5zigen fireball VS. n-1 Dual

ok i've narrowed it down to those two. fireball has 2.5" pipe so it better for my car, it probably sounds really nice  and deep, b/c of more restiction. but the dual looks a #### of  alot nice, and i plan an engine swap soon where bigger piping will be better so the piping doens't matter, as long as i don't get a lot of backfiring. so if i get the dual, when i accelerate, will i have to floor it to get the nice deep sound.. or does it keep its sound nice and deep constantly, and change as i accelerate. does anyone possibly have sound clips.. i heard that someone had them form a month or two back on the boards. thanx a lot
-dave