Amplification and The HE6se v2

[AryaStealth]

Sorry for a dumb question, is it possible that my HE6SE V2 unit sounds dull with Oratory PEQ settings with -5.5db preamp because of an inadequte amplification?
I'm using an unbalanced output of Sabaj A20d 2023 (HPA Power 2W*2 16Ω, 1W*2 32Ω - not sure if these specs are for unbalanced or balanced output, or for both) in High gain (+8db) and Sabaj volume level set at 80 (Loud enough for me). This DAC+AMP has TI TPA6120A2 as an amplifier (Output power 1.5W, Load (min) 8Ω, PSRR 75 dB).
I have to say that my unit HE6SE V2 has an audible channel imbalance (vocals that supposed to be at the center are always moved to the right sight), perhaps this (bad quality drivers?) is the cause of a rather poor and narrow sound and not an amplifer?

 

[IAtaman]

Sorry for a dumb question, is it possible that my HE6SE V2 unit sounds dull with Oratory PEQ settings with -5.5db preamp because of an inadequte amplification?
I'm using an unbalanced output of Sabaj A20d 2023 (HPA Power 2W*2 16Ω, 1W*2 32Ω - not sure if these specs are for unbalanced or balanced output, or for both) in High gain (+8db) and Sabaj volume level set at 80 (Loud enough for me). This DAC+AMP has TI TPA6120A2 as an amplifier (Output power 1.5W, Load (min) 8Ω, PSRR 75 dB).
I have to say that my unit HE6SE V2 has an audible channel imbalance (vocals that supposed to be at the center are always moved to the right sight), perhaps this (bad quality drivers?) is the cause of a rather poor and narrow sound and not an amplifer?

It is not a dumb question, it think those are fair questions to ask.

A20D might indeed be running our of power to drive HEse V2. Amir measured it 1W into 33ohms so It can most likely do less than 1W into 50ohms. With -5.5dB pre-amp it might indeed be running out of power at times. That will most likely effect to lower registers however so why don't you remove the -5.5db preamp and see if the bass sounds better.

For the channel imbalance, it might be a channel issue with the amp. When you try a different headphone, do you get the same "leaning to right" effect? If no, then mostly likely a headphone problem. If yes, then it might be the amp, or it might be your hearing as well. Maybe you can get someone else to try the headphones too?

 

[AryaStealth]

I followed your advice and disabled PEQ settings and negative preamp, and I feel the overall stock sound seems much better without EQ, so I guess it either means that there is not enough amplification power (somehow I thought I would hear lack of power with a clipping sound from the Sabaj's integrated amp when using EQ, but I don't hear any clipping with EQ when listening to bass heavy music) or my unit has a different frequency response than those measured by Oratory which means that I can't use his settings, so I guess it is also possible since there is definitely a channel imbalance present like I described above. I have a pair of calibrated Audeze MM-100 from Sonarworks and when I listened to the same tracks on them the vocals are right in the center, on my HE1000 Stealth I also didn't notice the same "leaning to right" effect as it happens on HE6SE v2.
What amplifier would you recommend for HE6se v2? (not expensive, and if possible available on EU/UK amazon, so I could return it if doesn't improve the sound after EQ)
DROP + THX AAA 789 would have enough power only when connected to a DAC in balanced mode?

Should FiiO K7 in balanced mode (2000/560 mW at 32/300 Ω respectively) be enough for HE6se V2?

 

[Doodski]

or my unit has a different frequency response than those measured by Oratory which means that I can't use his settings

Yuck! Why use somebody else's settings when their ears work differently. Invest 5 minutes and tune that PEQ to your desires.

 

[AryaStealth]

Yuck! Why use somebody else's settings when their ears work differently. Invest 5 minutes and tune that PEQ to your desires.

I believe EQing blindly by ear is a two way sword, you can improve the sound of one track and at the same time diminish another, that's why from my experience Oratory's settings are the best all around, at least as far as Hifiman headphones are concerned.

 

[Doodski]

I believe EQing blindly by ear is a two way sword, you can improve the sound of one track and at the same time diminish another, that's why from my experience Oratory's settings are the best all around. At least as far as Hifiman headphones are concerned.

Baaaa! LoL. Use your own gifted ears and stop being all that. Nobody can set the EQ/PEQ for you because their ears are different and personal taste is involved. Millions of people EQ/PEQ and are very happy.

 

[IAtaman]

What amplifier would you recommend for HE6se v2? (not expensive, and if possible available on EU/UK amazon, so I could return it if doesn't improve the sound after EQ)
DROP + THX AAA 789 would have enough power only when connected to a DAC in balanced mode?

Should FiiO K7 in balanced mode (2000/560 mW at 32/300 Ω respectively) be enough for HE6se V2?

