Muffler-can keep kinda quiet sounds off at rpm

I went from a 2" full system with cheap muffler shop turbo mufflers to a full 3" system with Dynomax super turbo mufflers. Difference was night and day, both in noise reduction and low end grunt. The small system droned horribly, and the 3 inch was far quieter in the car, but had a good bark under WOT. Car was a 70 Dart, mild 360 auto, tti headers.