I don't have the GOG version as of yet so I'm basing this off how I got my retail version working using dosbox. I'm kind of assuming they used the dosbox version. You should see a dosbox splash screen if it uses it. Or you can check in the game's install folder and see if you see a folder called "dosbox" in there.
Before you do this make sure you have "hide extensions for known file types" deselected in the "folder options" under the "view tab" so windows can display the file extension. (see attached pic)
Their naming convention for the dosbox configs is usually dosbox<game name> (without the carrots) with a .conf file extension. Once you find this you can just right click on it to copy it and back it up somewhere. Next you just open it in a text editor like notepad and scroll to the main sections listed (sdl, dosbox, renderer, and cpu) and make the following changes. If it's difficult to find those main sections use the search feature in the text editor (notepad.exe).
Out of curiosity, what is the "date modified" time stamp on the file named "DACBLAST.DRV" in the main game folder?
You can right click on it and select properties on it to find out. The reason I ask is that file is a soundblaster driver used with sound. There were some patched versions of that driver floating around that made the sound work better.