Originally Posted by emcdade
I think that what you're missing, deliberately or otherwise, is that even the DAC's whose goal is to "do no harm/alteration" to the signal such as a Benchmark still has a sonic fingerprint in comparison to other DACs.
First of all, nobody knows what the "absolute sound" that you claim to strive for is. A useless goal IMO but to each their own. Many people associate Benchmark's DAC sound as slightly thin sounding in comparison to others. Is that the absolute sound then?
Secondly, even Benchmark must make the call if they want to use linear vs. minimum phase filters, do they want to upsample all signals to a rate before filtering, what sample rate that is, what type of analog output stage to use, etc. etc. These all impact the sound, as Benchmark freely admits.
Lastly, I do not buy components to "color" my sound a certain way. I did buy components that produced the synergy that was pleasing to my ear in my own room. And after testing many DACs I can say with certainty that they do sound quite different. I would say that most are fairly similar in tonality with some slight differences at the frequency extremes, but the most striking differences are usually in the creation of soundstage presentation (forward vs. back) and the overall space and air that they produce.
I read these things, and I can't help but think to myself, "self, what produces the creation of soundstage -- how does one perceive a thing as "having more air" or "being more forward" -- what must be mangled in an audio signal to ruin such a thing?" As I answer these questions, I think, "and...what about a DAC could mess that up?" And, between those two things, I start to think you're either full of it, or bound to the same rules of expectation bias as the rest of us.
I mean, if I were in a room, playing a saxophone in front of you, how could I make it sound like I, "moved forward". I mean, I could...actually, physically, walk
forward. So, let's say I do -- what changes:
Level -- I'm closer, my sax will (probably) sound louder. The frequencies played by my saxophone (in relation to other frequencies present in the room) (probably) goes up (probably because who knows, I could end up in a location where all my reflections are absorbed and you don't hear them and the overall level that your ears integrate into signal over time goes down).
Timing -- sound gets there a little bit sooner. What effects timing? Phase? Delay? It'd have to be group-delay or some frequency-range specific phase anomaly just impacting my sax frequencies to impact nothing else, though....
Reflections -- my sax isn't hitting the same places in the room so combined response may be different (but, speakers don't walk, so...this is preset).
Now, what about a DAC (or amp, or AVR, or, etc...) could impact those things (for only my saxophone in the signal and nothing else)? And, if the WHOLE STAGE moved forward...well...that's a bit easier to analyze because the WHOLE SIGNAL was probably modified equally (and, in this case, I'd give the prize to level since it's a common issue that people don't properly level match).
People just really need to think
a little about how our bloody HEARING works! If you hear a difference it can be explained -- level, HF rolloff, phase (timing)...something
must change. It's on you
to tell us
what you think could cause that change (propose a hypothesis) and then maybe we can try to prove the device made that change!
Barring that, I'd suggest realizing that we actually know
quite a bit about how human hearing works. We have also scientifically tested
thresholds of audibility for things like, e.g., THD. Moreover, most devices these days have measurable differences in these categories that are below
these thresholds! It wasn't always the case, especially not for budget gear, and is still not
the case for speakers...but...we keep trying, lol. Y'all keep on believing it untrue, though....
Originally Posted by _tk
If the two files are 100% identical, it would support his theory of "all DAC's sound the same" (well, at least the ones that were tested). If they are not, then it would suggest that the DAC's are doing something different and that there may be a difference in how they sound.
Just because he cannot hear it doesn't mean that others cannot.
I post this because many times in this thread I see you whining about zilch "not posting the checksums"; it is as if you'd expect the only way he could prove two DACs are the same (not even sound the same, I really mean are identical) is to produce a file having the same checksum. It's simply not true, and to think so, shows exactly how much you know about digital sampling (read not much).
I will "prove" this to you by way of an analogy / thought experiment --
Let's say you had a super high-end digital camera. You put it in the blackest room in the world. You put them on a tripod (not that it matters, it's the blackest room ever, there's "nothing" to photograph) and you set the exposure time just high enough to see some noise in the image. If you snapped that camera all day long, how long do you think it'd take before two raw images (straight from the sensor data, no manipulation -- e.g., closer to PCM than say JPG would be) produced the same checksum?
Now, an ADC has "sensors" to sample the audio data, too. And there is noise in that domain, too. And, if the PCM it outputs has sufficient resolution, and the signal input to it doesn't overcome the noise-floor, where do you think that noise goes?
Fortunately, those who know anything know that while 100% bit-identical (i.e., same checksum -- which, by the way, doesn't actually guarantee
the bits are
the same; see birthday paradox / problem) obviously guarantees the two files are identical (and thus must sound identical), the converse (< 100% bit-identical must sound different) is not