Update (9/17/2013) Graph says it all _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ So far my collection of headphones has only been the Koss KSC75, DT990-600's, Grado 60i's and Sony V6's. My experiences so far? The KSC75 and DT990 are nearly identical, despite the $300 Difference. The DT990's just have a larger soundstage, bit less distortion, and more exaggerated highs. In all honestly, i prefer my 75's. Why? They're more comfortable. They Sit on my ears and do not apply any clamp pressure nor weigh the top of my head down, and the lessened highs of the 75's are less fatiguing. Look how similar the curves are to the DT990's. Despite the curve, i can't tell a difference in the bass response. This is possibly due to my source's 10-ohm output impedance. And the M50's, despite a $100 Difference. Odd similarity to Equal Loudness Curve. Checkout the boosted bass, 2k Hz peak, and 10k Hz Spike. Shockingly close to that magical goal. So head-fi, i beg you, don't forget the Koss ksc75's in all the "hidden gem" hype threads.