I've learned to listen deeper, but can't really decipher differences in IC's or speaker cable. I did notice a substantial difference in a dedicated circuit and Portport. I can also tell blindly if my speaker grills are on or off. No matter how hard I try and burn a good cd for the car, it can't get past a test on the main system it sounds so bad. Headphones are a different story. I had Blue Jeans make me a 15' cord for my AKG702's and it sounds better than the stock without question.