exhaust 2pg replace

[oldschool21]

removed my exhaust system the muffler hade a rattle so i cut it open with a chop saw found out the center part the baffler had rusted out and fell to the bottom of the muffler body took the main pipe to a muffler shop the smallest pipe they had was 1.75 they bent 2 45 degree angles to make a new s bend now have a new main pipe ran the pipe out the back went by lawn mower place got a new muffler for a 16 hp when i started it up it has same power and noise level was wanting it to be quieter so back to the drawing board on muffler needs to be round no bigger than 3.5 round any ideas the new muffler is under the cart in the back has tail pipe its nice not smelling the exhaust just want it quiet i drive my kids to the bus stop every morning at 730 dont want my neighbors to start taking pop shots at me in the am any ideas would be helpful thanks