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Hifiman HE400i Review 2020 Revision (Headphone)

Robbo99999

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I finally finished my measurement fixture and got to measuring my 400i. I felt like the left channel had more low-end compared to the right which wasn't very obvious all the time, but would sometimes annoy me, so I was anxious to see the differences.

Measurement infos:
-EQapo active with oratory's preset
-Put headphones on, measure, take off (repeat this 5 times and average the results for accuracy)

Here is the left vs the right response (12th smoothing):
VY12TJj.jpg


And here are all 5 measurements I took of the left channel for those who are interested. They don't vary much, indicating good accuracy and repeatability (no smoothing).
WcLD8kD.jpg


TBH I'm not happy with this. There is an 8db imbalance at 20hz between the two channels. I bought a b-stock, so maybe the original owner knew this and returned it for that reason. I will see if I can get these replaced. If not, I can still eq the channels independently I guess...
I've seen Resolve talk about what happens with planar headphones when they break seal - the subbass disappears but then you get a higher peak in the bass further up the frequency range - that looks very similar to what you have going on there with the right channel. It's possible that the right earcup is not sealing properly to your rig (and maybe not to your ears either based on you saying you noticed an audible imbalance)......perhaps it's worth checking that there's not something "different" about how the pads look / fit / seal on the right earcup.
 

peniku8

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I've seen Resolve talk about what happens with planar headphones when they break seal - the subbass disappears but then you get a higher peak in the bass further up the frequency range - that looks very similar to what you have going on there with the right channel. It's possible that the right earcup is not sealing properly to your rig (and maybe not to your ears either based on you saying you noticed an audible imbalance)......perhaps it's worth checking that there's not something "different" about how the pads look / fit / seal on the right earcup.
It indeed looks a lot like what you're describing. I guess I'm gonna remove the ear cups and investigate. The fixture is just a flat (and smooth) surface and the measurements looked exactly the same (when I took them off and put them on again), so I doubt it's the seal between the pad and the fixture, but it might be that the pad is not attached properly.

Vt55HFB.jpg


9RlpqJB.jpg
 

Robbo99999

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It indeed looks a lot like what you're describing. I guess I'm gonna remove the ear cups and investigate. The fixture is just a flat (and smooth) surface and the measurements looked exactly the same (when I took them off and put them on again), so I doubt it's the seal between the pad and the fixture, but it might be that the pad is not attached properly.

Vt55HFB.jpg


9RlpqJB.jpg
Yes, that sounds sensible, worth checking.
 

peniku8

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Yes, that sounds sensible, worth checking.
I just switched the earpads and will see how it measures tomorrow. I found one bent/slightly damaged plastic tab on the right ear cup, which I might've fixed (I just bent it back into shape with my fingernails), but since they also switched sides now I should definitely see a difference in the next measurements, if this was the culprit. A quick listening test revealed nothing at all, it sounds as before to me, but it's really hard to tell where the sub bass comes from. I'd say the left earcup feels slightly more like a closed headphone than the right one, if that makes sense.
 

Robbo99999

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I just switched the earpads and will see how it measures tomorrow. I found one bent/slightly damaged plastic tab on the right ear cup, which I might've fixed (I just bent it back into shape with my fingernails), but since they also switched sides now I should definitely see a difference in the next measurements, if this was the culprit. A quick listening test revealed nothing at all, it sounds as before to me, but it's really hard to tell where the sub bass comes from. I'd say the left earcup feels slightly more like a closed headphone than the right one, if that makes sense.
Good idea for an experiment there, looking forward to what you find
 

solderdude

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I hope your head is not as wide as your rig. :)
Pads will be compressed more than in reality.

You cannot say anything about the frequency response though.
You would have to make a correction curve to be able to say a bit more about the actual FR.
Looks like the mic is mounted behind a small 'ear canal' given the 6.5kHz resonance that 'canal' has.
 

peniku8

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I hope your head is not as wide as your rig. :)
Pads will be compressed more than in reality.

