well it depends also with the rest of your exhaust. like if u have the apexi n1 or something along with the testpipe, geez, its going to be loud.

if u dont want it be soo loud i would keep your bpipe of your exhaust and switch mufflers. like a mugen twinloop or itr axleback.

im running header with a 2.5 collector with gutted cat and stock itr bpipe and axleback and it sounds stock.

ill be running a different header, testpipe, different bpipe and stock itr axleback pretty soon, i was told it should be pretty quiet.