DirectSound3D - Muting the sound at max distance

Hi. This ones for the sound guys. I am using DSBCAPS_MUTE3DATMAXDISTANCE to mute the sound (save processing power) when the sound goes beyond the max distance from the listener. However, attenuation stops at max distance but the sound does not mute. Any ideas please. I have included the relevant code (I think this is all u need). Cheers.

------ CODE START ----------------------------

Private Sub cmdInit_Click()

On Error GoTo ErrHandler

If cmdInit.Caption = "INITIALISE" Then

cmdInit.Caption = "REINITIALISE"
sbAngle.Enabled = True
sbDistance.Enabled = True
sbVolume.Enabled = True
sbVelX.Enabled = True
sbVelY.Enabled = True
sbVelZ.Enabled = True
sbDoppler.Enabled = True
sbRollOff.Enabled = True

End If

cmdPlay.Enabled = True
cmdStop.Enabled = False

If ObjPtr(DSListen) Then Set DSListen = Nothing

If ObjPtr(DSPrimBuffer) Then Set DSPrimBuffer = Nothing

If ObjPtr(DSBuffer3D) Then Set DSBuffer3D = Nothing

If ObjPtr(DSBuffer) Then

DSBuffer.Stop

Set DSBuffer = Nothing

End If

BufferDesc.lFlags = DSBCAPS_CTRL3D Or DSBCAPS_CTRLVOLUME Or DSBCAPS_GETCURRENTPOSITION2 Or DSBCAPS_MUTE3DATMAXDISTANCE

Set DSBuffer = DS.CreateSoundBufferFromFile(App.Path & "\blip.wav", BufferDesc)

If Option1.Value Then BufferDesc.guid3DAlgorithm = GUID_DS3DALG_NO_VIRTUALIZATION

If Option2.Value Then BufferDesc.guid3DAlgorithm = GUID_DS3DALG_HRTF_LIGHT

If Option3.Value Then BufferDesc.guid3DAlgorithm = GUID_DS3DALG_HRTF_FULL

Set DSBuffer = DS.CreateSoundBufferFromFile(App.Path & "\blip.wav", BufferDesc)

Set DSBuffer3D = DSBuffer.GetDirectSound3DBuffer

' Setup DSBuffer

DSBuffer.SetVolume sbVolume.Value

' End setup

' Setup DSBuffer3D

DSBuffer3D.SetPosition Sin(sbAngle.Value * RAD) * sbDistance.Value, 0, Cos(sbAngle.Value * RAD) * sbDistance.Value, DS3D_DEFERRED

DSBuffer3D.SetMinDistance 10, DS3D_DEFERRED

DSBuffer3D.SetMaxDistance 90, DS3D_DEFERRED

DSBuffer3D.SetVelocity sbVelX.Value, sbVelY.Value, sbVelZ.Value, DS3D_DEFERRED

DSBuffer3D.SetConeAngles 90, 180, DS3D_DEFERRED

DSBuffer3D.SetConeOrientation 0, 0, -1, DS3D_DEFERRED

DSBuffer3D.SetConeOutsideVolume -2500, DS3D_DEFERRED

' End setup

PrimBufferDesc.lFlags = DSBCAPS_CTRL3D Or DSBCAPS_PRIMARYBUFFER Or DSBCAPS_MUTE3DATMAXDISTANCE

Set DSPrimBuffer = DS.CreatePrimarySoundBuffer(PrimBufferDesc)

Set DSListen = DSPrimBuffer.GetDirectSound3DListener

Set DSPrimBuffer = Nothing

' Setup DSListen

DSListen.SetPosition 0, 0, 0, DS3D_DEFERRED

DSListen.SetOrientation 0, 0, 1, 0, 1, 0, DS3D_DEFERRED

DSListen.SetDopplerFactor sbDoppler.Value / 10, DS3D_DEFERRED

DSListen.SetRolloffFactor sbRollOff.Value / 10, DS3D_DEFERRED

' End setup

DSListen.CommitDeferredSettings

Exit Sub

ErrHandler:

cmdExit_Click

Debug.Print "cmdInit_Click" & " - Error : " & Err.Description

End Sub

Private Sub cmdPlay_Click()

DSBuffer.Play DSBPLAY_LOOPING

cmdPlay.Enabled = False
cmdStop.Enabled = True

End Sub

------------------ END CODE ----------------