If you are able to do this, who says it’s the distortion difference that makes it audible?
Here's a fun story: When I was four and starting kindergarten, an audiologist came to check our hearing. I don't know why, but probably to find any kids with hearing issues that parents weren't aware of and so didn't tell the school. The audiologist brought a tone generating machine with her, and put it on a table. It was a simple machine with maybe 3 or 4 knobs and a few switches - couple holes for headphones. The test was, we had to put the headphones on and the audiologist would make the machine make a sound and we had to tell her when we could hear it. When Ms. Audiologist turned the dial to 1, I heard the tone: probably 2kHz or so. It was clear, in both ears. I told her I could hear it, and immediately I could tell she didn't believe me. She asked me "in which ear?", and I told her "both". She then said to me "you don't hear it, you watched me turn the dial!" she went on to tell me that lying was bad and acted annoyed and told some other person there (I think it was the teacher's assistant or something -IDK it was a long time ago). Anyway, she then turned the dial to 2, and I told her it was louder. She said I was lying again because "nobody hears it this quiet". Then she told me to stop looking at the machine. I don't know why she didn't just turn the thing so I couldn't see it and then ask me when I could hear the tones if she didn't trust me, but she didn't. Anyway... I let the wench get to 4 and told her I could hear it then. She checked both ears and then that was that! I guess if literally nobody ever hears 1, and 2 is extremely rare, and 3 is great, then she's probably not going to believe a 4 year old. IMO she could've been a little less accusatory about it. Anyway, there's another anecdote- my hearing is exceptional...
You might ask me why I remember this... I think it's because it's one of my first emotional memories of me, solo, in the world. Emotional? Yeah! An adult was accusing me of being dishonest, and she did it
repeatedly. Since I am (and have always been) an honorable person, it cut me deep. Obviously I have more life experience now, so being called a liar doesn't affect me as much (I won't remember it decades later...). If I knew a bit more then, I would've made that dang audiologist turn the machine so I couldn't see it, or I would've turned myself around so I couldn't see it - demonstrated my ability and truthfulness, and she could feel however she'd feel about it (you can't make anyone feel shame - shame comes from within)
To answer, though - I do think that it's either a combination of THD and x, or a product of THD which is responsible. Whatever the case, though, THD is generally a pretty good indicator for what's going to sound clearer than what. Not always though... I have one example: I have an SMSL m100 DAC which is spec'd to be around -100dB THD+n. I measured it myself with my Babyface Pro to be between -99 and -100. It should sound better and more detailed than a [n otherwise really well designed] DAC that's -94dB THD+n. But no - it's not! The Arcam rDAC, -94dB THD+n, beats the m100 in clarity and imaging (stage is wider). There's nothing specifically
wrong with how the m100 sounds, it is the opposite of engaging, though - and worse in the ways I described the rDAC being better.
Nobody accused you of lying. You think the difference is real. Without any controls and proper testing, that isn’t surprising.
Of course I've done testing, just not double blind. I've done blind tests, and they've (obviously) been witnessed...
This is anecdotal, but: on so many occasions, my system has sounded off to me, and when I've checked the settings, nearly always there's a reason!
On the other side of that... I almost never find something to be off when I'm randomly in the settings. I don't want you to take this as a reason, just as part of the larger picture that is my understanding of the capability of my hearing.
As for proving online, you can use a proxy to check how well you do in detection distortion:
www.klippel.de
Give it a go, it’s usually very humbling.
That's a crap test... I tried two songs and they're
majorly distorted. On top of that, they lack high frequency information above 7kHz. And additionally, backup vocals and instruments are
severely lacking fidelity... The designers of that test are obviously disingenuous. I don't know their motivation for being so, but it's obvious to me that they are. Disingenuous because they're not incompetent. Unless it's nepotism's fault (some guy's nephew got to make the project?)
I wouldn't expect
anyone to get past -40. Even with excellent gear with proper room treatment and genuine desire to hit -80+
So I'm not "humbled" by the test - the tracks were cherry-picked to hide distortion! I think I mentioned somewhere in this thread that some songs are a lot easier easier to judge the sound quality of a DAC with than others. To elaborate, usually tracks mixed analog on multi-track tape, on an either ageing or less-than-state-of-the-art machine aren't the best... Cheap mics and primitive compression also contribute to unworthiness... Unless the tape part of the chain is transparent enough that the limited frequency response of, say, the mic on one of the cymbals, is fully captured and thus becomes a character of the track, instead of just horrible on top of horrible and you can't tell where any of it came from! There are exceptions though - and just like when it doesn't sound right when you try to put ZZ Top Afterburner or Judas Priest Painkiller onto a tape (especially Normal bias), the opposite can also be true. It is less common, though.
For this test I was using $25 earbuds... but they're clean! All they need to sound balanced is a gradual increase from 0 to +3dB from 9 to 17kHz, and +5dB in the 40-60Hz range, falling gradually from +5dB to 0 from 60 to 105Hz. They're not quite linear that way, but their harmonic distortion? Absolute
gems! I'd put 'em up against any earbud:
If you give them 60Hz and then turn up the volume until your eardrums are like "NOOO!!!!" (yes, they go that loud...) and then you lower the frequency to 23/24Hz to listen for the ultra-low rumble that is 47Hz from the 2nd harmonic,
it's literally not there. No third harmonic at 69-72Hz either! Think of how far that 15mm driver has to be moving for 60Hz to literally hurt your ear (it's not a sealed earbud...), and then then think of how much farther it moves at 23Hz.. Then reflect on the fact there was no earth-shaking 47Hz with so much 23Hz!
I can't say for sure how far up the registers this exceptional performance carries, but they're definitely clean enough to discern -30
Humor me: Pretend Klippel was evil. What do they have to gain from convincing people that 1% THD and less is meaningless?
