I have a small crack In my downpipe don't joe how that happened. Anyways I have a cobb catback if I go catless will that be significantly louder?
I have a 3in catless exhaust system with a glasspack. I love the sound. Is it loud? Sure some may say its loud. Does it set off car alarms? In the ocasional parking garage, yes. On the highway just turn up the sound system! Never had any problems or tickets with it.
Catless/high flow cats on a wrx+ a tune is pretty much a necessity for all WRX owners. Just go catless and get a tune, you will be much happier. To answer your question, yes it will be marginally louder but the cobb catback to my understanding is pretty quiet. http://www.turbomagazine.com/tech/0212tur_subaru_wrx_exhaust_dyno_results/viewall.html thats a pretty good website to compare the different exhausts.
sorry to hijack - I just read the title of the thread as "Downed Crackpipe" Also, the turbo baffles the exhaust sound. SRT4's don't have a muffler.