You have tons of options coming from android if you want better sound, starting from entry level enhancements like a Dragonfly dongle DAC (which I wouldn't use with pretty much any Hifiman headphones) all the way up to a Chord Mojo portable amp/dac and even beyond. If you want to drive more serious headphones properly though, you're going to have to do something, because unless you want to wade into the sea of IEM options out there, most proper full size headphones that are worth listening to need more juice than your android phone can provide. Also, if I had to choose between the HE400SE and the SHR840A I'd take the Shure in a heartbeat. The 400SE have an issue where if the mix is very complex the sound kinds of bunches up, sounds muddy, and you lose the sound stage. The 400SE lacks bass punch which is fine for most music but if you put something like "Who am I" By Beenie man on, you're going to be a sad panda. The 400SE delivers a very relaxed non-speedy sound that is usually detailed and does great work with vocals end electric guitar especially but they run into issues with a lot of music. An example of a ridiculously cluttered track is Champagne supernova by Oasis. On the 840A it still sounds organized but feed it to the 400SE and it just becomes a swamp in the most complex parts.Basically what I'm saying is, the 400SE is not a "This is my only headphone" headphone. It doesn't meet the cut for that. It does a lot of things really well, but it does too many things badly to be your "only headphone" and it's also seriously non ideal to run off mobile without investing $$ into a proper mobile amp. The 840A also gives you several advantages over the 400SE and Grados- it's closed back, so you can take it on the bus and not bother people. It's easier to drive than the 400SE. Buy a dragonfly, and you're going to be good. Also, based on my experience with the SR80 and 400SE and even 400i I can confidently say that the Shure's sound "right" with more music, more often, than either of those other headphones, while also offering better bass. I don't have experience at home with that many headphones long term, but I have listened to pretty much all the major full size headphones at the headphone shops in my city at some point. I don't like talking about most of them though because I have maybe 4-5 tracks each on them and not 3500 like on the stuff I use at home.