its not really mono but I guess you could use mixerset to mute one of the channels.
Question is why?! not much is in stereo?

Simply select Sound Blaster or Sound Blaster 2.0 in games instead of SB Pro/SB16. You can also change the BLASTER variable accordingly.

ps: you can actually select SB Pro in games as well, which is mono on all SB16 cards, too. Or in other words: You only ever get stereo sound if the software supports SB16 and you choose exactly that.

My PM7300 has only one mono-speaker. My PC-Card has a Vibra16 Soundblaster stereo.
Sometimes Music or SFX does not sound right because of the mono-speaker.

dr.zeissler wrote:

My PM7300 has only one mono-speaker. My PC-Card has a Vibra16 Soundblaster stereo.
Sometimes Music or SFX does not sound right because of the mono-speaker.

You can also use a simple Y-cable for that purpose.
The commercially available types do produce shorts, though.
While they do work with most audio hardware, some harware can break if they do contain no caps or resistors on the ouputs.
Personally, I would make a simple adapter cable myself for that purpose.
Either with resistors, caps or little audio transformers (AF transformer, NF-Trafo; 1:10). An optocouplerwould be best, but requires power.
Here's an idea of mine (quick&dirty schematic), which I used for my Commodore 1702 monitor once (mono speaker).
In terms of caps, I'd use 10 µF caps each. Depending on the audio range you like to hear, you can use other values as well.

Thx, there was a special cable-set for wiring the pc-card-sound-out to the feature-connectors on the board.
Because I do nat want to change the wiring I am searching for a software solution.

Ah, I see. I mistakenly assumed the PM was a monitor (like a Sony PVM), not a Mac.
Well, I'm sorry then, I can't help with a software solution. Choosing SB2/OPL2 in-game is the best I can think of, as well.
The last Idea I've got is to do a tiny hardware mod. Solder a 100 nF cap (bipolar) across the L and R output on the Vibra PCB. It will make the signal mono, too.
But be warned, that's not very elegant. It works and is harmless to the hardware, but not very elegant from an audio technican's point of view. 😀

Edit: Please check the Vibra's mixer utility for balance sliders.
Moving them hard left/hard right might solve your problem.