Aftermarket exhaust, no difference in sound?

[SNEAKYRAPTOR]

Thanks for the input guys.
I recall there is a centre box on the exhaust, is this purely for sound-deadening purposes? And the decat pipe is on my to-do list as well, cheers for the tip.
Ruan, the box was originally for a petrol I believe yes, although it makes no odds to the noise whether the box is on or not, I suspect then the issue is further up the pipe, ie middle box and cat.