3d sound problem

hi friends

I use VS 2008 (C#) and managed DirectX, I want to implement 3d sound, I write following code lines:

sounddevice = new DS.Device();
sounddevice.SetCooperativeLevel(this, CooperativeLevel.Normal);

BufferDescription description3D = new BufferDescription();
description3D.ControlEffects = false;
description3D.Control3D = true;


//this lines gives me an error: value does not fall within expected range
explosionsound = new SecondaryBuffer(@"..\..\artwork\fly.wav", description3D, sounddevice);


explosion3D = new Buffer3D(explosionsound);


that does this error mean? how can I solve it? is there any sample?