diff --git a/src/arch/Sound/DSoundHelpers.cpp b/src/arch/Sound/DSoundHelpers.cpp
index 1474ea6c89..27cd5e6a5b 100644
--- a/src/arch/Sound/DSoundHelpers.cpp
+++ b/src/arch/Sound/DSoundHelpers.cpp
@@ -70,7 +70,7 @@ void DSound::SetPrimaryBufferMode()
 		preferredSampleRate = kFallbackSampleRate;
 	}
 	waveformat.nSamplesPerSec = preferredSampleRate;
-	waveformat.nBlockAlign = 4;
+	waveformat.nBlockAlign = (waveformat.nChannels * waveformat.wBitsPerSample) / 8;
 	waveformat.nAvgBytesPerSec = waveformat.nSamplesPerSec * waveformat.nBlockAlign;
 
 	// Set the primary buffer's format