**Hifiman HE-400 Impressions and Discussion Thread** - Page 110

It lacks dynamics and body to my ears at low volume and high volume. One can only give opinions on here, my opinion is I do not like it one bit with the HE-400. I love it with the D7ks and some of my other cans.

Sigh.

What about the HD650?  Or is the O2 a poor match for those too? (not worried about sound sig at this stage, just ability to power)

 

I'm gonna be returning the 400s (if I can, or onselling them) if the sibilance doesn't f*** off when I hook them up to the O2.  At the moment, I'm *really* enjoying about 5% of the music I have and hating the other 95% (what I thought was a improvement was just the fact that I was listening to orchestral stuff rather than vocal-focussed stuff).

 

I really want to like these things, but my UM3Xs are just crapping all over them at the moment, s'yeah =/

The o2 does well with the 650 as well, people just prefer beefier sounding amps. It's a matter of amp sound, not power.

As far as I know the O2 is just a neutral amp. It doesn't mess with the sound signature. I've listened to the HE-400's off an extremely neutral amp(Xonar STX) and they sound good to me.

There's most likely aspects that affect an amps sound beyond fr and distortion, but outputting 600mw, 1w or 6w shouldn't make the difference.

Rev3 or rev2 HE400s? If it's the former then the sibilance is a defect; if it's the latter then yeah the sound signature is not for you.

It would be interesting hearing about those aspects, but they appear to be a well kept secret. If somebody is able to explain how two equally powerful amps with identical FR, same output impedance, and equal amounts of THD can have different levels of things like fullness of the sound that would be great.

It is a difference that can only be measured by your wallet! Lol.

 

I do think that equipment differences can matter to a point. My experience with car audio (a whole different issue from headphones) has taught me that there are key features that matter: Decks with time alignment, high volt outputs @ low impedance matter, properly shielded interconnects can matter (engine whine sux), and matching power requirements of speakers to amps. But nothing impacts the sound like well-chosen speakers, and to a lesser extent, attention to the installation. I paid more for amps and speakers than I had to years ago, but the key benefit was that the amps lasted for over a decade before finally calling it quits. Speakers are less finicky, but I've had dust caps thrown from subs because the glue had dried out and failed.

 

In the world of computer audio, I would take a VIA or Realtek chipset over sound blaster any day, but its hard to imagine that a dedicated amp and DAC could exert THAT much influence over the sound, unless the DAC/AMP was total crap. Their job is to replicate and amplify a sound anyway, not change it. If it is changing it drastically, something is horribly wrong.

 

Different deigns of amp and use of different components all contribute to a sonic signature.  ie the methods they achieve those stats can be different.  There are several designs of tubes for tube amps.  Each one has a different sound.  Transformers have their own sound depending on the design (toroidal vs EI).  Solid state opamps have their own character.  DACs have their own character (Burr-Brown anyone?).  

The Sennheisers HD650 are rated @ 102 dB/1Vrms. Innerfidelity says they reach 90 dB @ .13 mW. Just based on that, You would need approximately 133 mWs @ 300 Ohms to reach 120 dB, which should be more than enough for regular music, movies, and so on. The JDS Labs amp should put out 163 mWs @ 300 Ohms, based on the same math I am doing. At just 67 mWs, you should reach 117 in theory, which is really close also, but shows the jump in power needed to gain those last 3 dBs. JDS or the Schiit should provide ample power. A fiio E9 can probably drive them well also, as they should work well at higher impedances. Also the NuForce Icon.

 

A different website suggested sticking to Amps with rated power of 2Vrms or more for best results. This is probably true, but I would stick to lower output impedance. The Audioengine D1 probably does 13 mWs @ 200 Ohms (10 Ohm output resistance), which only reaches about 100 dB. There may not be enough "headroom" for high dynamic range material, like watching a DVD.

Matt and Fearless1 -

 

What did you connect to your O2s? What was the input device in other words? A line out from a computer? An iPod?

So I just got my he-400's, and I gotta say I'm not too impressed with the sound, I mean they sound good but they didn't blow me away like I thought they would.

Give them a little time. When I first got them, coming from hd650 and d2000, they never gave me a wow feeling, but I could tell they were super detailed. Give yourself a day or two to adjust to sound, their dark sound takes time to grow on you.