Re: OPS Inc. R3E2C brake question.
I have one installed on a 20" rifle and I don't find there to be a major increase in noise compared to most other brakes I have used (or still use).
However, you are making an apples/oranges comparison at best if you are asking if the Ops Inc Brake will be louder than any given flash hider (A2 type or otherwise). Flash hiders general aren't "loud" to speak of, but anytime that you purposefully divert gases in an attempt to reduce muzzle climb/recoil like you do with a brake, you increase the noise perceived from the blast ports in the brake (some increase can be noted by the shooter...most often by those around the shooter in the direction the ports on the brake are pointed, usually to the sides or back at a 45deg angle get the blast).
So, if you are asking if the Ops brake will be louder than an A2-type flash hider...Absolutely without a doubt. How much louder, well, perception is 9/10 of reality, so it all depends on how YOU and those around YOU perceive it.