A few yrs ago I had an T-Bird SC-car was all stock, came w/a resonator and 2 muffler setup(or 1 muffler and 2 resonators-however way you want to look at it!).
There was 1 in the middle of the exhaust(2 in and 2 out)that went into a resonator(muffler)to each side. Sounded really tinny and wimpy! All I did was cut out each resonator and replace w/a piece of straight pipe w/a chrome extension and it sounded mean!! nice rumble at idle and wot!!
At 1st I tried to replace them w/2 dynomax mufflers and it sounded worse then stock! just my personal expierance. Much better w/just straight pipe.