Are there any high-flow cats that aren't loud?
 

Some members are telling me that the final and fatal restriction in my exhaust are my OEM cats and that changing to high-flow cats is essential.

However, my Borla exhaust is on the brink of intolerably loud (apparently the sedan version is MUCH louder than the coupe) and drones mercilessly below 2500 rpm. I might be willing to try high-flow cats, but the last thing I want is more noise - especially if it's raspy.

Does increased noise just go with the territory with high-flow cats, or are there some that work without adding to the noise level?