HifiMAN HE-6 Planar Magnetic Headphone - Page 486

 

Finally got the link to work. Very intriguing amp HC! Trying to imagine what a matched quad of NOS Mullards might sound like which would add another four to five hundred bucks to the purchase. For those of us that prefer valves to SS, this bears further investigation.

Edited by Dr. Roberts - 11/12/12 at 7:41am

That box is enticing!

 

I tend to be skeptical of "number crunching" rather than "result measuring" when it comes to anything HiFiMan, simply because Fang bakes the numbers...period.  Not that he's the only one in this business doing so (D&M....), but simply put, the numbers for most HiFiMan headphones aren't worth the paper they're written on

 

I mean the weight of the HE-500 is severely below what everyone with a simple digital scale has managed to come up with....imagine the performance numbers?  Tyll measured the impedance at 53, but there's supposedly variance between units.  But at least that number seems to be fixed. But the sensitivity numbers.....I don't know where Fang gets them from.  Sennheiser instruction manuals or something I'd guess, because they don't seem to be related to anything that says HiFiman

 

HE-400 should be almost Denon sensitive by the numbers.  They're not even close.  HE-6, by the numbers, I should be blasting my ears out and possibly rupturing the drivers at 0db into my power amp at 50% volume.  Instead, 50% is "normal listening volume" when a recording has plenty of near-zero dB peaks.  The one take-away we get is: The sensitivity numbers are best ignored!

 

Now in terms of current, and 5w (I didn't go back and read the previous page but at 5w I'm guessing we're talking about Mjolnir) as has been said before I think the limitation is not the 5w, but the fact that 5w refers likely to peaks, presuming that the headphone is not pulling continuous current near that level and still having reserves left for peak swings.   However, I have not yet tried HE-6 on MJ so my actual impressions versus a power amp are not yet formed. My expectation is that it will sound excellent.  We'll see!

Edited by IEMCrazy - 11/12/12 at 9:34am

um, 83 dB sensitivity re 1 mW

 

10 W is 10^4 mW = +40 dB power

 

83 + 40 = 123 dB

Right!!!!! Anyone can do the math, but if you really want granularity, here you go...

83db @ 1mw
86db @ 2mw
89db @ 4mw
92db @ 8mw
95db @ 16mw
98db @ 32mw
101db @ 64mw
104db @ 128mw
107db @ 256mw
110db @ 512mw
113db @ 1.024w
116db @ 2.048w
119db @ 4.097w
122db @ 8.2w
125db @ 16.4w
128db @ 32.8w

Etc etc etc

So if you want unclipped 120 dB peaks, you better have at least 8w into the HE-6's impedance on hand...
Edited by Skylab - 11/12/12 at 12:05pm

I am totally skeptical, but it was interesting that he just threw that blanket statement out there. (This was in the BHSE thread) and so I just wanted to know

if the locals here had something to say to the contrary.

 

And I have no idea what amp El Doug was referencing. 

 

Oh I don't dispute your math on the matter, that's a simple calculation.  But you're basing the math on the 83dB sensitivity.  That's the number I'm skeptical of.   83dB for HE-6, 92dB for HE-400.  AFAIK those numbers are as fictional as purple unicorns that line dance.  I think Fang considerably overstates the sensitivity on all his headphones and in reality the sensitivity rating for HE-6 should be considerably lower than that, which would change the math and show a very different power requirement for getting to 123dB

 

Similar with HE-400, there's simply no way they're 92dB @ 1mW.  No way, no how, regardless of what the spec sheet says.  They're sensitive compared to HE-6 and HE-5, but they're not that sensitive.

I believe as IEM does that they are extremely over estimated at 82db, more like 70. That's why the power. No, it's not as loud as the formulas indicate. As for the variance of impedance, Mine read 41.1 and 41.3 ohms at the xlr pins.
Edited by Happy Camper - 11/12/12 at 4:06pm

I used to believe that too, but Kevin Gilmore said in this thread that he measure them at about the claimed sensitivity, and that's good enough for me. Still, for music with a lot of dynamic range, I think even 5 W is questionable.

Then nuf said about it's efficiency. I agree with the power. 8-10 watts or less with high current rating.

tyll's calibrated measurements here

http://www.innerfidelity.com/images/HiFiMANHE6.pdf

 

20mw for 90db.

 

Differences in various measurements depend on the

dummy head, and a bunch of other factors. Even so, its

about 1 db max.

Hmmm...so if 90dB requires 20mw, then the power requirements table would look more like this:

90db @ 20mw
93db @ 40mw
96db @ 80mw
99db @ 160mw
102db @ 320mw
105db @ 640mw
108db @ 1.3w
111db @ 2.6w
114db @ 5.1w
117db @ 10.2w
120db @ 20.4w

Etc etc

So if you want 120db you need 20 watts, not 8! That is a big difference, and would mean that the HiFiMan spec is indeed optimistic.

sorry but for one more db, the power requirement is the double or not?

for example:

90 db@ 20mw

91 db@ 40mw

92 db@ 80mw

...

...

99 db@ 9,6 watt

No it's every 3db.

So, in theory, my balanced beta is good because at 50 ohm the power is around 7-8 watts