AKG K702 is open and has replaceable cord, very important. K601 does not have replaceable cord, but you can look around and buy two for what one K702 costs, so the lack of replaceable cord isn't an issue.
DT880, latest version, may require some midrange boost, but it is monitor quality and very comnfortable. They sound rather open.
The AKG HEARO 999 is monitor quality and wireless as well. Long discontinued but you may find a used set with the spare headset. They were packaged with two headsets at a special price when being cleared out of inventory. You get a wired headamp that is perfect for AKG cans and you get a good quality DAC and some useful signal processing in the bargain.
You can change the sound of full size AKG cans by switching from velour to pleather earpads. I have one 999 headset fitted with pleather and the other one with velour. The pleather earpad gives more of an upfront K601 sound and the velour earpad gives more laid back sound with less midrange and more prominent bass. Sort of like if you changed out leather furniture with soft padded fabric furniture in your listening room.
Grado isn't comfortable enough for me to consider for longterm monitoring use day after day.
The HEARO 999 digital wireless is probably the flattest sounding cans I have ever used. The DT880 is midrange recessed and the K601 is midrange forward, but neither one is by much.
I was a longtime Sennheiser user, but I decided that their cans had a pleasant coloration intended to impress people to make lots of sales. Still, those who had only used cheap cans were impressed when they heard them.
Grado has some build quality issues. 3 out of 3 SR200 sets had manufacturing defects when I inspected them before buying back in 1995. The third set had the defect visible when I got home with it and looked very closely. Grado customer service said go ahead and use them and if they broke where the crack was at, they would replace them. Well, they never completely broke, but I never used them much because of the comfort issues. Mainly used the Sennheisers until they finally broke, then I went looking for new cans and got Beyerdynamic and AKG cans. AKG is my favorite now, 999 and K601.
I haven't owned Audio Technica, but they should be considered if looking for open cans.
Stay away from super expensive audiophile cans. Almost zero recording engineers use them. You can EQ out a set of cans you otherwise like by listening to a lot of recordings. If the bassy ones sound bassy and the bright ones sound bright and the midrange sounds clear and natural on good recordings, then you have a good set of cans. Not enough high end cans get sold to make them value for money. You pay 3X for a 10% improvement, and you should spend the extra money on 2 more sets of similar midrange priced cans so you can have different cans for different use.
The DT880 sounds more flat when you use reverb surround mode on the 999 base transmitter and volume is moderate. The K601 sounds more flat when surround is off and volume is high. The 999 wireless cans sound more flat in other situations. The DT880 sounds more flat out of my cheap CD player phone jacks. K301 beats all my higher priced cans straight out of my computer audio monitor hp jack.
Even the highest priced cans seem to not be able to do it all, so 3 or 4 midrange cans that have different complementary character work better for me. One of them seems to work very well in any situation.
