[MatsGyver]

As explained above, the volume control on the Xonar Essence STX is digital, and the absolute noise level is not affected by the volume or the gain setting. In other words, it always outputs the maximum amount of noise. This can be an issue with sensitive low impedance headphones (which are often not recommended anyway for other reasons, like output impedance). The noise can be reduced by using 48, 96, or 192 kHz sample rate, and making sure that software volume control with 16 bit resolution is avoided.

Interesting.

So high impedance headphones dont have the same noise floor as low impedance headphones? So if i buy a 300-600 ohm headphone the noisfloor will not be as present as on my 50hm headphones?

On classical music the noise is very audible. Will this change if I buy a headphone with higher impedance?

 

[MatsGyver]

The hiss noise is less audible in between songs, so most of the noise probably comes from the recording, but will higher impedance headphones change this hiss too?

 

[stv014]

You cannot reduce noise that is already in the recording, other than by trying to apply a digital noise reduction algorithm, which is a lossy process itself, and cannot recover the information under the noise floor. The only kind of noise that is reduced by less sensitive headphones is noise on the amplifier output that does not depend on the volume setting (i.e. it is added after the volume control).

 

[stv014]

So high impedance headphones dont have the same noise floor as low impedance headphones? So if i buy a 300-600 ohm headphone the noisfloor will not be as present as on my 50hm headphones?

 
If your 50 Ω headphones are the LCD-2, then those are already not very sensitive because of the low efficiency.

 

[UltMusicSnob]

The hiss noise is less audible in between songs, so most of the noise probably comes from the recording, but will higher impedance headphones change this hiss too?

If the program material you're listening to was originally Dolby-analog, then it was created with a pre-emphasis in higher frequencies. If that was ripped straight and played back without the compensating playback de-emphasis, then the hiss will be noticeable and troubling.

 

[xnor]

I want to add that headphones themselves don't have a noise floor. They just play the noise floor of the source at a given SPL depending on their sensitivity. You can pretty much ignore impedance. Look at the sensitivity with 1V of input (not 1 mW!).
 
I have a couple of headphones listed in the table here. (column S@1V [dB SPL])
 
The Shure SE535 with 133 dB SPL would be a horrible match for a "noisy" source for example.

 

[proton007]

My most enjoyable upgrades thus far have been IEMs/Headphones.
 
Nothing changes the sound as dramatically, and IMO its the best way to relish all the different flavors of the sounds of music.
 
Just ensure the setup is not coloring the sound itself, its the most methodological way of going around this.
 
Thats if you're an engineer. If you're an artist, you may go with the flow, and change the DAC first, followed by the Amp, and then the headphones, and then change some more until you find audio-nirvana, which will change again when you wake up the next day. 

 

[stv014]

Thats if you're an engineer. If you're an artist, you may go with the flow, and change the DAC first, followed by the Amp, and then the headphones, and then change some more until you find audio-nirvana, which will change again when you wake up the next day. 

 
Do not forget about cables, and "audiophile" music player software that reduces jitter.

 

[krismusic]

The OP sounds like a very level headed chap. Lets not even mention cables!

 

[MatsGyver]

I want to add that headphones themselves don't have a noise floor. They just play the noise floor of the source at a given SPL depending on their sensitivity. You can pretty much ignore impedance. Look at the sensitivity with 1V of input (not 1 mW!).

I have a couple of headphones listed in the table here. (column S@1V [dB SPL])

The Shure SE535 with 133 dB SPL would be a horrible match for a "noisy" source for example.

I see. Its the combined sensitivity and impedance that makes them less affected by noisy sources. To a point at least.

 

[proton007]

The OP sounds like a very level headed chap. Lets not even mention cables!

 
I forgot to add specialized crystals that improve the ambient signal quality. And what audiophile would ignore specialized power supplies that need to weigh atleast a stone?

 

[SunshineReggae]

  Since I can't very much get my head around audiophile terminology because I don't have (yet) any terms of comparison, I'll try with an analogy:

Let's say I have a 50 inches display, which if I'm close enough to will fill my entire field of vision just like a pair of headphones covers the entirety of my ears.
Now, going from a pair of cheap earbuds to my current equipment for me was something comparable to going from VGA to FullHD.

What I heard was an "increase of resolution" and "decrease of artifacts". I mean, no more "kkkhhh" background noise, I could hear a triangle going "DING" instead of just hearing a "NNNNG" sound, I didn't have to raise the volume to uncomfortable levels to be able to hear every part of a song, which however introduced distortions in the edges of the audible spectrum (I don't what they are called, the classic noise you hear when you raise to the max the volume of a cheap stereo).

I'm not disappointed with my current headphones, but I feel like there could be something more. Let's say I don't quite feel like they are retina resolution, but since I can't compare them to something superior, I can't really be sure. Maybe that's just the limit of my hearing.

Also there is a point from which increasing the resolution does nothing, since the eyes wouldn't be able to see the difference. Nevermind the fact that at that point most of the source material would be mastered at a lower resolution, so you wouldn't gain anything even if you were theoretically able to see the difference.

The same as with a retina screen: if most apps aren't optimized for it, they'd just look like crap.
Maybe this could be comparable to when people say some headphones are "revealing" and "unforgiving"?

Anyway, I'm guessing something similar happens for audio: there is a limit beyond which the human ears (and everything behind them) aren't simply able to tell the difference. It's a simple matter of design of the human body, nothing really we can do about it for now.

All things said, here's a very idiotic question: cheap earbuds are VGA, now I'm on FullHD. Would be switching to something like a pair of HD 800 comparable to switching to a retina display?
Yeah yeah I know I know, forgive me.
 
 
I don't really feel like considering orthodynamics because they weigh a lot and I haven't read many happy opinions regarding their comfort, which is paramount to me given for how long I tend to keep headphones on my head and completely forget about them.
 
 
About the Xonar Essence STX, what bothers me about it is the fact that I wear my headphones all the time when I'm at my PC, for hours straight, and when nothing is playing I hear a constant hiss that with time is starting to annoy me. The noise floor in my studio/computer/listening room is very low (I measured it just a few days ago: 14dBA/18dB from my chair in front of the desk) and when I tried to move to other noisier rooms I wasn't able to hear it, so it's not really high, but it still annoys me.
It's probably caused by some noise source inside the computer, so I guessed that if I were to buy an external unit I wouldn't hear it anymore.

 
There may be a reason for you to "sidegrade" if you can't get rid of the hiss by messing around with your hardware and stuff. A fiio e9 with e7 dac would probably be a very good alternative, giving similiar audio quality. In my experience, the upgrade from a 595 to for instance a 650 is definitely worth it. The difference to me (I went from 598 to 650) is dramatic and in hindsight definitely worth a few hundred bucks for years of listening.
 
As for "upgrading" the amp... No. Don't start fooling around with tube amps and wacky designs. It's 2013 now. Hi fi technology just isn't a big deal anymore. Think about it: today we have amps/dacs available in five buck mp3 players as small as a coin that do an okay job. You can go on the internet and read lots of articles debunking many of the myths known to this hobby. It's time to start leaving the 20th century behind. It's very hard to "beat" anything that's on the level of an e9, 02 or STX because they feature modern technology with great engineering. And there isn't much reason you would want to because you'd already be way into the realm of diminishing returns. Whatever you feel ends up lacking, solve it with DSP. Don't waste your money on nonsense and don't be blinded by hopelessly outdated views on audiofilia.

 

[stv014]

  There may be a reason for you to "sidegrade" if you can't get rid of the hiss by messing around with your hardware and stuff. A fiio e9 with e7 dac would probably be a very good alternative, giving similiar audio quality. In my experience, the upgrade from a 595 to for instance a 650 is definitely worth it. The difference to me (I went from 598 to 650) is dramatic and in hindsight definitely worth a few hundred bucks for years of listening.

 
Due to its lower sensitivity, the HD650 might actually fix the hiss as well.