[billybob_jcv]

Hmm, well, I obviously can't hear with your ears, so all I can do is make guesses. From what you have said, it seems to me that the E10K is probably working as designed. I can't quite decide whether the core issue is that you simply do not like how the AKG sounds, or if the E10K is simply not making the level of improvement you expected. The E10K is really not a powerhouse amp. It provides a modest gain that works OK with a broad range of headphones. Using a handy spreadsheet I found on google, the K612, at 120 Ohms and 101 dB/V, works out to 91.8 dB/mW. That's really not very sensitive. However, it's not clear to me whether a different, more powerful amp, for example the Schiit Magni2, would make much difference in the areas of the sound that you have issue with. I suspect not. IMHO, an amp makes much less impact on headphones than most audiophiles will admit. Or, the K612 just might not be the right headphones for you. Just because they cost more doesn't mean you will like them more. I have heard very expensive headphones that I really disliked (*cough* Grado GS1000 *cough*) - but I know that many other people love them. *shrugs*

 

[TigerStripedCat]

Using various samples taken from bandcamp and other sources I got from the official free flac thread, I realized certified 24/96 music, stereo/binaural/headphone engineered audio tracks DO, in fact, sound much, much better than anything I've tried so far.
Also, the muddy lows response is caused by the E10 bass boost which actually bloats the low mid range instead of extending bass.
The combo still suffers from the conditions I've described, though, as far as other files are concerned. Even the abovementioned certified good files, although sounding much better, still "suffer" -if just at some degree- from those issues, but I'm going to assume that's just the color this particular setup gives off as a signature, and at such a low degree I can easily accept and appreciate it.
But regular music doesn't sound that good, even supposedly good flac files I download from specialized trackers. I only noticed a good improvement with hi-res stuff from bandcamp and other samples.
Also, I noticed the most improvement with symphonic music recordings and live recordings, acoustic especially. All kinds of audio in which soundstage accuracy and imaging are paramount, I'd say. Yes, this setup seems to affect mostly the soundstage and imaging rather than the accuracy and the emphasis of all ranges of sound (it does emphasize and improve accuracy in various ranges though).

So, maybe my issues stem from my supposedly good but actually ****ty flacs, or maybe the E10 doesn't power my cans sufficiently,  or maybe my cans are made for classic, symphonic, acoustic music.
I'll be able to report more when my Koss Porta Pro and my PA2V2 arrive home, so that I can compare different setups.

 

[billybob_jcv]

I suspect the commercial high quality HD tracks are made from high quality master recordings, and that's probably a much more significant difference than the difference between 16 bit/44.1K and 24 bit/96K - but that's a different debate that isn't appropriate for this forum.

 

[TigerStripedCat]

Well you're right, high quality master recording rather than shoddy master work is surely much more noticeable and appreciable than using 24/96 rather than 16/44.1, thanks for correcting me, I actually really meant to point out mostly the high quality recordings specifically engineered for headphone use and excellent mastering.

But this doesn't explain why my Interstellar OST sounds so terrible.
Also, how can I know the flac I'm downloading isn't just going to be a bloated, upscaled, glorified mp3, rather than a masterfully crafted recording?

 

[appsmarsterx]

 
But this doesn't explain why my Interstellar OST sounds so terrible.
Also, how can I know the flac I'm downloading isn't just going to be a bloated, upscaled, glorified mp3, rather than a masterfully crafted recording?

 
we can usually use spectral frequency display to analize a recording to tell if it's upscaled,  otherwise we can do very little to fix recording and mastering issues of a recording.

 

[TigerStripedCat]

   
we can usually use spectral frequency display to analize a recording to tell if it's upscaled,  otherwise we can do very little to fix recording and mastering issues of a recording.

I mean, what should I do to know beforehand that I'm downloading crap. Since it's obvious that not all recordings and masterings will be done in an irreproachable, accurate way, the issue boils down to know where to look for high quality works.
For instance, I went as far as subscribing to rutracker and downloading a lossless Interstellar pack to test this out, and yet it sounds horrible all the same as the generic thing you find on youtube.

Now my question is, where do I find the real thing? Is there actually a real thing? How do I know whether Zimmer simply let his work be butchered by distasteful recording and mastering or not, and there's actually a hi-res version? I mean, it would be foolish to think that for every track you own there's a high quality recording/mastering version out there, wouldn't it - but how to make sure there isn't?

 

[appsmarsterx]

 
Now my question is, where do I find the real thing? Is there actually a real thing? How do I know if Zimmer simply let his work be butchered by distasteful recording and mastering? I mean, it would be foolish to think that for every track you own there's a high quality recording/mastering version out there, wouldn't it

 
just get your music from a trusted source, that's the only thing you can do.
 
may be you can buy the original audio CD from here.
http://www.amazon.com/Interstellar-Original-Motion-Picture-Soundtrack/dp/B00OTLFGDW/

 

[billybob_jcv]

Unfortunately, in this instance, I think you do get what you pay for. Free anything carries with it more risk.

 

[TigerStripedCat]

Not really, just bought the real thing AND a special DTS version: it's still bad.

 

[mihai303]

After a little playing around I managed to reduce the sibilance. The process is described in other threads generally as EQ-ing the headphones. Basically you use Sinegen to determine the peak point of the frequency that bothers you (in my case 7300.0 Hz) and then use Equalizer APO to reduce the gain of that frequency. In my case I used the following filter in the Equalizer APO config.txt file : 
 
Filter 1: ON  PK       Fc    7300.0 Hz  Gain   -6.0 dB  Q  5,00 
 
The filter is applied system wide for the Fiio DAC sound device and can reduce the sibilance to a whatever extent you see fit. After playing around I think I understand the AKG 612 Pro better. The frequency that I EQ-ed is basically responsible for the sensibility of the headphones. I think in a studio environment they would provide the level of sharpness necessary to capture and reveal every vocal / instrument in detail .. but this is just a guess. But for normal playback I think they are a bit to critical and may actually reveal too much and make the listening too analytic and sometimes may even make the sound worse. So EQ-ing by reducing the sharpness in my point is necessary for normal playback and I think it improves the general sound.
 
If you own these headphones or any other good pair of AKG (http://eu.akg.com/quincy-eu.html) it would be a pity not to listen a Michael Jackson Audiophile Collection. I personally set them as a reference baseline in quality of how good the 612 Pro can sound and settle for nothing less.
 
For the Fiio E10k make sure that in the  SPDIF Interface properties in the Advanced Tab the 2 chanel, 24 bit, 96000 Hz (Studio Quality) - is selected. By default 2 chanel 16bits is used.