[xLoud]

I am using Audio Technica ATH - M40x and MSR7 with my Fiio X3 2nd gen. I want to upgrade my headphones. I have shortlisted Sennheiser HD 600, Beyerdynamic DT880 pro and AKG K7xx. I am bit confused which one to buy. I prefer neutral sounding headphones. I am going to buy it on black Friday hoping I will get some discount. Hd650 is out of my budget considering its current price.

 

[PurpleAngel]

I am using Audio Technica ATH - M40x and MSR7 with my Fiio X3 2nd gen. I want to upgrade my headphones. I have shortlisted Sennheiser HD 600, Beyerdynamic DT880 pro and AKG K7xx. I am bit confused which one to buy. I prefer neutral sounding headphones. I am going to buy it on black Friday hoping I will get some discount. Hd650 is out of my budget considering its current price.

 
Your two current headphones are fairly easy to drive.
Where as the ones your looking at buying are more power demanding,
While I'm sure the FiiO X3 Gen 2 can decently drive them, you might consider getting something like a FiiO A5 headphone amplifier, help bring out the headphone's best.
Just an option to think about.

 

[xLoud]

I will definitely buy Fiio A5 as soon as it is available.

 

[Monsterzero]

   
Your two current headphones are fairly easy to drive.
Where as the ones your looking at buying are more power demanding,
 

+1 on this,especially for AKG K7XX.

I have owned all three of the headphones mentioned....all three are nice headphones,but the HD600 has the smallest soundstage of the lot,which may or may not be an issue for you.

If I were to be forced to live with just one of these headphones for all types of music it would go like this:

AKG K7XX>HD600>Beyer DT880

That is based upon the fact that i like fast/heavy rock/metal and the HD600s are rather dull for that type of music.

I will also mention that of the three the AKG K7XX is IMO the weakest when it comes to build quality.If youre prone to tossing your headphones into a backpack and piling stuff on top of them,or not really interested in handling headphones with great care,you might wanna cross the AKGs off your list.

Comfort: all three are nice to wear,but the AKG is the most comfortable headphone ive ever worn.

Lots to think about and trade offs to consider.

 

[xLoud]

I do not listen rock/metal that much. Mainly I like pop, classical music.

 

[Monsterzero]

I do not listen rock/metal that much. Mainly I like pop, classical music.

Pop does not require soundstage to sound the way it was intended.

Classical does.