have the chance of putting a a custom made back box on my sti it's a twin 4.5 inch.Their is no restriction in it ie it's straight through,will it loose all of it's throaty noise and just sound like a tank?I have a 3.5 inch on at the moment and it grunts and snarls really well.I don't know if it has any sort of baffeler in it hope somone can help.

 

Twin 4.5"...?