if you want it to sound like it's throwing power it's going to have to throw power.

a turbo plus good sized exhaust has both a sound deadening effect as well as a sound increasing effect.

:edit:
and because the firing order is 1-2-3-4 and not 1/5-2/6-3/7-4/8 none of the pulses hit each other. that is what gives v6's and v8's their distinctive sound.

the closest you can get to that is having a boxer 4 with unequal length headers.