I'm supprised Snoopy didn't catch this one yet!
Anyway... take it easy on the noob.
When talking about headers... we here on HAN think you're talking about a V8 or something which has 2 headers. All honda 4 cylinder engines only have 1 header. (singular)
About your question... if you still have the original cat, resonator and muffler... the addition of a header will not make your car that much louder. But if you decide to add a high flow cat and a straight through performance muffler then you may find it becomes very loud. In general... if you really want something that will perform and still be relatively quiet... be prepared to pay up!