Even from the brand new Astell&Kern, the volume has to go quite the way up but the SE100 doesn’t really alter the sound in any way. The SE100’s sound signature is somewhere between that of the AK70II and the SP1000. It’s not as all as warm as the AK70ii but it more has the SP1000’s tonality, yet it doesn’t perform at the level of the SP1000. You get a cleaner sound with just a touch of smoothness and for me this works very nicely with the Sundara. You don’t get increased bass, mid body or softer treble, the SE100 has no impact on that, it just makes the overall tonality a little smoother but not by too much. The real Sundara is what you can hear here.
The Cayin N5ii actually is a more neutrally tuned mid-fi DAP and beside the added bass and more mid body, it doesn’t influence the Sundara’s sound in any other way. A fast pace and clean and clear sound from top to bottom is what the N5ii delivers. There’s never any harshness on the top end but the musicality level is a bit lower on this one.
The portable source I love the Sundara the most from is Chord’s little Mojo. The Mojo feeds it with all the detail and you get a clear, clean and precise, fast sound with an excellent sound stage width. The Mojo doesn’t add smoothness or body to the Sundara but it makes it so musical sounding which is funny as that often is what I feel the Mojo lacks. This combo however magically works and it makes the neutral and linear Sundara sound engaging, precise and musical. For some the treble might sound a little too lively, but I quite dig this setup.
The Feliks Audio Euforia is the TOTL amp of Feliks’ product range and I really love it. It has great dynamics, speed and precision and it for a tube amplifier actually is tuned in a more neutral way. Euforia doesn’t add a lot of warmth but it’s very clean and detailed and a lot more musical then that Mojo combo I raved about a minute ago. That musicality and warmth probably comes from the set of Tung-Sol 7236 I have in there for the moment. Anyway, a combo that delivers precision, detail, clarity and musicality. This is the best I’ve heard the Sundara sound and it has the widest sound stage but mostly the deepest with the best layering as well. This is excellence.
The solid state Acro L1000 from Astell&Kern is the amplifier I’ve been using at my office most of the time but the synergy with the Sundara just isn’t there. The L1000 is neutral and flat tuned itself, with a lot of precision, detail and clarity, but it adds it even more to the Sundara to the point that it becomes too much. I honestly don’t get any kicks out of listening to this combo. I like both units separately but together they for my ears just don’t work well together. I love the Audeze LCD-MX4 on it though, and that’s a more neutral tuned studio headphone as well.
I was very interested in listening to the Hugo and Sundara combo as the Mojo is doing such a great job with it. Personally, as you probably already know, I’m a much bigger fan of the Hugo devices, so I was expecting a lot. The extra advantage you have here is that the Hugo allows you to play with the filters and cross settings but in the end I don’t find the pairing as magical as with the Mojo, or maybe that is because the Euforia pairing just is so incredibly good.
Because of the price setting, it’s generally regarded that the Sundara could be the replacement of the HE-400i but at the same time there never was a successor to the HE-560 either… For me this isn’t the HE-560 replacement though, and I still hold that headphone higher in regard. In fact, I really like both of these headphones a lot, so the Sundara is up for a tough comparison
The Hifiman HE-560 has the swivelling cups and although the pads touch your ear a whole lot more, this still is the more comfortable headphone to me even though the Sundara probably has the best and longest lasting build quality. Sound-wise the Sundara sounds more neutral than the smoother sounding HE-560 but if we’re looking at the HE-400i and the HE-560, than the later one is the one that comes closest to the Sundara’s sound. In my opinion they’re quite different though. Some would probably describe the Sundara as a colder sound headphone or the HE-560 as the warmer one (though it isn’t really warm). The HD-560 is also neutrally tuned, yet it just has a tad more smoothness and emotion listening to it. Bass goes deeper and has better layering if you ask me, especially when hooked up to a full sized desktop tube amp. The mids is where you find that emotion I just talked about and the vocals sound warmer and more natural for me as well. The upper mid section and treble section however is wider, more detailed and far more energetic on the Sundara. If you want the most neutral sounding one with technically the best upper mids and treble, go for the Sundara. IF you wan that touch of smoother and a better low end, the HE-560 still is the one for you.
The HE-400i has the exact same headband and pad mechanism of the HE-560 and as such I prefer this headphone comfort-wise as well. The same goes for the HE-400i as for the HE-560 though, and that is that the Sundara is better built, certainly for the long run. Sound wise the HE-400i of course isn’t neutrally tuned in any way. You get bigger bass body and an overall more present low end, including lower mids. The mids section actually is thicker sounding everywhere and the treble is less clear, precise and extended, yet softer. It’s like the more fun and less neutral version of the HE-560 and it’s completely not what the Sundara is: neutral and linear. The Sundara is the HE-400i replacement? Oh no, impossible.
I actually was sad to learn that Hifiman is discontinuing the these two excellent sounding headphones. They’re still available in the online shops though, and if I was you I’d get one before they run out.
Another headphone in the same category and with the same technology is the Audeze EL-8 with the open back. Now in general I’m a big Audeze fan but the EL-8 never did anything for me. Compared to the linear Sundara the EL-8 doesn’t sound as coherent although part of the EL-8s mids are quite good. The Sundara is the more neutrally tuned headphone of both but if we start with the bass then we see they both have the same kind of presence. The difference here is that the Audeze goes lower and is a bit slower where the Sundara is faster, tighter and flatter. Bass body wise, there not that different however. The vocals on the Sundara sound more realistic and natural where they quickly start sounding smoother and warmer on the EL-8. The upper mids and and treble technically are far stronger in the Sundara. They carry more detail, precision, clarity and extension. After all these years I have become less critical for the EL-8 but I’ll still happily take the Sundara over it any day, even though they’re not that much alike.
I was surprised with how Hifiman tuned the Sundara, especially looking at the fact this initially was considered as a replacement for the excellent mid-fi HE series discussed above. It however is nothing like that and Hifiman went for a flatter, even more neutral and linear tuning instead. Technically the mid-fi Sundara scores very high and its upper mids and treble section really are something else.
The Sundara’s more neutral and linear tuning might not be for anyone but this tuning was intentional and Hifiman did it excellently so. For my personal taste the Sundara can do with a little extra amplification to sound its very best and then my choice goes to the Mojo and the Euforia. That doesn’t mean it doesn’t sound good powered directly from a phone or a DAP, but you will see the volume going up.
In the end, if you’re looking for this type of sound, then you can’t go wrong with the Sundara. For the price it is going for it is very impressive on a technical level and the build quality also is as good as it gets. No, don’t expect HE-1000 performance or a sound like that of the HE-400i/HE-560 as you will be in a for quite the surprise. For me the Sundara’s tuning looking at the Hifiman Line-up is unique and it’s impressive to see that the R&D Hifiman is doing, is trickling down to the lower levels. One can only applaud Hifiman for that.