You cannot say anything about the frequency response though.
You would have to make a correction curve to be able to say a bit more about the actual FR.
Looks like the mic is mounted behind a small 'ear canal' given the 6.5kHz resonance that 'canal' has.
It was a bit of a requirement, since the measurement mic is exactly that length and I did not want the right ear cup to rest on the XLR connector.
I already had to make a custom xlr connector which does not protrude much into the ear cup, to shrink the width a bit. Compromises compromises..!

naFo6xl.jpg


The fixture is not so much about absolute frequency response, as it is intended for channel matching (and it's decent enough to find small kinks and measure distortion).
I thought I could make a correction curve by measuring both my HE400 and my HD650 with oratory's EQ applied, but the measurements of these two already look (and sound) vastly different, it's very hard to find a general direction. I'd have to iterate and go by ear I guess. I'd say the HE400 EQ sounds more accurate to me, the HD650s are still kinda bass-heavy (even when taking the presumably bad seal of the right HD400 earcup into account).
The ear canal is 11mm deep, which I found to produce reasonable results after a bit of testing. Wierdly enough I did not see this resonance in my initial measurements. I can still change the mic position and will see what gives me the best results (the current 11m depth is minimum depth for reapeatability when I take out the mic, but I can modify the pieces to get it further in if needed). There is a rubber ring between the two left pieces, which seals the ear canal. I also wondered if I should chamfer the entrance on the ear cup side, but once I do that there is no going back... Any thoughts? A hard edge might produce artefacts maybe?
 

peniku8

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Won't be possible, because your rig doesn't have the same acoustic impedance as the human ear, as Oratory explains here.
Yea, that's the reason then why the measurements of the HD650 and the HE400 already look very different. And they're both open backs. Closed-backs would probably show an even greater difference (compared to open-backs). But it's still fun to fool around with the rig. For my use case the deviations don't really matter.
 

peniku8

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Yes, that sounds sensible, worth checking.
You're the man! Look at this:

qONVmJl.jpg


Bass deviation is less than a db now, this is great! Interestingly, the wierdness between 1 and 2khz swapped channels now.
Here are two more comparison pics:

AFZP7zp.jpg

As mentioned, the 1-2khz response changes a bit from swapping the pads. Now the left channel looks like the right channel looked in that region before (and vice versa). Btw, is disassembled the fixture (took out the mic), which might account for some of the changes.

Here is the interesting bit now:
zO7LQ4A.jpg
 

GaryH

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You're the man! Look at this:

qONVmJl.jpg


Bass deviation is less than a db now, this is great! Interestingly, the wierdness between 1 and 2khz swapped channels now.
Here are two more comparison pics:

AFZP7zp.jpg

As mentioned, the 1-2khz response changes a bit from swapping the pads. Now the left channel looks like the right channel looked in that region before (and vice versa). Btw, is disassembled the fixture (took out the mic), which might account for some of the changes.

Here is the interesting bit now:
zO7LQ4A.jpg

Yet more evidence that pads, and even how well they're fitted to the headphone, can have a significant influence on frequency response, and so the sound you hear.
 

Robbo99999

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You're the man! Look at this:

qONVmJl.jpg


Bass deviation is less than a db now, this is great! Interestingly, the wierdness between 1 and 2khz swapped channels now.
Here are two more comparison pics:

AFZP7zp.jpg

As mentioned, the 1-2khz response changes a bit from swapping the pads. Now the left channel looks like the right channel looked in that region before (and vice versa). Btw, is disassembled the fixture (took out the mic), which might account for some of the changes.

Here is the interesting bit now:
zO7LQ4A.jpg
Wow, cool, I'm pleased my suggestion of pad issue was the cause of the problem, and that you've managed to fix it! See....there is a use for your rig!
 

solderdude

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I thought I could make a correction curve by measuring both my HE400 and my HD650 with oratory's EQ applied, but the measurements of these two already look (and sound) vastly different, it's very hard to find a general direction.

