In this review, I’ll mainly give my impression, together with HD600 and HE-400i comparisons. The HE-500 is driven by the Audio-GD NFB-11.28.
Build Quality & Comfort
The packaging box feels premium. It comes with a Canare 3m black cable, pleather and velour pads (I didn’t use them since the seller had already put Focus-A pads), some manuals and SMC connector replacements parts.
The headphones themselves feel not that bad. Sure, I’ve heard a lot about the old HiFiMAN’s quality control problems, but for the moment I don’t have an issue with them. There are plenty of complaints about the SMC connectors that can be sometimes loose. However, I’ve never had have this issue with my unit. I can use them for days without having the slightest sign of detachment. You might be interested: Review: Audeze EL-8 Titanium The metal articulations look more durable than the ones on the HE-400i. Although the stock pads don’t look that great, the Focus-A pads are soft and comfortable. They are angled and my ears don’t touch the inside where the orthodynamic drivers are clearly visible. The headband padding is very nice and thick but could have been better designed. The weighing scale gave me a solid 540g (without cables), even more than the 502g stated by HiFiMAN.
That simple headband doesn’t really support the weight of the headphones on and around the head well. The clamping force is not hard on my ears so all the weight pressure is located at the top of the headband. Although I don’t feel any hotspot on top of my head, I can be neck tired after 3 – 4 hours of listening to them, just because of the imperfect weight distribution. This is the only issue with the comfort that I had. Overall, they are a reasonably comfortable pair of headphone. The HE-400i has a better headband and weighs 165g less, the HD600 has thicker headband padding and weighs exactly HALF the HE500’s weight. Both are more comfortable than the HE-500 and among the most comfortable headphones I’ve ever used.
Sound Quality
BASS
The HD600 has a light but still present midbass bump but severely rolls off around 70-90 hz. Modern music that has been recorded with emphasis on the bass will sound fine even on the HD600, however, on most other tracks they will definitely sound bass-light or at least slightly under average in terms of bass quantity. The HE-400i has definitely (as a planar of course) better bass response, the midbass is stronger than HD600. It is still a bit too tight for my tastes, and the lows frequencies are very well reached but again very gently. In my view, the bass quantity is what I would consider average, whereas the quality is better than most dynamic headphones. Older revisions of HE-400i (with SMC connectors) apparently had better bass extension. The HE-500’s bass is by far my favorite out of the 3. It hits harder than HE400i across all the bass region, although the bass doesn’t feel really tight. It has a creamy character that I really like and the quantity is really close to my personal ideal tastes.
MIDS
HD600 has very engaging and forward mids that I’ve always loved. Every time I switch from a random pair to the HD600, I’m immediately embraced by their character and tonality. However with time, I started to appreciate it a bit less on some tracks which have high density in the upper-mids region (and lower-treble), lets say 2-5 khz. The HD600 can be a bit piercing and harsh in that region. To me, HE-400i always sounded a bit dry in comparison. But don’t think that I don’t like them! They feel less full-bodied than the HD600 but they still are pleasant to listen, and I don’t encounter any harshness from upper-mids. HE400i’s mids are actually pretty flat when listening with them. HE-500 lies somewhere between the 2 headphones. Its mids has more body than HE400i, especially in the lower mids and 300-1000hz region, which gives them a slightly warmer coloration. The upper-mids are not really brought forward, quantity-wise it’s between the slightly recessed HE-400i and the forward HD600. I really like their mids, to me they are a bit better than the HE400i’s mids, and not better or worse than HD600, just marginally different.
HIGHS
HD600’s highs are excellent to me. Well calibrated, no big sibilances. They extend very very far. The “Sennheiser veil” is definitely a myth nowadays (although I could understand people that find the HD650 (not HD600) a bit veiled since the reduced highs). HE-400i had the most treble quantity among the 3 around 7-10khz. I know my ears and I know that I’m ok with some treble emphasis, thus, I don’t find the HE400i highs sparkling at all. It gives some airiness to the HE400i. I consider other headphones like the DT990 or even the HD800 to have more energy here and to be painful for me for long listenings. Just like the mids, I would say the HE-500‘s highs are between the HE-400i and the HD600. I didn’t experience any sibilance for several hours with treble-oriented music like electro or pop. I even felt that the HD600 has more presence in the lower-treble region, and it’s something that made me feel that the HE-500 is faintly confined on some tracks.
SOUNDSTAGE / IMAGING
HD600 has a correct soundstage and detail retrieval is one of the best I’ve ever heard from a sub-300€ headphone when well amped. The presentation is very engaging and somehow frontal and intimate. I wouldn’t call them laid-back sounding as some people describe them. However, on very mid-centric music, its qualities in the mids may make them sound a bit mist over. HE-400i feels airier and more distant in the overall presentation compared to the Sennheiser. The soundstage is the narrowest of the 3 headphones. However it must be noted that none of them perform well in the soundstage department, and all these 3 headphones are still close on that point. They have great detail and a very accurate imaging. HE500 has slightly wider soundstage than the HE400i, and on par with the HD600. The imaging is excellent and this headphone has a very high ability to deliver speed and instrument separation. Just like the HE400i, the tonality feels laid-back but their just slightly superior technical abilities make them shine a bit better on fast and dynamic recordings.
AMPING NEEDS
The HE-500 is harder to drive than most headphones. The Innerfidelity’s PDF measurements show that it has 47 Ohm impedance at 1 Khz and an efficiency of ~87 db/mW. It requires some power to be correctly driven, around 30% more than the HD600 and 2.5 times more than the HE400i. The newer HiFiMAN and the Sennheiser also need an amp in most situations.
FINAL WORDS
I like them all a lot and is intending to keep all 3 for a long time. The HD600 has a unique natural tonality that I will always love to death, but sometimes I can feel the lack of bass. The upper-mids peak can be fatiguing for long listening sessions, in which I EQ down by 2/3 db the region. The HE-400i has airy highs and tight bass while sounding very natural too. However, I sometimes find them a bit dry in the tonal balance (but much less than DT880 or any other V-shape headphone!). The HE-500 is a warmer HE-400i with stronger bass, slightly fuller mids and reduced highs. I like them a bit better than HE400i for music. They are a good complement to the HD600 since the Sennheiser are very different sonically than any of the 2 HiFiMANs. I still don’t think I would have bought new 700€ HE-500 when it first launched. But now they can be found for 350-400€ used with Focus Pads that improve comfort. Honestly, at less than 400€, I don’t know any open headphones that sound better than the HE-500 for a neutral (but a bit warmish-oriented) headphone. A combo of HE500 (+ HD600) + (another fun or V-shaped or big soundstage can) and you’ll have a trio that covers a lot of things and enjoyment sessions.
