I had a similar noise with my SRAM Rival crankset, and I took every measure in the book to try and get rid of it.

And you know what the problem was? A loose cassette (i.e. not the crank or BB)! The lockring on the cassette had loosened slightly, allowing a wee bit of play, and the sound was amplified through the bottom bracket area. Once the lockring was tightenened, the whole thing was silenced and all is well.

So get creative and look everywhere in the drivetrain setup - you never know what the real culprit might be.