Yes, they are bright, however, that kind of behavior can be fixed with the proper materials (a piece of 2-3mm thick felt in front of the drivers). The 681 Evo have such a piece of felt to reduce the treble energy, turning it into a dark can, Solderdude found a pair of replacement pads that reduce the bass energy a good 10 dB, turning it into a considerably flatter pair.

A good EQ should not change the sound for the worse, however, with the boosted highs come an increase perception of details and ambiance, so yes, in a way you will percieve less of that, but they should sound more natural and properly balanced with the rest of the spectrum when properly EQ'd. On amping, I couldn't say, depends on a lot of factors, however, 56 ohms is not a lot, they should play loud enough from just about any source.

Hearing damage comes from a high SPL, so watch your volume and rest your ears once in a while.

Just stumbled upon this site and I am a newbie when it comes to these high end headphones. I recently decided it was time to upgrade from my Sennheiser HD 239 that I got for 40$ off ebay. I have been doing some research and have found that I like the Beredynamic DT 990 but is really out of my budget. I am looking to spend about 500$ in total. So I want to know if there is any alternatives to the DT990 that have the same if not better specs for a cheaper price. I also heard that I needed an amp to power these things and I have stummbled upon This. Will this be strong enough to power my headphone? Is there a more budget friendly amp that is still portable? I saw This but it seems to get mixed reviews. Does the headphone come with all the cables that I need or are there any specific cables that I will need? Are they expensive or relatively cheap compared to my budget? Oh forgot to mention that I enjoy electronic music, such as dubstep, chillwave and drum and bass as well as metal and rock (see Mastodon). Thanks in advance to anyone that helps out!