I'm honestly freaking out a bit because my first full EP is due to the label by the end of next month and my current mixes sound like absolute mud when I play them in the car or on my phone. My home studio here in London is basically just a spare bedroom with zero acoustic treatment so I have to rely 100% on headphones for the final polish. I've always heard Sony is the industry standard but I'm stuck between a few models and I dont want to waste my money.

Right now I'm looking at:

• The classic MDR-7506 (everyone uses them but are they too harsh for long mixing sessions?)
• The new MDR-MV1 open backs (they look amazing for spatial audio but they're pricey)
• The MDR-M1 closed backs that just came out

My budget is around £350 max and I'm really worried that if I go with the 7506s I'll end up with ear fatigue after two hours but if I get the MV1s will the open back design leak too much if I use them for tracking vocals later? I need something that is actually flat and honest because I cant afford to have another mix fail the car test. Which of these is actually going to help me get a professional master done in a month? Is it worth the extra cash for the MV1 or should I stick to the classics...