Pros: Fantastic midbass and bass; Supremely comfortable, well-built, strengths far outweigh weaknesses.
Cons: The Active Mode is awful. Rolled off on top? They sure are. But that suits me.
A proper introduction should be in order; I am by no means a sound engineer, or even barely claiming to be. The best pair of cans to sit atop my head for any period of time has been a set of Sennheiser 202-II's, so I should be easy to impress! And goshdarnit, with this set, I am. I am playing my UE6000 through a Audioquest Dragonfly, primarily listening to Spotify Premium streaming at 320kbps or through FLACs.
So, in all ways, you can consider this to be my little froggy flop into a bigger pond. Better music, a better DAC, and a better set of headphones. So, with that info, I can only give you the impressions and improvements that I've noticed in my everyday listening.
I am nothing but a man who loves a good thwack of a bass guitar. Geddy Lee, Geezer Butler, Flea, Victor Wooten, Burton and Newsted, Wolstenholme, Novoselic, Ellefson and especially one Les Claypool all come to mind in terms of names. The 70's, late 80's and early 90's are all sweet spots of rock n' roll for me, whether it be under a level of grunge or displayed in grandeur with the NWOBHM. Other bands and other genres must flow through these headphones, but I am always one to give this pair of headphones it's healthy dose of bass. It hits with a thwack, an impressive and controlled sound that brings a smile to my face on songs like Tommy the Cat (via Primus), Malignant Narcissism (via Rush), Around the World (via Daft Punk), and best of all, best of all, does Would? from Alice in Chains extremely proud.That bassline punches along like the Monster it is, without forfeiting the rest of the song. (Afterthought: Super honorable mention goes out to Hyper Music from Muse.)
That, to me, is the greatest thing about the UE6000. I am by no means someone who means to do mids or highs harm to have my wall of bass; I hate huge sonic booms and massive rumbles overcoming the rest of the music. Bass grooves and drives the song along, rarely ever needing to take a front seat. These mids are superb, as almost all vocal sections are incredibly clear, with no bleeding or mixing involved. I couldn't tell you if they're U or V-shaped, but they often match the occasion of what's called for. They aren't 'forward', and the song really dictates where the balance between the bottom and mids are; Metallica's bass player won't suddenly come to the front with these headphones, because Metallica has rarely ever worked that way, and shouldn't. The same goes for Les Claypool's serenades; Les' voice often simply plays along in a smaller role providing a different tone to contrast with his bass licks, as they should be. (God, I'm just trying to say there's a good balance here! Damn you, language!)
And well, that brings me to the highs. To be honest, highs are usually never a priority for me. The term 'sparkle' could slap me across the face and I still wouldn't really understand the true value of it. The solos of all the greatest string players, whether they be lead guitarists, violinists, or whatever they may be could serenade, shred and sing to impress me, and I'd still say, "Right, that was nice, onto the next bit!" Are the highs of the UE6000's a bit rolled off? Yessir, they probably are. They can sometimes come in 'under' the mids when it seems like they not ought to, and sometimes, that can be a bit of a shame. Still, for a headphone in this range, this is the perfect area to forfeit a bit of performance for my tastes, and I would rather have them be rolled off rather then come anywhere close to 'sibilant'. Too much bright and brittle will make me run screaming away from any headphone, and the UE6000 never threatens such a thing.
All in all, these big old Logitechs appeal massively to me. They play and stomp through my favorite genres without ever becoming deficient in any genre of music. The worst you could call them is 'very, very good' and for me, they range into 'great'! I don't know where I could go from here to possibly spoil myself more than I already am. These are incredibly comfortable headphones, even if they are way heavier then what I've been used to. 32 ounces of driver and headphone far outweighs the 5 ounces of HD-202 that I had, and it was quite an adjustment for a little bit of neck fatigue. There's an incredible amount of competition surrounding the Logitech sets, from Sennheiser, V-MODA, Beyer, Audio Technica, and the rest of the field. I'm largely ignorant to the sounds of the rest of the field surrounding my headphones, but I'd be willing to bet that few would be disappointed with a good set of these phones.
And hey, if you're here, you've either skipped the article or finished reading the darned thing. In either case, thanks for taking a look and try a set of these headphones on if you get the chance. I don't think many will walk away disappointed. (And hey, if my musings make any sense to you, maybe you could comment on what headphones typically represent the type of sound signature I myself like out of the UE6000's, at a higher or lower price point? I may have taken a dive into the pool with these phones, but some of y'all are on the crazily deep end of the pool with even better equipment. I'm wondering if I'm crazy as you are.)
P.S. This review is completely based off of my impressions of the Passive Mode. The Active Mode somehow trips up everything good and sacred about the UE6000 and "actively" makes it horrendous. The bass sound becomes every detractor you can think of; 'Boomy', muddy, thudding, a wall of noise that betrays how excellent the passive mode is.