[Selbi]

I'm considering to get a secondary headphone to use in combination with my Fidelio X2. Don't get me wrong, I really love those cans; amazing bass, ridiculous sound stage. Perfect for gaming and movies. But it's lacking for music. The clarity is out the window and you get fatiguing very quickly.
 
Since a headphone that does everything the X2 does while also being clearer would cost me a fortune, I was instead interested in simply getting a second headphone to use depending on the situation.
 
Despite having listened to neither yet, I feel like the HiFiMAN HE-400i or the Sennheiser HD 650 could be great, and they're both in my digestible price range of <300€. What do you guys think?

 

[FumblingFoo]

The HD 650 is warm and veiled, IIRC, in addition to having some bass impact, so it might not be a direct opposite of the X2's (haven't heard the X2's so not sure if they're warm or bright). I've heard good things about the 400i's, but I don't recall much about their sound signature (they're frequently recommended in the context of the HD 598's / 600's). A pair of headphones that I can recommend are the Beyerdynamic T90's. They good, tight bass that's far from overpowering, and overall bright headphones and are very clear. I haven't heard the AKG 701/702's, but they're probably good choices too and they get recommended here around the forums.

 

[serman005]

  I'm considering to get a secondary headphone to use in combination with my Fidelio X2. Don't get me wrong, I really love those cans; amazing bass, ridiculous sound stage. Perfect for gaming and movies. But it's lacking for music. The clarity is out the window and you get fatiguing very quickly.
 
Since a headphone that does everything the X2 does while also being clearer would cost me a fortune, I was instead interested in simply getting a second headphone to use depending on the situation.
 
Despite having listened to neither yet, I feel like the HiFiMAN HE-400i or the Sennheiser HD 650 could be great, and they're both in my digestible price range of <300€. What do you guys think?

What do you mean when you say, "The clarity is out the window?" Also, why are they fatiguing to you with music? Is it the treble? The bass?

 

[Selbi]

  What do you mean when you say, "The clarity is out the window?" Also, why are they fatiguing to you with music? Is it the treble? The bass?

 
I've noticed how my IEMs, the Sennheiser Momentum In-Ear, I have substantially better clarity than I would've ever achieved with my X2. When I'm listening to demanding music, such as complex orchestral stuff, it's become an almost nonsensical idea to even consider using my X2 instead of those IEMs (which by the way cost only a third). This is what strikes me as odd and could need fixing.
 
It probably has to do with the treble clarity. The X2 has extremely sharp treble spikes, which both cause clarity loss as well as fatiguing. The bass may also have a factor in the equation.
 
Thing is, the X2 is the first ever headphone I had that makes me remember by the way my ears feel the next morning that I wore them.

 

[Me x3]

HD650 is smoother and more resolving than X2. More natural and microdetailed. Not an opposite, but it might work for you anyway.

 

[Mr Makarov]

I know what are you talking about.
"I've noticed how my IEMs, the Sennheiser Momentum In-Ear, I have substantially better clarity than I would've ever achieved with my X2. When I'm listening to demanding music, such as complex orchestral stuff, it's become an almost nonsensical idea to even consider using my X2 instead of those IEMs (which by the way cost only a third). This is what strikes me as odd and could need fixing."
X2 are good. But not awesome at all. Just good.
I saw you mentioned HE400i and it is a very good option. An upgrade. If you want more clarity, less but much better quality bass, forward, real, natural and organic mids and on top of that a surprisingly detailed sound (much more than X2) - go for HE400i. For me it became impossible to listen to X2 after HE400i.Fidelio X2 sounds wrong, boomy, muddy, and unrefined compared to HE400i. Also, Momentum In Ear are veiled compared to HE400i.
Just my personal opinion. Hope to be of help.