From the very first post:
There is a barricade in the highs that although they are nice, they have an invisible plateau that to people with many headphones can tell is there. Some parts just go up and oh so barely get there. So close but there is a barrier for "super highs".
The treble on HD215 over certain frequency need boost, and same applies to bass below certain point. Many amp have loudness button, and many people listen to the music with this button depressed. I'd say Senn designed HD215 to play well in such scenario.
With the price range where HD215 sits I wouldn't really go the route of discussing whether EQ would change SQ. All headphones you mentioned sit around or below $100 price, and you can pay few bucks more to just get M50 (see also other proposed headphones on 'M50 no longer king" thread). There is a Senn for similar money and it's HD449. It does sound pretty well, but you can have ATH-TAD400 for HD215 money, and you get more detailed, more neutral sound. The ATH-TAD400 looks open, but I don't remember it leaking that much. Bottom line, what I'm saying is that for HD215 money you can do much better as long as you are not buying Senn, and then for HD449 money same story. Generally it sounds like Senn is always more expensive than others if you try to compare two headphones proposing similar SQ. For example if you take HD600 and RH-A30, the price difference is three times, and SQ might be just slightly better on HD600. For that money you can get Alpha Dog, HE-400 etc. I always was a big fan of Senn, but now when I discovered that I can have much better headphones from other makers, I am quite disappointed. My last buy was Sony XBA-C10 and they replaced my Senn CX300II. I paid similar money for both, but Senn is boomy, and mids are veiled. While mids on XBA-C10 are simply amazing, and bass has great texture (almost as good as I get on Alpha Dogs!). The XBA-C10 respond very well to EQ, and sound even better of decent amp (Pan Am in my case) and the CX300II doesn't.
Now, if I look back I can say that both HD215 and CX300II were two worst buys I ever made. However if I didn't made that mistake I wouldn't know about it.
Some number of posts I was wondering how does K240 compare to HD215. I had few opportunities to listen to K240, and even though I hate their sound signature, I admit they sound better, cleaner, more detailed. G... HD215 IMHO is complete failure of Senn.Warning: Spoiler! (Click to show)
Edited by koolas - 4/16/15 at 4:08pm