I just acquired a new pair of ATH-CK7's canalphones. Right out of the package I put them in my ears, turned on the iPod/Tomahawk and Bam! Muddy bloated bass and a no extension high end. The highs sounded like the V-Moda Vibes I used to own where I had to boost the treble on my iPod just to make them sound OK. I had read about burn-in using pink noise to bring out the true fidelity of the phones but frankly didn't buy it. I put over fifty hours of music through the Vibes and still couldn't get over the treble veil. Well, I decided to run the CK7's through 20 some hours of pink noise just to see if there was any noticeable difference before I sold them. Well, I'm completely stunned. The highs are now there and the low end has cleaned itself up. I never would have believed it if I didn't try it. I don't know how well this works on other types of headphones, but it sure did wonders for these. Maybe I should have tried this on the Vibes before retuning them?