Well, with nominal 83 dB/mW efficiency, and 50 ohm impedance, you'd need an amp that can deliver ca 9V and 1.6W into 50ohm to make sure it is driven without any issues. So that is your basic power requirements. Your choice might depend on other features - maybe you need a DAC+AMP combo with BT, maybe you need line-out or I2S. I can only comment based purely on power needs perspective, rest is up to you.

AAA789 specs says 6W at 32ohm 1% THD, but Amir measured 1.3W into 32ohm before clipping so I would be a bit hesitant to go with that if I were you.
Fiio K7 claims 2W into 32Ohms. That translates to 8V, and I was not able to find info on its output voltage. It might be able to scale up to 9V you need, but I am not sure.

Based purely on power, cheapest amp I know that can do what you need is L30 II. It is readily available in the UK/EU.

Headphones Power Calculator

Calculate the power needed to drive your headphone based on sensitivity (db/mw or db/V), impedance (ohms) and loudness (dbSPL)

www.headphonesty.com

 

[IAtaman]

I followed your advice and disabled PEQ settings and negative preamp, and I feel the overall stock sound seems much better without EQ, so I guess it either means that there is not enough amplification power (somehow I thought I would hear lack of power with a clipping sound from the Sabaj's integrated amp when using EQ, but I don't hear any clipping with EQ when listening to bass heavy music) or my unit has a different frequency response than those measured by Oratory which means that I can't use his settings, so I guess it is also possible since there is definitely a channel imbalance present like I described above. I have a pair of calibrated Audeze MM-100 from Sonarworks and when I listened to the same tracks on them the vocals are right in the center, on my HE1000 Stealth I also didn't notice the same "leaning to right" effect as it happens on HE6SE v2.

Well, based on Oratory's measurements, I'd personally start with 3 filters, add a bass shelf at around 70Hz, fill in the hole at around 2KHz and maybe bring down 4KHz a bit. Your pre-amp will be more or less the negative of bass shelf with that setup. I'd go with 5dB probably, but your taste might be different, so amount of bass shelf you prefer might be different. So, if you add a 3dB shelf for example, you can get away with -3dB preamp.

He6 family can do amazing bass, not adding a bass shelf would be leaving performance on the table in my opinion, but that is my view, not a fact.

 

[Roland68]

I followed your advice and disabled PEQ settings and negative preamp, and I feel the overall stock sound seems much better without EQ, so I guess it either means that there is not enough amplification power (somehow I thought I would hear lack of power with a clipping sound from the Sabaj's integrated amp when using EQ, but I don't hear any clipping with EQ when listening to bass heavy music) or my unit has a different frequency response than those measured by Oratory which means that I can't use his settings, so I guess it is also possible since there is definitely a channel imbalance present like I described above. I have a pair of calibrated Audeze MM-100 from Sonarworks and when I listened to the same tracks on them the vocals are right in the center, on my HE1000 Stealth I also didn't notice the same "leaning to right" effect as it happens on HE6SE v2.
What amplifier would you recommend for HE6se v2? (not expensive, and if possible available on EU/UK amazon, so I could return it if doesn't improve the sound after EQ)
DROP + THX AAA 789 would have enough power only when connected to a DAC in balanced mode?

Should FiiO K7 in balanced mode (2000/560 mW at 32/300 Ω respectively) be enough for HE6se V2?

Two devices that are inexpensive and have over 3 watts of measured power are Topping L30 II and L50.
If you operate your headphones via a balanced connection, then you would have a measured output of 7 watts with the Topping L70. I can also recommend this HPA without reservation in terms of sound.
The L70 is sometimes available as a customer return on Amazon for €300 or less.

And one rule has always applied to amplifiers: they can have too little power, but never too much. If the power is not needed, simply reduce the gain.

 

[AryaStealth]

I was asking about Fiio K7 because I have it as a backup for Sabaj A20d. I never listen louder than 77db (82db peak), usually I prefer about 70-75db when EQed to Harman, so I guess 8Volts from K7 should be more than enough for that volume, unless my he6se v2 unit has higher impedance than officially published 50ohm. I saw on reddit someone wrote that K7 has 2W power at 68ohm, but I don't understand how this figure was found on this measurment. Fiio official specs for K7 via 6.35mm output

Peak output voltage

≥18.9Vpp

and for the balanced output:

Peak output voltage

≥37.7Vpp

Is it possible to convert these Vpp figures into RMS Volts and current RMS mA?
I listened yesterday to HE6se v2 connected to Fiio K7 in balanced mode, and the sound was a bit better with EQ than on Sabaj A20d, but it still can be described as a big disapointment for me (especially with classical music). Perhaps I have indeed received a defective unit with very high impedance (the magnets don't appear to be stuck if we can definitely establish it by shadows), I bought it as a return from Amazon and judging by the quantiny of torn out labels on the he6se box, it was returned at least 2 times already.

 

[IAtaman]

If you are suspicious that the product has a defect, just return it. While you are trying to figure out is it the EQ, is it the amp, you might ran out of time.

