Something is off. The atmos speakers don't have that much going on, nevermind breaking up a decent 6" bookshelf speaker. You sure it's not the amp kicking the bucket when all channels are driven into that particular load? 14' away is a bit much for a 4" woofer, I'd cross that sucker over as high as possible and kick it down a couple db's.... call it good. Have photos of the setup?