Just for fun, here's my setup process. Starting with a freshly installed GOG copy.

Grab the latest DOSBOX Staging: https://dosbox-staging.github.io/downloads/windows/

In the "Realms of the Haunting" folder rename DOSBOX to something like DOSBOX_OLD

Create a new DOSBOX folder and copy the extracted files from the DOSBOX Staging .zip into it

Run Realms of the Haunting\DOSBOX\Dosbox.exe. Two Windows will open up. In the "DOSBox Status Window" look for a line that says "CONFIG: Wrote new primary conf file" (it was about 10 lines down in my case) copy the location specified and go to it in a new folder window. (For me: C:\Users\Crim\AppData\Local\DOSBox)

Copy the newly created "dosbox-staging.conf" into your "Realms of the Haunting" folder.
Now in the same "Realms of the Haunting" folder rename "dosboxROTH.conf" to something like dosboxROTH_old.conf and then rename "dosbox-staging.conf" to "dosboxROTH.conf"

At this point from the "Realms of the Haunting" folder run:" Launch Realms of the Haunting". You should see the DOSBox Staging logo followed by the game starting up and playing.

Now if using the US transformation patch (https://community.pcgamingwiki.com/files/file/746-realms-of-the-haunting-uk-to-us-patch), open the .7z and copy all the files TWICE. Into both "Realms of the Haunting\DATA" and "Realms of the Haunting\ROTH" Make sure to Replace the files when asked.

So not sure which MIDI option you're going with. I like to use Sound Canvas VA myself. But I'll quickly go over setting up a soundfont internally with DOSBox Staging just in case.
First, download a soundfont. I'll use Fatboy for this example: https://web.archive.org/web/20220124174052/https://fatboy.site/
Extract "FatBoy-v0.790.sf2" to the "Realms of the Haunting\DOSBOX" folder

Now edit "dosboxROTH.conf" and change the following options:
Under [midi] and under [fluidsynth] Save and quit

Now copy "Realms of the Haunting\DATA\Readme.txt" to the "Realms of the Haunting\ROTH" folder. This is necessary to get the install program to run.

Edit "Realms of the Haunting\dosboxROTH_single.conf" with notepad or something similar. to Again, from the "Realms of the Haunting" folder run:" Launch Realms of the Haunting". It should now run the install program (If it doesn't your likely missing the readme.txt from the earlier step).

'Select Sound Device" and allow it auto detect. Do NOT use this device for music, instead select "General MIDI" and "330 Default". Both sound tests should showcase sound/music. Make sure to exit and allow it to save the configuration.

Again, edit "Realms of the Haunting\dosboxROTH_single.conf" and change the following: Almost done. Again, from the "Realms of the Haunting" folder run:" Launch Realms of the Haunting" Under the settings, change the gamma to the lowest possible setting for the lowest amount of purple tint.

If you want to play around with DOSBox Stagings resolution and video renderer for this game you can do so by editing "dosboxROTH.conf".


Note: The first interplay logo video will likely be messed up, however that was the only one on my playthrough.
Have Fun!