diff --git a/code/nel/include/nel/sound/driver/buffer.h b/code/nel/include/nel/sound/driver/buffer.h
index 5d488f1c7..27a8d9f00 100644
--- a/code/nel/include/nel/sound/driver/buffer.h
+++ b/code/nel/include/nel/sound/driver/buffer.h
@@ -48,6 +48,8 @@ public:
 		/// Intel/DVI ADPCM format, only available for 1 channel at 16 bits per sample, encoded at 4 bits per sample.
 		/// This is only implemented in the DSound and XAudio2 driver.
 		FormatDviAdpcm = 11, 
+		/// No format set. Used when a TBufferFormat value has not been set to any value yet.
+		FormatNotSet = (~0),
 	};
 	/// The storage mode of this buffer. Also controls the X-RAM extension of OpenAL.
 	enum TStorageMode
diff --git a/code/nel/src/sound/driver/xaudio2/source_xaudio2.cpp b/code/nel/src/sound/driver/xaudio2/source_xaudio2.cpp
index df8101b40..7ee723787 100644
--- a/code/nel/src/sound/driver/xaudio2/source_xaudio2.cpp
+++ b/code/nel/src/sound/driver/xaudio2/source_xaudio2.cpp
@@ -121,8 +121,7 @@ void CSourceXAudio2::commit3DChanges()
 {
 	nlassert(_SourceVoice);
 	
-	// Only mono buffers get 3d sound, multi-channel buffers go directly to the speakers (calculate rolloff too!!).
-	// Todo: stereo buffers calculate distance ?
+	// Only mono buffers get 3d sound, multi-channel buffers go directly to the speakers without any distance rolloff.
 	if (_Channels > 1)
 	{
 		// _SoundDriver->getDSPSettings()->DstChannelCount = 1;
@@ -535,7 +534,7 @@ bool CSourceXAudio2::preparePlay(IBuffer::TBufferFormat bufferFormat, uint8 chan
 		// destroy adpcm utility (if it exists)
 		delete _AdpcmUtility; _AdpcmUtility = NULL;
 		// reset current stuff
-		_Format = (IBuffer::TBufferFormat)~0;
+		_Format = IBuffer::FormatNotSet;
 		_Channels = 0;
 		_BitsPerSample = 0;
 	}