For the last couple of years,I've been searching for the perfect portable headphones.I have been looking for sound quality that I get from my home setup but in a portable package.I know I can very good sound with portable amp/DAC's combo,but frankly I didn't really like the extra bulk and components.Although I did try the Audioquest Dragonfly v.1.2 with a Apple lightning to USB adapter.Which sounded pretty good,but uses way too much power from my iphone.I've gone through a number of headphones and IEM's.Including the Philips Fidelio S1 and S2,Sennheiser IE80,RHA MA750i and T10i,JVC HA-FX850,Bose SoundTrue Around-Ear headphones,Beats Solo 2,and the V-Moda Crossfade M-100's.These Philips Fidelio M2L's have the best sound I've found.Build QualityBuild quality is excellent.The M2L's are very similar to the M1's and M2's.Styling is understated,with real leather surrounding the headband.Volume dial is located on the right earpod,along with a multifunction button which can be used to pause,FF,RWD tracks and also answer calls.Protein leather cover the memoryfoam earpads.Which are very comfy.The cord is a little stiff though,but not too bad.Headband adjustment seems a little limited also.I have a average size head(size 7 1/4" hat size)and I have to adjust the headband one click in from it's maximum size.So people with larger heads may find the headband might not have enough adjustability to fit their head.FunctionsVolume can be adjusted from either the phone or using the volume dial on the right earpod.Also the entire right side cover is a multifunction button.Click once to pause current track.Double-click to go to next track,triple-click to go to previous track.You can even answer calls even though there is no inline mic.You just click the multifunction button to answer calls,and use the mic on the phone to speak into,just as if you're talking using the speakerphone.Sound QualitySound quality is excellent.The external DAC and AMP really do make a difference.Clarity is excellent,with no harshness in the highs.The midrange in particular is wonderful.Tonal balance between the high and mids is right on to my ears.Bass is powerful and deep.In fact,the bass was almost too powerful at first.When I first got the headphones the bass was a little overbearing compared to the mids and treble.But as I played them for 100+ hours the highs and mids have really opened up and the bass has tightened up and is more articulate.These headphones do not have a flat frequency response though.Bass is accentuated,which is what I prefer.I would say the bass response is very similar to the RHA T10i IEM"S,except the high's are much better on the Fidelio M2L's.I would say these phones are excellent with modern genres of music like hip hop,R&B,pop,EDM,etc...I'm not sure how they would sound with genres like classical or jazz as I don't really listen to those genres.While they have a strong bass signature,it is not as high as say the V-Moda M-100's,JVC HA-FX850's,or the Sennheiser IE80.Overall I'm very happy with these headphones.And I think my search for the ultimate portable headphones has ended...for now atleast.