Hifiman HE6se Review (Headphone)

[thecoolerplayer]

Topping G5 can output at least 5-6V without clipping to 50Ohm according to ASR review. (according to L7Audio it's beyond 6V).
HE6SE V2's sensitivity is 91dB/V. So even 4V output can give you 91 + 2 * 6 = 103dB.

Thank you for your reply. However, the sensitivity is 83.5dB at 50Ohm, although the ASR review measured it at 64Ohm. So assuming the worst case of sensitivity being 83.5dB at 64Ohm, and say I want to listen at around 105dB instead of 95dB - how does that change things?
Also, apologies for this question but could you tell me or point to a source which can teach me how I can calculate these figures myself? This is incredibly helpful and exactly what I was looking for! For example, where in the ASR review does it say that the G5 can output 5-6V? I only saw a mention of 2.1V output. So, is there a formula to calculate the max voltage that can be delivered based on other numbers?

When audiophiles are talking about things are "hard to drive", they want to drive it to 120dB+ with headrooms left...
most people actually don't need that.

I figured as much! However, I do see many, many people talking about how harder to drive headphones, including the HE6SE, benefit from having a more powerful amp and how it purportedly "opens them up" and "increases bass dynamics" and other such phrases. Is it really all more or less placebo? Or in my case, will the headphones sound the same whether it's being powered by just the G5 or the THX 789 with the G5 acting as just an amp (assuming both cases are volume matched ofc)?

Conclusion: just use G5. no need for anything else.

I am a happy man then! As a recently graduated student, it is a bit tough trying to get my next upgrade while also keeping the budget in check. I was initially going to get an Arya Stealth, but the lower price + the A/B test from this YouTube video convinced me to go for the HE6SE instead

 

[oleg87]

Thank you for your reply. However, the sensitivity is 83.5dB at 50Ohm, although the ASR review measured it at 64Ohm. So assuming the worst case of sensitivity being 83.5dB at 64Ohm, how does that change things?
Also, apologies for this question but could you tell me or point to a source which can teach me how I can calculate these figures myself? This is incredibly helpful and exactly what I was looking for!

I figured as much! However, I do see many, many people talking about how harder to drive headphones, including the HE6SE, benefit from having a more powerful amp and how it purportedly "opens them up" and "increases bass dynamics" and other such phrases. Is it really all more or less placebo? Or in my case, will the headphones sound the same whether it's being powered by the G5 or the THX 789 with the G5 acting as just an amp?

Assuming the amp is not being driven to clip or audibly distort, there is no electronic basis for more power increasing "bass dynamics" or whatever, so sighted bias/volume mismatch is the explanation that remains.

More confusion comes from output impedance very audibly changing bass response with some headphones, but this is a separate issue from power (and most planars will not see frequency response changes due to output impedance).

 

[audiofun]

Thank you for your reply. However, the sensitivity is 83.5dB at 50Ohm, although the ASR review measured it at 64Ohm. So assuming the worst case of sensitivity being 83.5dB at 64Ohm and say I want to listen at around 105dB instead of 95dB, how does that change things?

your 83.5db is per mw, not V. The ASR review states [email protected], which is similar to 91dB@1V.
@solderdude 's measurement at here gives 91dB/V and 58Ohm, which is closer to the value I measured.

In any case, you shouldn't use the 83.5dB value.

 

[thecoolerplayer]

This is very insightful! So, all this talk about how one needs an amp with at least 2W of output power is essentially moot in the present day?
Why would Hifiman recommend having 2W of output per channel then? Is it simply a holdover from the time when the HE6SE were first released and powerful amps with the required voltage to drive them were far fewer; and now we have portable solutions like the Topping G5 which can adequately feed an HE6SE with the proper voltage?

 

[audiofun]

Why would Hifiman recommend having 2W of output per channel then? Is it simply a holdover from the time when the HE6SE were first released and powerful amps with the required voltage to drive them were far fewer; and now we have portable solutions like the Topping G5 which can adequately feed an HE6SE with the proper voltage?

because they want to drive it to more than 110dB. Remember when power doubles, it only increase dB value by 3. at 2W@58Ohm it's just 111dB and needs 11V voltage swing.
Headphone amps only become a lot more powerful in recent years. When HE6 was released very few could drive it to that level.
Normal headphone amps are built for normal headphones who have 100dB+/V sensitivity. HE6 is 10 dB lower. It needs both voltage swing and output power.
Sennheiser HD650, for example, only needs 2V to reach 110dB. Most headphone outputs such as the one on your laptop can get to 2V.

it's not a fault of headphone amps, but HE6, actually, as the tech to build planar magnetic phones were not very mature. Today's planar mag phones are a lot more sensitive.

