diff --git a/src/mame/audio/seibu.c b/src/mame/audio/seibu.c
index 5de168e145b..70828efa8e1 100644
--- a/src/mame/audio/seibu.c
+++ b/src/mame/audio/seibu.c
@@ -159,7 +159,7 @@ static STREAM_UPDATE( seibu_adpcm_callback )
 				state->playing = 0;
 		}
 
-		*dest++ = clock_adpcm(&state->adpcm, val);
+		*dest++ = clock_adpcm(&state->adpcm, val) << 4;
 		samples--;
 	}
 	while (samples > 0)
diff --git a/src/mame/drivers/mjkjidai.c b/src/mame/drivers/mjkjidai.c
index c189fdde897..b9cd86dc300 100644
--- a/src/mame/drivers/mjkjidai.c
+++ b/src/mame/drivers/mjkjidai.c
@@ -63,7 +63,7 @@ static STREAM_UPDATE( mjkjidai_adpcm_callback )
 				state->playing = 0;
 		}
 
-		*dest++ = clock_adpcm(&state->adpcm, val);
+		*dest++ = clock_adpcm(&state->adpcm, val) << 4;
 		samples--;
 	}
 	while (samples > 0)
diff --git a/src/mame/drivers/renegade.c b/src/mame/drivers/renegade.c
index f01a3f82d17..3d2572e2b03 100644
--- a/src/mame/drivers/renegade.c
+++ b/src/mame/drivers/renegade.c
@@ -154,7 +154,7 @@ static STREAM_UPDATE( renegade_adpcm_callback )
 				state->playing = 0;
 		}
 
-		*dest++ = clock_adpcm(&state->adpcm, val);
+		*dest++ = clock_adpcm(&state->adpcm, val) << 4;
 		samples--;
 	}
 	while (samples > 0)