I too have an E17 and E9 and I found some similar observations: However, to my ears, the gain switch on low is better, but leaving LO Bypass off does provide an overall more neutral experience. The E17 with bypass off and with no EQ sounds thinner than E9, (a tiny bit weaker in bass, a little...

So I've scoured through all the forum posts possible for mods on my ATH M50, and looked at/considered all the options for mods.  I removed the damping material behind the driver first, and decided that I liked that change, so I looked for further improvements.  I ordered the DT250 pads, and...