Mild Exhaust+Stock Xpipe = Some Sound Increase, but no Power increase
Mild Exhaust+Test pipes (Or primary delete Xpipe) = Some sound Increase, Some Power Increase
Mild Exhaust+Sport Xpipe(HFC) = A Tad more Sound Increase, Some Power Increase
Mild Exhaust+Catless Xpipe = Most Sound increase for that Exhaust, Most Power Increase
Replace Mild exhaust with the Axle back of your choosing to get desired sound level.