 

[staticV3]

Firstly, will the Topping G5 be sufficient to get the most out of the HE6SE?

If it plays loud enough with no obvious distortion or clipping, then yes.

In that case, buying a more powerful headphone Amp would do nothing to the sound, except give you the ability to boost playback volume even more above your comfort threshold.

 

[thecoolerplayer]

If it plays loud enough with no obvious distortion or clipping, then yes.

Sounds good. I should be receiving the HE6SE in the next couple of days and will report back.

In that case, buying a more powerful headphone Amp would do nothing to the sound, except give you the ability to boost playback volume even more above your comfort threshold.

I have a bad feeling that once I EQ it, it might not have enough power from prior experience with the HE400i. The Sonata HD Pro was perfectly adequate for stock tuning, but once EQd, I had to get an amp. In any case, I will see for myself soon. But then again, I may not even want to EQ it so we will see

In any case, it's a relief to know that all the jargon and talk about how only a big amp will "properly" power this pair is not going to be true.

Thanks so much again everyone!

 

[solderdude]

HE6SE V2's sensitivity is 91dB/V. So even 4V output can give you 91 + 2 * 6 = 103dB.

103dB peak level means average SPL (depending on the recording) could be between 85 and 93dB SPL unless you play music with a DR of 3 or so in which case average levels will be around 100dB with no headroom left.
When EQ'in the bass to Harman levels you can substract another 5dB from the SPL.

The HE400SE will play about 3x as loud as the HE6SE at the same volume level.

And indeed the given numbers from HIFIMAN are simply wrong and not just slightly wrong either (they often are as well for other models too, both in impedance and sensitivity/efficiency.)

 

[audiofun]

When EQ'in the bass to Harman levels you can substract another 5dB from the SPL.

G5 uses analog volume control so you don't actually need to subtract.
Digital signal will be 5 db lower but the analog gain (12dB) will compensate for that.
The limitation is the voltage swing, not digital headroom loss.

in other words, the 5db eq boost is included in his 80-95dB listening level, not added to that level. Other wise he will be listening to 85-100dB on average.

 

[solderdude]

The 'loss' will still be there because the bass will be reaching clipping levels and loudness is determined by mid frequencies.

 

[audiofun]

I did some checking and you can tell the 68 ohm from the 50 ohm versions by the serial number and weight.

68 ohm 2204122xx 512 grams 9 digit S/N
50 ohm 220423xx 510 grams 8 digit S/N

They are definitely two different versions denoted by serial number under the pads. 9 digits for the 68 ohm and 8 digits for the 50 ohm. They're cosmetically identical, the driver cover when the pads off are identical too. I have an accurate postal scale, so the 68 ohm is 2 grams heavier. These are both new, so I'm guessing it's the drivers to cause the weight difference. I've got another one coming in this week to check out, have to remove the pads anyway to register the warranty. I tested with the same factory cable on each just for consistency. Going to check and see if any other their other models have this ohm rating on their drivers.

The ones Amirm measured have the ski style headband, and these are the V2 with the bar style one. I'll ask Monday, I have a contact at Hifiman and see if they know the difference in drivers, like if one is an earlier production model.

My serial number begin with 2506 and it's a 9 digit SN, with 56Ohm impedance. I believe the one @solderdude measured is the same.
So they are changing the driver again...

 

[solderdude]

HE6SE differs from the HE6SEv2.

The sensitivity and impedance numbers given by HIFIMAN aren't accurate.
Also there is bound to be some impedance differences between drivers in production runs of the membranes. That is related to the thickness of the traces that is applied to the membrane.

 

[audiofun]

HE6SE differs from the HE6SEv2.

I don't believe v1 and v2 use different drivers by design.
There are batch to batch variances but the same batch drivers may be used on either of the product versions.
See for instance, this measurements. the FR measurements of V1 and V2 are almost identical.
but In @oratory1990 and crin's measurements, V1 and V2 are different.
So a 2021 V1 may sound different to 2025 V2, but 2025 V1 should be identical to a 2025 V2 if they are the same batch.

I personally don't like that as end consumers will find it hard to EQ their headphones.

 

[shinbojan]

You do need a lot more power if you plan to use PEQ.
I like the stock sound of v2, I love it with PEQ.

 

[audiofun]

You do need a lot more power if you plan to use PEQ.
I like the stock sound of v2, I love it with PEQ.