From the measurements you shared, looks like K7 can drive them. They seem to have the voltage and the current to deliver the neccessary power to H6se V2.

You can convert peak V to RMS with some basic assumptions, but in order to know whether an amp can drive a headphone properly or not, you need to know both Voltage and Current or Power at given impedance or voltage. This is to mean that It might be an amp can produce 18V for example, but only at 600ohm load, and can only deliver 30mA. In that case you will be limited by the current.

It might indeed be that you listen to 77dB average, but it is quite likely the peaks will be well above that, depending also on the music. Check out this video from Amir for more insights.

When looking at how much power a headphone needs, I always check it for 115dB. As Roland68 said, when it comes to amps its always good to err on the side of extra power.

 

[IXOYE]

I believe EQing blindly by ear is a two way sword, you can improve the sound of one track and at the same time diminish another, that's why from my experience Oratory's settings are the best all around, at least as far as Hifiman headphones are concerned.

I always use Oratory's settings as base, and almost all profiles have a box where he recommend which frequencies you can change to fine-tune the sound to your liking, it has worked very well for me, I usually adjust for less bass and a bit warmer sound than Harman.

 

[AryaStealth]

Sorry for a dumb question again, in case he6se v2 have real impedance 64ohm and not 50ohm, as it was the case with he6se v1, will Topping L30 ii be enough to drive them without distortion?
I can't find 64ohm load on this measurments:

 

[staticV3]

Sorry for a dumb question again, in case he6se v2 have real impedance 64ohm and not 50ohm, as it was the case with he6se v1, will Topping L30 ii be enough to drive them without distortion?

Assuming identical impedance and sensitivity as the HE6se V1, the L30II can drive the HE6se V2 to about 114dB SPL Peak.

For reference, my usual listening volume is about 10% of what the L30II+HE6se is capable of.

 

[AryaStealth]

So if I use -5.6db preamp for EQ that would mean 108db SPL peak without distortion/compression of low frequencies (enough voltage swing)?

 

[solderdude]

That would mean 113dB SPL at low frequencies. You would just need to crank the volume up 5.6dB if you are only playing a single low frequency.
Acc. to Fletcher Munson 20Hz at 114dB would be perceived as 80Phon, 40Hz at 105Phon
but acc. to 2003 Equal loudness contours both 20 and 40Hz would be perceived as 110Phon

Also note that in music the maximum voltage swing would consist of all present amplitudes in the spectrum at that specific moment in time (sample) that reach 0dBFS meaning that SPL peak will be reached and while most energy will be in the bass the bass notes themselves might not reach 113dB SPL but will be lower.
At these SPL one is likely to only play music this loud that has a high DR rating. Low DR (highly compressed recordings) are not pleasant to listen to at high SPL.

 

[IAtaman]

Sorry for a dumb question again, in case he6se v2 have real impedance 64ohm and not 50ohm, as it was the case with he6se v1, will Topping L30 ii be enough to drive them without distortion?
I can't find 64ohm load on this measurments:

It can produce 3.4W per channel at 32 ohms. And it can deliver ca 0.6W into 300ohms - so it has the voltage gain as well. It will most likely be fine delivering 1.6W into 64ohms.

 

[ObjectiveSubjectivist]

I used them with Topping L70 without any problem.
Preamp was about -5~-7db to boost the bass and I had no issues even with high dynamic range classical music.

 

[Roland68]

Sorry for a dumb question again, in case he6se v2 have real impedance 64ohm and not 50ohm, as it was the case with he6se v1, will Topping L30 ii be enough to drive them without distortion?
I can't find 64ohm load on this measurments:

I just connected my L50 (same power and power amp as L30 II) and it is more than sufficient for the HE6se V2, with and without EQ. On high gain I can't turn the volume control above 11:00; personally, the L50 at the medium gain level is completely sufficient for me.

The same with the L70. Low gain is enough for me, at high gain it is of course even louder and has a lot of headroom.

Both only connected to 2.0 volt RCA.
On an XLR with 4.0 volts, both are of course significantly louder, due to the double input voltage.

 

[Blorg]

Should FiiO K7 in balanced mode (2000/560 mW at 32/300 Ω respectively) be enough for HE6se V2?

I used it with the Fiio K7 and it was just about enough, with Oratory1990's EQ (-5.5dB preamp). The K7 does just over 2W into 68Ω, measured. It actually has higher power than its spec sheet. Hifiman recommend 2W for this and I think that's about right. L30II should be good too, it's better on the spec sheet but in terms of measured power into 68Ω, if anything the K7 looks slightly better. The L30II has more power into 16Ω but that's not relevant to the HE6SEV2. K7 does better at 32Ω and 68Ω. They're close though, I think they would be about the same, but I have actually used it with the K7 and not the L30II. I use them mostly on a Topping A90 which is more than enough power.

Fiio K7:

Topping L30II: