diff --git a/source/audiolib/src/driver_adlib.cpp b/source/audiolib/src/driver_adlib.cpp
index 5cb4b7c71..57b83b933 100644
--- a/source/audiolib/src/driver_adlib.cpp
+++ b/source/audiolib/src/driver_adlib.cpp
@@ -200,6 +200,7 @@ static int AL_LeftPort  = ADLIB_PORT;
 static int AL_RightPort = ADLIB_PORT;
 int        AL_Stereo    = TRUE;
 static int AL_MaxMidiChannel = 16;
+int        AL_AdditiveMode;
 
 // TODO: clean up this shit...
 #define OFFSET(structure, offset) (*((char **)&(structure)[offset]))
@@ -331,9 +332,13 @@ static void AL_SetVoiceVolume(int const voice)
     if (timbre->Feedback & 0x01)
     {
         int const slot = slotVoice[voc][0];
+        uint32_t t2;
 
         // amplitude
-        auto t2 = (Channel[channel].Volume * t1) >> 15;
+        if (AL_AdditiveMode)
+            t1 = (uint32_t)VoiceLevel[slot][port] * (velocity + 0x80);
+
+        t2 = (Channel[channel].Volume * t1) >> 15;
 
         volume = t2 ^ 63;
         volume |= (uint32_t)VoiceKsl[slot][port];
diff --git a/source/audiolib/src/driver_adlib.h b/source/audiolib/src/driver_adlib.h
index 1ddd90544..5b2e8d036 100644
--- a/source/audiolib/src/driver_adlib.h
+++ b/source/audiolib/src/driver_adlib.h
@@ -23,6 +23,7 @@
 #include "opl3.h"
 
 extern int AL_Stereo;
+extern int AL_AdditiveMode;
 
 int         AdLibDrv_GetError(void);
 const char *AdLibDrv_ErrorString(int ErrorNumber);
diff --git a/source/audiolib/src/fx_man.cpp b/source/audiolib/src/fx_man.cpp
index c58bea115..292fe8b69 100644
--- a/source/audiolib/src/fx_man.cpp
+++ b/source/audiolib/src/fx_man.cpp
@@ -56,7 +56,7 @@ static int osdcmd_cvar_set_audiolib(osdcmdptr_t parm)
 
     if (!Bstrcasecmp(parm->name, "mus_emidicard"))
         MIDI_Restart();
-    else if (!Bstrcasecmp(parm->name, "mus_adlibstereo"))
+    else if (!Bstrcasecmp(parm->name, "mus_al_stereo"))
         AL_SetStereo(AL_Stereo);
 
     return r;
@@ -72,7 +72,8 @@ int FX_Init(int numvoices, int numchannels, int mixrate, void *initdata)
 
         static osdcvardata_t cvars_audiolib[] = {
             { "mus_emidicard", "force a specific EMIDI instrument set", (void *)&ASS_EMIDICard, CVAR_INT | CVAR_FUNCPTR, -1, 10 },
-            { "mus_adlibstereo", "enable/disable OPL3 stereo mode", (void *)&AL_Stereo, CVAR_BOOL | CVAR_FUNCPTR, 0, 1 },
+            { "mus_al_stereo", "enable/disable OPL3 stereo mode", (void *)&AL_Stereo, CVAR_BOOL | CVAR_FUNCPTR, 0, 1 },
+            { "mus_al_additivemode", "enable/disable alternate additive AdLib timbre mode", (void *)&AL_AdditiveMode, CVAR_BOOL, 0, 1 },
         };
 
         if (!init++)