[sulachhan]

Currently i have 14 headphones from entry level to mid level (IEM,on ear,and over the ear) .I am used to  basshead  headphones(XB500,Koss porta pros, jabra revo and Hisoundaudio Wooduo 2) to entry level  audiophile level  headphone(Sennheiser hd 598).I am used to the expansive soundstage and clarity of hd598 and at the same time deeper lows of XB500 and wooduo 2s.Now i am leaning towards the next level of sonic experience and following 100s of reviews from headfi,wirecutter,innerfidelity,cnet,experts reviews,pcmag and dozens of other sites i have come to stick towards two headphones 1.HifiMan He 400 (currently 300 euro in Finland) 2. Nad Viso HP50( 250 euro). Comfort , design and build quality does not matter to me,what matters the most is sound.I have not tried them so my sole decision will be based on the recommendations from the users who has tried these headphones.My next question is if it is going to be an remarkable upgrade from senn. 598.? How do you compare these with the soundstage of senn. h598 ?  my budget is around 400 euro and if you can suggest me more prefarable cans within my budget which is better than these two?.Every kind of recommendations are welcome.