Yes it is not possible.
Even the rig Amir and Oratory use are not correct in an absolute sense.
They are more correct than most other rigs up to 6 to 8kHz though.

The rig you built, even with a mic flush mounted or with a pinna will not give any correct measurements. The mic isn't suited for this and a hard wooden surface doesn't help either.

What the rig can be used for is imbalance measurements and to determine the effects of modifications or EQ you made referenced to the before or no EQ measurements. Accurate FR measurements aren't a possibility with that mic in that fixture.

Best to discuss things like this in another thread though.
 

peniku8

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I used my measurements to develop channel dependent EQ and smooth out the frequency response and I'm happy with the results.
The differences are really small, but the corrections give the headphones a tad more detail and accuracy. They sound ever so slightly more like my studio monitors now.

tzvtASk.jpg


LwoYUxt.jpg


LY5TG7W.jpg


I did not touch bass nor did I touch anything above 5k since I don't trust the data there/can't interpret it well, but the consistency in the mid to lower treble region was good (also in comparison to the HD650 measurements) and EQ results were great, so I kept the new EQ preset. It's 20 points now...

On another note.. I found that my stock cable is damaged and I don't have high hope on it lasting for much longer, can anybody recommend a replacement cable that's not some unusable audiophile braided snake oil stuff? I couldn't find normal-looking high quality cables on ali express nor on Amazon. Would need it shipped to Germany
 

peniku8

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Been looking for a replacement cable for a while, after my stock cable broke at the headphone connector (and the stiff cable started annoying me).
Long story short, I found and ordered a nice looking cable from Aliexpress, which ran me 11€. It's a braided cable and claims that half of the leads are silver plated, but I don't care about the audiophile stuff, I just want sound at my headphones with a relatively flexible cable that just gets out of my way (which the Hifiman cable was not).
I didn't expect much from a 11€/13$ cable, but man was this a pleasant surprise. It feels as high quality as it looks and is much more flexible than any other cable I had so far. For anyone looking for a good alternative that doesn't cost a fortune, this should be one of the best alternatives imo. Can't say anything about durability, since I've only had it for 2-3 weeks now.
Here is a direct link to the cable: https://www.aliexpress.com/item/1005001642424244.html
I'd much rather buy 10 of these compared to one stock Hifiman cable at 130$ lmao. In fact, I'd perfer this one, even if the Hifiman cable was the same price...
Microphonics exist above the "split", but only really when you bang on the cable. I haven't noticed it transmitting rubbing sounds
 

cheapmessiah

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Was thinking of buying the sundaras this BF but there seems to be no good rebates for it where I live, and the hifiman eu store hasnt posted yet what their BF rebates will be, usually this arent any good tho.

ATM I can get the 2020 400i for 120€ new localy, great price if you ask me, the sundaras + fiio e10k (that i could sell for maybe 40€ since i dont need it or want it) for 350€, and a store-sold refurbished sundaras for 174€, which sounds very attractive but the store only guarantees they work fine, but wont show pictures of it, and on the phone they wont clarify if it comes with original packaging or even the original cable, and thats a turn down for me.

Between the 400i 2020 and the sundaras, I dont think the sundaras are 3 times the value proposition that the 400i offer at 120€ since I was going to EQ them anyways, plus, it leaves me more room to buy the edition XS if it ever gets released in EU.
 

peniku8

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After a long while of thinking and not being very happy with the HE400i headband and thinking about the Sundaras I saw Hifiman's black friday deals today.... But my common sense spoke to me, so I resisted and didn't order a pair of Sundaras. I ordered the HE6se instead...
 

Jimbob54

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After a long while of thinking and not being very happy with the HE400i headband and thinking about the Sundaras I saw Hifiman's black friday deals today.... But my common sense spoke to me, so I resisted and didn't order a pair of Sundaras. I ordered the HE6se instead...
*Thumbs up*
 
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