Next comes the moment of truth when the headphones are plugged in and the HE-400i’s do not disappoint. On the contrary, they surprise with a sound that in very many respects closely parallels that of HiFiMAN’s new HE-560 (the sonic ‘family resemblance’ is unmistakable). But here’s why I chose the word, “surprise”. The original HE-400 was and is a very good headphone, but critical listeners who heard both the original HE-400 and HE-500 side-by-side would probaqbly concede that the performance gap between the 400 and 500 was a fairly significant one (the 500 offered marked more neutral voicing and dramatically better resolution). The surprise I alluded to centres on the fact that the new HE-400i actually sounds quite a lot like its almost twice as expensive big brother, the HE-560. Now please don’t misunderstand me. The HE-560 is, without a doubt, the better headphone of the two and as with the predecessor models the differences centre on tonal neutrality, resolution, and focus—all three being areas where the HE-560 enjoys a clear-cut edge. But with that said, let me also point out that the perceived ‘gap’ between the HE-400i and HE-560 is much narrower than was the gap between the HE-400 and the HE-500, which is encouraging news for those shopping for mid-priced headphones. Moreover, and this is a somewhat tricky observation to put forward, the performance differences between the HE-400i and the HE-560 only become fully apparent when using upper-tier headphone amp/DACs (with good but not great amp/DACs the sonic differences between the headphones are still there, of course, but they are much less apparent). This, too, is good news for headphonistas on a budget.
Another piece of good news is that the HE-400i is significantly easier to drive than the HE-560, so that in a pinch one might even drive it directly from a smartphone or tablet. I tried the HE-400i with both my Samsung Galaxy S5 smartphone and my iPad and got OK but not great results with the phone and slightly better (but still not great) results with the tablet. My advice: Pick up a good portable amp/DAC to use with the HE-400i; they deserve it (hint: the HE-400i pairs beautifully with iFi’s also affordable Micro iDSD portable amp/DAC).
In terms of sonic character, the HE-400i offers reasonably smooth, wide bandwidth frequency response, but with small traces of midrange forwardness vis-à-vis the somewhat more neutral-sounding HE-560. Still, the overall voicing of the two models is strikingly similar, which I consider a point in the HE-400i’s favour. The HE-400i offers very good levels of detail, transient speed, and overall nuance, though with a top-shelf amp/DAC it becomes clear (pardon the pun) that the HE-560 is a smidgeon better in all three respects. Further, the HE-400i offers the traditional planar magnetic virtue of easygoing coherency of the sort that lends desirable qualities of top-to-bottom evenness and consistency to the proceedings. I suspect that the HE-400i will be all the headphone that many music lovers will ever need or want and it is one that, while certainly not cheap, will also not break the proverbial bank.
One point I probably cannot overstress is that the $499 HE-400i is good enough that one might instinctively seek to compare it to models costing $700, $800, $900, or more. The HE-400i might win some and lose some in those head-to-head comparisons, but I feel confident in saying that—win, lose, or draw—the HE-400i will certainly not embarrass itself in direct competition with more expensive headphone fare, which is pretty remarkable in light of the price differentials involved. For these reasons and many more, I suspect the HE-400i will become a top-seller for HiFiMAN, as was the HE-400 before it.
I still have much to learn about the HE-400i as I begin work on a full-length review for Hi-Fi+. Among other things, the headphone still needs a lot of run-in time (HiFiMAN recommend giving the headphone 150 hours of run-in) and there are many comparisons yet to be made. Thus far, I’ve compared the HE-400i to the original HE-400, the HE-560, and to Oppo’s PM-1. But, in the course of my upcoming review listening, I hope to compare the HE-400i to Final Audio’s Pandora VI and—if I can get my hands on a sample—to Oppo’s soon-to-arrive, cost-reduced PM-2 planar magnetic headphone. Those should prove to be enjoyable and eye-opening comparisons, to say the least.
In the months to come, watch out for the Hi-Fi+ review of the HE-400i and in the interim, may I wish you all happy listening.