First time posting to this thread. I'm giving the HiFiMan Sundara a go for a few days with the Lyr 3 / Mimby. (Normal headphone is the ZMF Eikon.) Someone loaned them to me, so they'll be going back at the end of the week.
Initial impressions:
It lacks sub-bass. It's not terrible, but EDM fans are going to be disappointed. Even rolling in some different tubes (like the KenRad VT231 black plate / clear glass) doesn't really help this much. I don't use EQ much, if ever, so I can't comment on how it responds to that.
There is a detail veil to this, and a slight treble etch. Similar to the HD650 veil on a bad audio chain, but this one isn't getting better going to better gear. (Lyr 3/Mimby to BW2/Gumby.) In short - it lacks on micro-detail quite a bit. For example, no matter what tube I used in the Lyr, I couldn't get these headphones to bring across the hum of Stevie Ray Vaughn's Marshall stack on his track "Tin Pan Alley". It gives such character to the song, and it's just missing on these headphones. It is readily presented on the ZMF Eikon. Another track where detail is glossed over is Rebecca Pidgeon's "Spanish Harlem". If I recall correctly, the entire band and Rebecca recorded that track together in the same room in the studio. You can hear the bass player lift the upright bass and reposition it in the recording, as it makes a distinct 'clack' early on in the track. Right before the drummer starts playing, you can hear him pick up his sticks. None of this was audible on the Sundara. D- to the Sundara on detail retrieval. It would be a complete F were it not for cymbals being fairly close to natural sounding with a adequate amount of decay.
Imaging is rather hazy and indistinct. Staging is 2 dimensional. It presents a very in-your-head, blob like stage.
The ear pads are uncomfortable. I'm bald, and find them hot and itchy after several hours. They are also too small. I have to shoehorn the top and back of my earlobes into the ear holes. This is a personal pet peeve of mine - I don't like it when pads touch the ears.
The stock cable is utter crap. It feels like two of the smallest headphone wires ever used to connect a transducer were sleeved in some flimsy fish tank tubing. It is rubbery, and springy, and while it doesn't resist bending much, it loves to spring back into a straight line. It also gets to the point where it stops bending, and it just kinks. It's just awkward. Add to that the 90 degree 3.5mm TRS plug on the amp end and you have one of the worst cables I've ever come across from an OEM. Re-read that . I said 3.5mm... as in, the little plug, not the standard 1/4" TRS plug. These are open back planars. Who would be dumb enough (other than Raif at InnerFidelity) to take these on the go?! I've met some bad cables before, but this HFM cable makes them look like top end Nordost cables. It is that bad. To my knowledge, HFM didn't even have the decency to include a 3.5mm to 1/4" adapter, as I had to use my own.
On the other side of the coin... They are light. The headband is fairly comfortable. They seem better built than other HFM headphones I've tried. (HEX, HEKv2, HE6, etc.) By that I mean: It doesn't feel like I'm holding a 3000 year old historical artifact that is sure to crumble to dust at any moment, and if it does I know I can't afford to replace it.
Other than the lack of sub-bass, tonally, this is a good sounding headphone. Something in the lower to middle-mids do sound a wee bit recessed, but the rest of the FR seems nicely done. Treble is clear. I've not had a sibilance issue, even using brighter tubes. Cymbals sound decent, as stated above. Vocals seem well placed in the FR - neither over emphasized nor recessed. I can see quite a few people really enjoying how these sound.
In short - Treble heads and bass heads need not apply. They're kind of a different flavor on the HD650 in some ways. The Sundara will have a slight edge in treble extension, but they don't scale very well with better sources like the HD650. I feel the HD650 has more mid-bass impact. The HD650 does mids better. HD650 does detail retrieval better too.
VS the Eikons, the Sundara are very much not good.
Enjoy.