Depends. If you boost the bass you probably need more power than no EQ as human ears are not sensitive to bass.
But the bass is already enough in HE6se unless you really want Harman-like tuning like Amir does.
I don't boost the base at all and found the sound to be very good.

The stock tuning is pretty good except the 2kHz dip and 4kHz peak. The 4kHz peak is not discernible in my pair so I guess latest batch improves that.
Even if it's there, EQing the the 4khz peak out doesn't require more power.
The 2khz dip, however, does need to be boosted imho. Hifiman's house sound is usually with such dip, but I think HE6se overdoes it.
Boosting it won't require more power as human ear are most sensitive in that region, and increasing the response will certainly increase the loudness by a lot.
So as a result you will eventually turn the volume down to keep the music at your comfortable level, and the required analog voltage swing will remain the same.

 

[thecoolerplayer]

I finally got my HE6SEv2 about a week ago, although I was able to spend some time with it only this week.

The Topping G5 is more than loud enough even at medium gain for my listening volume, and high gain is painful enough that I do not want to listen for more than 10-15 seconds.

However, when testing out various PEQ profiles (using exclusive hardware control through Hiby app via S23 Ultra), I can notice only a little bit of difference even with presets with +6dB bass boost. Is this because although there is enough volume, there is not enough "power" or something? I remember being able to detect much clearer and more obvious differences when I had the HE400i and I was playing with EQ with it.

I tried about 11:45 with high gain and around 2 with medium gain which provide roughly the same amount of volume, and I think I notice slightly more details, and slightly more "textured" bass, which I think are easier to spot when in high gain compared to medium gain (when trying to equalize the same volume level).

So, should I still get an amp like a THX 789? Or is this the limit, given that the Topping G5 is more than loud enough to drive it to ear splitting volumes? I have to say, I am sort of underwhelmed by this pair so far in terms of bass, where I was expecting tight, slamming bass but I am unable to get that without increasing the volume too much, even with heavy EQ. Thank you.

 

[audiofun]

Let's take a look step by step.

The Topping G5 is more than loud enough even at medium gain for my listening volume, and high gain is painful enough that I do not want to listen for more than 10-15 seconds.

G5 medium gain is 6Vpp (according to spec) / 2.828 = 2.1Vrms and that's loud enough for you.

However, when testing out various PEQ profiles (using exclusive hardware control through Hiby app via S23 Ultra), I can notice only a little bit of difference even with presets with +6dB bass boost.

With +6db Gain on all frequencies ( which doubles the voltage swing) it becomes 4.2V. Your +6db is bass boost so it definitely won't go beyond 4.2V

Is this because although there is enough volume, there is not enough "power" or something?

A clear NO to this question. Because as we talked about,

Topping G5 can output at least 5-6V without clipping to 50Ohm according to ASR review. (according to L7Audio it's beyond 6V).

G5 will not clip at all even at 6V. There's no possibility it cannot deliver enough power at 4.2V.

So, should I still get an amp like a THX 789?

No.

I have to say, I am sort of underwhelmed by this pair so far in terms of bass, where I was expecting tight, slamming bass but I am unable to get that without increasing the volume too much, even with heavy EQ. Thank you.

I am not able to answer that question. To me there's enough bass even if I don't boost it at all, and the bass is ultra clear. The drum sound has very clear impulse and starts/stops right at the point. My Sennheiser is not able to do that. and that's the happiest experience I have with this headphone.

I don't even need to use an external amplifier to achieve that. My MacBook Pro can already drive that to very loud levels, though not painful level, when I max the system volume. Your G5 is much powerful than my MacBook Pro. (MacBook Pro max at 1Vrms. With a fake 300Ohm resistor we can make it achieve 1.6Vrms without clipping)

 

[staticV3]

Is this because although there is enough volume, there is not enough "power" or something?

Definitely not.

I suspect user error honestly.

Did you apply an appropriate preamp in HiBy?

Without that, you'll just run into digital clipping so your boost won't do anything.

 

[shinbojan]

However, when testing out various PEQ profiles (using exclusive hardware control through Hiby app via S23 Ultra), I can notice only a little bit of difference even with presets with +6dB bass boost. Is this because although there is enough volume, there is not enough "power" or something? I remember being able to detect much clearer and more obvious differences when I had the HE400i and I was playing with EQ with it.

Check if your headphones have stuck magnets, that unfortunately happens often.
And I know that most won't agree, but a better amp will make the headphone sound better, it's not enough to make them loud enough.

 

[Mort]

And I know that most won't agree, but a better amp will make the headphone sound better, it's not enough to make them loud enough.

Incorrect