Signal processing? It's digitally sent bits of information - it's the same 010010101... in all devices
Maybe people complaints have more to do with badly compressed music or something. Anyway there's no logic in such theories.
BTW I also think that DAC in HTC One M8 is good enough so there's no reason in using external DAC. Unless there's not enough power - but in that case amp would be just as good or maybe better (depanding on the amp used). That's why I'm selling my FiiO E18 - it's just not worth it to carry it around....
Of course if someone install Viper4Android or some other audio "enhancements"/equalizer it will affect sound quality. But from what I've read most smartphones out-of-the-box (or after disabling boomsound and similar) has completely flat freq. response.
My point was that I don't know. You are probably completely correct.
Since equalization and effects such as V4A can be heard while using an external DAC, there must be some sort of upstream processing. (Maybe different devices have different ways of compressing files that have a superfluous bitrate down to something that can be sent over USB? I don't know.) As such, perhaps different smartphones cook in alterations to the digital signal prior to sending it out over USB that we don't know about. That was my logic, anyway.
I mean, I know I'm splitting hairs, I just really enjoy doing so
I have the One M8 and I agree - why would you bother to add an external DAC? And it gets plenty loud enough for me too, so no amp needed either.
That's right, I am a naked head-fier. Oh the shame.
I've not been in the hifi audio world for very long, so I'm not really familiar with the crucifixion that you were expecting for being "naked". It certainly won't come from me.
Though if you'll indulge me:
I have some experience in another hobby of mine, amateur astronomy. In the world of telescopes and eyepieces, you can purchase equipment worth 10x (maybe even 100x) more than what you used to have, and be denied distinguishably better views on a given night. But on an especially clear night, when the planets align (figuratively), you'll be able to tease out that extra band on Jupiter, or make out that wisp of the Veil Nebula that you've never seen before. At least for me, that's exciting.
From my very limited experience in appreciating quality audio, I treat it the same way. To me, ABX testing illustrates almost nothing but the most blunt and obvious of differences. What if you were having a bad day? Or a series of bad days? If it's overcast (or light polluted), it doesn't matter how big your telescope is or how expensive your eyepieces are (to an extent). For me, it's about investing in those unpredictable moments of clarity. There will be fantastic moments when the air is especially dry, your body is especially relaxed, and your mind is especially clear (I don't know, I'm just making things up, but you get the idea). One day you're sitting there enjoying some music with your new audio equipment, and suddenly a musical passage that you know so well pops out at you, or the texture of someone's voice seems particularly detailed. And the next time you put the same music on, you'll remember what you heard, and hear it again.
I don't have very sensitive ears. My Fiio recently arrived, and I honestly can't tell the difference between the M8 headphone out and the external DAC, right away. Heck, often times I can't even tell the difference between a 320kbps MP3 and a FLAC. But I'm going let months and hundreds of hours of listening deepen my appreciation. And when those moments of clarity happen, I just might owe them to the new equipment. Although I'll probably never know. It'll probably a combination of things, and I'll never be able to delineate the effects of every individual factor. And that's fine by me. Music certainly sounds better now than when I was using my Galaxy S2 with $10 earbuds.
So perhaps it's me who should be crucified for spending money (that I arguably shouldn't spend) on equipment that I seemingly can't, and might never, appreciate. But I have a differing point of view on this matter. I'll doggedly haul around that E18 in my pocket every day waiting for those moments of clarity. And when I hear them, I'll be happy. That's it.
I certainly am not implying that you haven't spent due time auditioning the M8 with and without the DAC, or that you don't know how to properly appreciate audio equipment. I'm simply offering my defense for using the M8 with an external DAC. Perhaps someone else making similar decisions can benefit from this discussion (and take what I say with a grain of salt, from the saltshaker of inexperience).
