Just heard the T5 3rd gen yesterday and holy moly!! They sounded amazing!
I have had a love hate relationship with Beyer headphones. Over the years I've owned and then eventually sold off a number of beyers (DT990 Pro, DT880 600Ohm, DT1770, T90, T51i, T5p). I can't say that there was ever a beyer that came without problems. In general, Beyers do somethings exceptionally well and others horribly wrong. One of the things that beyer never got correct with any of it's headphone was the tuning. Something was always off (esp the low end).
I think Beyerdynamic has finally struck gold with the T5 Gen3. This is by far the best beyer I have tried. Period. I'd go as far as to say that the T5 is probably one of the best deals in a closed back you can get right now.
I got to listen to the T1 3rd Gen last year and had somewhat similar mixed feelings. The tuning was definitely new with no sibilance and peaks but again it sounded a bit "wonky". The mids were just not right. Anyway, I shrugged them off as "another beyer" and never bothered with the T5. Wrong decision.
The T5 is the most properly tuned beyer I have heard in a while. The overall sound is relatively flat with an emphasis on the low end (soooo tastefully done.....oh ma gawd!!!). The signature is slightly dark but not veiled or constricted. Highs are tame and very nimble. Mids are lush and warm with great texture and resolution. The king is obviously the bass here. Damn! This thing goes low! And not only that, it does this with amazing clarity and definition. It's almost like there's a very high end sub in there somewhere

. Having said this, I don't think it's a "bass-head" headphone at all. Not by a mile. I think this is a very natural sounding set with a lush sound (borderline warm).
The tuning is so good here that I was actually flabbergasted. In a blind audition I would never have guessed that this is a beyer headphone. The only thing that might make someone think that it's a beyer is the detail level. It's on par or better than most upper tier dynamic headsets out there.
I'm really impressed. However I'm also at a loss to find something to compare this to. The Fostex TH900 Mk2 that I own and love is quite different from this. It veers towards an analytical tone: favouring quality over quantity (both ends of the spectrum). The beyer on the other hand is more balanced serving both in equal measure.
I'm still burning in my newly acquired MDR-Z1R (got an awseome deal). I would reserve my views on this comparsion coz I'm still trying to get the hang of the sony's sound.
(Comparing from memory):
The HD820 is another closed back from Deutschland but shares no similarities with the Beyer (except the detail levels maybe). The 820 is highly resolving, anaylitical and techincally proficient with great upper end coverage but sounds a bit dry and thin. The T5 is more lively and natural with better lower end extension. The 820 also had this annoying hardess in the upper mids IIRC , which made it a bit difficult to listen to for longer periods of time. Not so with the T5. It has a very inoffensive tuning.
The closest headphone of a similar tuning I can remember would be the ZMF Eikon. Both headphones have this warmth and lushness that can't be put to words and can only be felt when you hear them. The ZMF and the T5 are completely different in almost everything (build, tech, etc), but surprisingly sound quite similar. However differences would be evident if someone heard them side by side. The ZMF is more of a vinatge sound with a decidedly bassy character and (slightly) hot treble. It's fun and lively (Jazz on the eikon is to die for). The T5 on the other hand is a more mature and modern sounding can with an emphasis on detail and quality of the bass and highs. T5 is more verstaile of the two especially given that the Eikon needs good amping for sure (which is fair considering that the both are targeted towards a completely different audience).
ZMF Verite Closed and Kennerton Rognir could also be valid comparisons since they have similar TOTL pedigree but again the tuning is very different in each headphone and the they are on completely different price tiers.
I don't know if many would share my view but I've gotten used to having a difference in opinion especially when it comes to closed back headphones. Closed backs are very sensitive to fit, seal and pinna size and can sound really different to two individuals depending on the above factors. I had a similar finding with the Neumann NDH20 (everyone hates them; I bought em for the full retail price: yes they're that good), Fostex TH900 and Audioquest Night Owl (not to say that the night owl did not have problems but it wasn't bad sounding as people usually say they are).
For me the T5 has to be the find of the year. I'll see how things go with my Z1R but if it doesn't work I'm sure of what to replace it with

