Hifiman HE400i Review 2020 Revision (Headphone)

[peniku8]

This happened half a year ago.
Since then he learned driving the HE6SE directly from a phone wasn't such a good idea

lol no, HE6se only being used on my EX5, sometimes on a Fireface UC (the Fireface being a bit on the weak side for these)

 

[Axchisler]

Lol, I know, still some good info in there (I just got a great deal on some like new HE400i 2020's). I was interested how things turned out with the HE6SE however. The EX5 has plenty of power to drive them?

 

[staticV3]

The EX5 has plenty of power to drive them?

The EX5 can deliver 6.4Vrms @65Ω.
The HE6SE has a sensitivity of 91.27dB SPL/Vrms @425Hz, so the EX5 can drive it to:
91.27+20*log10(6.4)=107.4dB SPL.
EQing to Harman will reduce volume by about 7dB.

Edit: in case "them" in your question was referring to the 400i 2020, here are the numbers:

At 46Ω the EX5 can do 6.2Vrms. HE400i 2020 is 104.5dB SPL/Vrms @425Hz.
104.5+20*log10(6.2)=120.3dB -> very very loud.

 

[Axchisler]

I was referring to the HE6SE. I was under the impression that the impedance is 50ohms and the sensitivity is 83.5dB respectively. Did I miss something?

 

[staticV3]

Yes. HiFiMan's official specs are not reliable.
The HE6SE has been measured by Amir and SoundStageNetwork and both found an impedance of 65Ω flat and noticeably lower efficiency/sensitivity.
79.3/80.3dB SPL/mW or 91.3/92.3dB SPL/Vrms

 

[peniku8]

I can take an impedance measurement when I got my replacement pair if anyone is interested.
I can't take accurate sensitivity measurements though