Hi Racerboy,
some days ago I posted a link in 'Dual exhaust for subs' thread where you can download blue tracings for several german sub types [e.g. IXD2], maybe you missed that.
http://www.subsim.com/radioroom/show...2&postcount=40
Look for 'Auspuff' [muffler].
Greeting,
SquareSteelBar