From what I can understand, there is nothing we can do to design a better DAC than we have available now. Any improvement will not be audible, although we may be able to get them to consume less power. The same goes for Amps, we know what there is to know about them and there is nothing we can do to increase their fidelity.
The 16 bit 44.1 kHz format is able to record and reproduce sound waves perfectly, and no increase in sampling or bit depth is going to improve the listening experience.
So have we achieved audio perfection? Is there anything we can do to improve the experience of the listener outside of improved design of headphones? Even headphones are old technology, I'm not sure why some headphones command such high prices when we know how to make a transducer with flat frequency responses.
so you made it ^_^. welcome to the posting side of Headfi.
you have to be clear about keeping audibility and objective fidelity separated. because of course we can always make better everything that will measure better than the last one. but indeed we may come to a point where we humans fail to notice the difference. in that respect, DACs are now at a level that allow manufacturers to make something really good that will sound very much like another good DAC.
for amplifiers it depends a little on what we plug into them and how much power they have to deliver. but all in all we also have reached pretty satisfying levels of fidelity.
what makes us focus more on other part of the audio chain is not so much how good DACs and amps are and how they're all the same. what makes us focus on the rest is how bad the rest is in comparison to DACs and amps. it's just rational thinking and being aware of the magnitudes of differences. like how bad a headphone is compared to a DAC. we consider a headphone with 0.1%THD over the most of the audio range to be great. 0.1% that's 60dB below signal. if my DAC measured like that I'd throw it away.
a headphone has a messed up frequency response, even if we were to consider that the target response they pick is perfect flat for humans(which is impossible because different humans have different flat), the manufacturing variations from pairs to pairs or even often from left driver to right driver result in more deviations that most DACs would show. and I insist I'm starting with a false axiom in favor of the headphone. in practice we all require a lot of EQ before a headphone is flat to our own ear.
so it is a fact that transducers in microphones, headphones, speakers, are the weak link in a modern audio chain. and by so much that in comparison being obsessed about improving DACs can seem a little irrational.
for amplifiers we can still improve on many relevant things, like make one that can handle a wider range of headphones, or one with such a low level of noise that even with a very sensitive IEM, you won't notice any background hiss. or make sure that from one amp to the next we'll get about the same sound thanks to making sure to keep the amplifier output at a very low impedance. when does all that stop being audible is another matter, but there is nothing wrong with trying to make gears more consistent, more reliable, more compatible.
now there are many things we can improve for headphones, some are just in small increment, some would/will really change the quality of headphones. the incremental improvements are all the design work put into making lighter, stronger diaphragms, ear pads that won't drastically change the sound after we have used them for 200hours, and in general just little improvements here and there, making the headphone light yet heavy enough so that it doesn't shake itself with the music, work on making closed headphones better, so that you can improve your overall sound fidelity by lowering the ambient noise level. in the last decade I'm of the opinion that headphones have come a long way in many areas related to improving the signal we get into our ears.
other changes are more fundamental. like getting a better understanding of what flat means for a headphone. I believe that Harman research on this in the last years has been copied a lot and served to make many new headphones with a more appreciated signature for the average listener.
it's only a small step and the real good neutral sound will only come when we get customized signatures. it's a clear necessity but it clashes obviously with industrial manufacturing. also many are still working on trying to define a proper method to find out the ideal neutral for a given user. so this is something that is much more likely to come out as a digital processing than as custom headphones with the acoustic made for my very own head. but it will come, it must come if we care about good audio.
another aspect of that customization will most likely involve full HRTF compensation and solve how headphones do full left and full right stereo, instead of mixing both the way speakers do in a room. there is also many people working on such things and while they don't necessarily need to be in the headphone, they will ultimately improve the headphone.
so IMO, there is a lot to be done before we can even dare to call what we do high fidelity, and some obstacles might require to simply get rid of transducers entirely, and just send the signal straight into our brain someday. but we're not quite there yet ^_^.
same for recording, there is no limit to what we could do, the question is: will it bring any sort of benefit given the fidelity of the playback gears? like we could imagine replacing microphones in a studio with some fancy stuff like Schlieren imaging and crazy fast cameras. that would hopefully remove the influence of the microphone itself(which is limited in fidelity like any other transducers). then again maybe it's a stupid idea with massive flaws, this just came on the top of my head right now so I wouldn't bet too much money on it being the ultimate answer for recordings ^_^. but there is no limit to the amount of dudes with some ideas like I just had. sure enough one of those will be real good at some point.
and once everything else is so amazing and high fidelity that a DAC is now the weak link, then for sure we'll again be very concerned by DACs. doesn't really matter that it won't be audible, we're are who we are and we will wish to improve what can be. it just won't be important to every audiophiles.
to conclude, the way things are right now, I personally feel like all the frenzy around DACs is a little silly. because the efforts and concerns are just too disproportionate to the issues, and are far from being a priority in our modern audio chain.
I have measured DACs that can't reproduce above 10 to 11 bits accurately even though they cost over $2,000!
