it sounds close to a g35 or 350z but louder. i did have a resonance issue but fix it by removing the interior panels in the hatch and then dyno matting everything and also putting polyester packing tightly into any and every cavity i could find. as i replaced the panels i packed more in. that cut alot of the noise out. now it is a tad bit louder than thy stock system was. stopped a lot of road noise also, and helped the bass my subwoofers put out to sound clearer.