[bbuj]

which one you guys recommend? why?

 

[AhokZYashA]

M50, i prefer punchy bass and its what the M50 are capable of

 

[tdockweiler]

Both are good. There's a ton of threads on this.
 
Get the m50 if you want more bass and a headphone that's slightly less detailed, but has a more comfortable fit. I don't find it all that neutral, but it's still pretty good. This would actually be better for longer listening sessions over the SRH-840. Soundstage is pretty poor even for a closed headphone. Vocals are so-so, but I wish they were a bit more forward.
 
Get the SRH-840 if you want a more neutral headphone with a lot of detail, but nothing excessive. The highs can be fatiguing for me at about the 2 hour mark. These are huge and don't fit that well on my head, so I had to sell them and downgrade the overall sound quality a tad and get something I could actually wear comfortably (M50). Possibly the best headphone in the world for  "Imogen Heap".
 
I'd only suggest getting the SRH-840s if you can find them under $150. They are not worth $200 to me. Even for $150, that's a bit high. These would be a good deal for $130.
 
BTW the bass on SRH-840 is good enough for me, just check the charts and you can see that it definitely has a lot of bass, but some people may still find it disappointing.
 
If you want even more bass (then even the M50) get the Shure SRH-750DJ. I hated these headphones though, but a lot of people prefer them over the 840s.
 
None of these had my perfect sound signature, but both are very good and you can't go wrong with either of them.

 

[Mo06]

I have had the Shure SRH 840s for a few months and am very pleased with them.
 
VERY comfortable for my big head, build quality is excellent.
 
As for the sound, well tastes differ, but I do think they present a pretty accurate version of what the recording engineer was trying to achieve, and that's the bottom line for me.
 
Isolation from the outside world is good, not perfect, but I can't hear the TV playing in the same room, which is what I want.

 

[Mo06]

Oh, and I paid €129, online here in France, which seems pretty reasonable.

 

[kingtz]

The SRH840s have plenty of bass - at least they're good enough for me. It's just not the boomy, headrattling bass that mimics being in a club or disco.
 
If bass is a very high priority on your list, then get the M50s, otherwise, I'd recommend the Shures. As for build quality, just comparing the two phones at a store, I found the 840 to be much sturdier and that it uses higher quality plastic than the M50s. I didn't like the feel of the M50s and they felt more cheaply made to me. That was my first impression when I walked into the store knowing nothing about their sound signatures.

 

[thegatekeepers]

I bought the M50 instead of the 840 a month ago after trying them out in a store.IMO I think the M50 has much better building quality then the 840. I just didnt like the cable sticking out next to the ear cup, I almost certain you can early break them if you take them on the go (keep that in mind, Shure has bad reputation in cable quality). 
 
I personally prefer the M50 in sound wise too although I think they are very close match, M50 has far better base, deeper, powerful but not over. 840 its better in clarity. It really depends what you like in sound.  

 

[EternalEmpire]

You should find this article useful:
http://www.headfonia.com/closed-cans-shootout-m-50-esw-9-t50p-hd25-1-beats-studio-srh-840-srh-750dj-k181dj-and-dj1pro/
 
It's a comparison between quite a few closed headphones in a similar price range, including the M50 and SRH840.