I currently have the Sony MDR-7506 and the Grado SR80i. I love both of these headphones but I am now starting to see the limitations of them both. I love the fact that they both have a flat response and provide an accurate reproduction of what the artist intended the music to sound like. Of the two the Grado are definitely my favorite. I love how clear they make everything sound. But I am finding that both the Grado and the Sony are a bit harsh in the highs. Sometimes they hurt my ears. I am looking to upgrade to something with a closed back design so I don't bother my wife, that offers a flat response, sounds clearer than both the Grado and the Sony and has about as wide a sound stage as you can get with a closed headphone. At first I was looking at the Beyerdynamic DT770 Pro in the 80 Ohm flavor but I have heard that these are great if you are looking for some bass headphones. I am not really a bass head, I am all about accurate, clear reproduction. I also looked at the Denon D2000 but it seems since they have been discontinued, their prices have skyrocketed. This had lead me to look at the Sony MDR-1R. The Sony MDR-1R is currently my top choice but this is only based on marketing material and limited reviews here and elsewhere so I have to take it with a grain of salt. Do any of these stand out as a good upgrade or is there another headphone that I am not considering that may be a batter fit. Some more info: Source is a Macbook Pro and an iPhone. Currently no headphone amp. I listen to mostly classic rock - Cars, Led Zeppelin, The Who, Pink Floyd, etc... I also listen to Trance, down tempo and ambient electronic music. This comprises about 90% of my tastes in music. I will mostly be listening at home so portability is not so important. I will likely keep the Grado and am more looking to upgrade the Sony MDR-7506 unless there is something that will blow them both away. Thanks.