"Remastered" reissues on the other formats – CD or lower-bitrate downloads – are nowadays expected to be listened to through cheap earbuds or speakers and perhaps in noisy urban environments. So, the engineer applies "loudness wars" treatment, compressing their dynamic range so the listener can still hear the quiet parts even with all the noise around them.

The other poster is not saying otherwise, though. They're just saying that "hi-def" formats, while technically unnecessary for end-user listening, are often the only way to obtain a decently-mastered recording.

There's no technical reason for things to be that way. But that's how things are.

It's sort of like buying a new car. You want the more powerful engine? Well then you also have to buy the package with heated seats, the moonroof, and the fog lights. There's no technical reason for it, but that's the only way they'll sell it to you.

It's also what this entire discussion's about.

Of course formats above 44.1/16 are useful for professional work; nobody's ever said otherwise. Just like graphics professionals work with high-res images and lossless formats even if the end product is a .jpg on a web page.

I noticed a similar thing with TV a few years ago. Despite watching a standard def. channel on a SD TV some programmes had a very noticeably better image quality. I think these had been shot and edited in HD and although the 'last mile' was still in SD there had been less degradation in the processing so the final picture was much better.

the mastering engineer has to be approved and there are some minimum dynamic range standards

also 24 bit (but not 192khz) master files have to be supplied

reportedly some of the streaming services (Spotify, YouTube) are now applying some 'loudness normalisation' which will bring some of the bad loud masters into line (it won't restore their dynamic range but will make them similar loudness to other tracks)

the loudness wars were never about what's good for listeners, but rather a competition for tracks to sound louder than other people's tracks when played consecutively on radio or in your music player

and the iTunes files are 256 kbps AACs, you can't hear the compression

remember that 'compression' in this context is data compression and not audio compression (which acts directly on the dynamic range of the source)

I can most certainly hear the compression when compared with CD digital audio.

I fully understand the difference between data compression and dynamic range (not audio) compression.

What I'm saying is, lossy data compressed audio formats are already compromised enough to rule it out as a medium for audiophile use. Worrying about the dynamic range at that point is moot. It's going to be played on tiny, terrible sounding speakers.

with 256kbps AAC, really? yeah MP3 is old and even at 320kbps it throws away everything above 18kHz (which I can't hear personally, but some people can). However AAC is newer and better and blows MP3 out of the water (so do OGG and OPUS, btw). We got a lot better at psychoacoustics since MP3 started out. I strongly doubt you could hear it in a proper A/B test.

Then, 24/192 is mostly a "weak signal" to help you estimate if the audio was treated with care.

16-bits = 2^16 * 0.01 = 655 discrete levels

24-bits = 2^24 * 0.01 = 168000 discrete levels

To help you understand, imagine 1-bit audio. What would it sound like? For each frequency, you can only have a single volume, i.e. it's maximally compressed.

I'm not sure the 1-bit extreme helps with understanding this, particularly because the audio we'd be dealing with will be a mix of many frequencies; the waveform is an aggregate of the overall 'signal' at each frequency present in the mix; this is one of the reasons why multiband rather than single-band compression has become so popular (as it allows you to get the 'max' in each frequency band rather than one band dominating the overall result of the compression).

I think there's a difference to take into account when considering any given momentary sample and the overall effect - yes, compression does reduce the dynamic range of the music, but you would need some sort of variable bit depth which was linked to the instantaneous amount of compression being applied to get any kind of workable lower-bit-depth encoding scheme, which seems like a lot of complexity for no significant gain (to me?).

> Compression means it's effectively using less of the [dynamic] range and the dynamics [range] could be represented with fewer bits in an optimal encoding.

Lower DNR can indeed be encoded with fewer bits per sample.

The meme "Math class is hard, let's go shopping" is only slightly apocryphal. Two of the voicebox lines were "Math class is tough" and "Want to go shopping?"

Because we only have 8 bits per channel, we all can see banding in (dynamically) compressed images. That's what increasing the depth improves.