:
https://www.lysator.liu.se/(faq)/ahi...te/#faq_volume
With 16 channels reserved the audio output is just way too low. It wasn't a wasted effort though, because other sound libraries will be able plugged into the new audio code with minimal effort.