[Anecdotal] One example of the difference between MP3 and lossless: the "image" [1] on 256kbps MP3s is worse compared to the the original uncompressed, lossless, versions (but the listening room must be appropriately prepared to reproduce a good image).

This is a highly subjective topic. IMO we'll never reach full agreement. Personally, I listen MP3 while on-the-go and lossless music at home.

Important to keep in mind the "size" of the experiment. Two interesting quotes from the article in c't magazine:

> twelve participants would be asked to come to Hanover.

> It's true that the data we collected does not support watertight conclusions, but they do provide interesting insights.

[1] https://en.wikipedia.org/wiki/Stereo_imaging

>> twelve participants would be asked to come to Hanover.

It's a mistake to apply vanilla statistical thinking here. The 12 participants were not randomly drawn from the German population, they were extremely skewed towards enthusiasts/professionals: audio engineers, an owner of an actual Nautilus 801, someone who worked on MP3/AAC at Fraunhofer IIS, someone who works preparing masters for Deutsche Gramophon. If these are the people who have enormous difficulty distinguishing 256kbps MP3 from the CD original, I'm certainly not going to worry that I am going to miss out on anything with 256kbps MP3.

If 12 Grand Slam participants tell me they can't tell the difference between a standard $100 and a $1000 high end tennis racket, I'm not going to delude myself into thinking that it's going to make any difference for me.

It is still undetermined if having 12 highly-skilled professionals in the experiment is enough to have a conclusive experiment.

Also, this subject is so difficult to get right that the authors of the article themselves hedged by saying that experiment "does not support watertight conclusions".

The only one who was significantly able to tell if something was mp3 encoded or not, was a guy with a hearing damage who loved punk music. In fact, mp3 was developed for persons with normal hearing. So it is well possible that he was able to tell differences where other people were unable to.

It's quite easy to overprocess a digital audio file and wind up with something that is pristine as far as frequency response, but flat and 'pod people' like as far as emotive cues and intensity. Aliasing and cumulative losses to word length issues have a lot to do with it.

It's VERY easy to make digital stuff accurately represent frequencies like 2 Hz or 35kHz that our ears don't hear. It's a lot harder to make the digital stuff perform in the midrange when our perception can go, inconsistently and irregularly, waaaay beyond what we're used to thinking of as the limits.

By the way, the lossy compression algorithms don't try to produce exact frequency response but to leave out stuff that humans wouldn't hear anyway and compress the rest.

In my experience, headphones always yield the best results, and surprisingly it doesn't matter if I use the stock earbuds from my phone or a nice set of AKG over-ear headphones. It's not a matter of absolute sound quality, just the fact that you cut out room interactions and get the sound straight to your ears makes a big difference.

MP3 has some built-in flaws that no encoder can completely cover up, short sharp sounds like castanets really expose the pre-echo, harpsichord shows similar issues. It also has a tendency to make cymbals sound "washy" or "underwater", which all lossy codecs do to some degree, but MP3 is especially bad.

Still, at 192kbps I have to really focus to hear it in normal listening, but it's more or less always there even at 320kbps in problem tracks, if I really focus in on short sections. It just sounds subtly "off". But I hope no one actually listens to music like that, in short repeated sub-1 second sections to narrow in on a specific castanet snap ;-)

As for more modern codecs like Opus and AAC, it's generally completely transparent for me at 128kbps, and that's with a bit of playing it safe, I'm pretty sure I could drop Opus down to 96kbps. Modern codecs are really impressive.

I keep my music library in FLAC, both because I know it's CD quality and because it's an archive. I want to be able to convert the tracks to any new codec that may come along, if I need to.

My library is 280GB currently, and storage is cheap :-)

I understand the sentiment. But the reality is, if the re-encoding is not likely going to happen within the next 10 years, your hearing will probably have deteriorated so much that you probably won't hear the difference anymore anyway (assuming you can hear a difference today, which is a big assumption).

Thank you for confirming this! I record my analog synths that I play through headphones off an old mixing board, however when it comes through my ADC->iPad, stuff seems to get lost and I spend time adjusting the mix and ADSR for recording. Have been seriously mulling a reel to reel, but many others have had the same idea and the market prices are astronomical.

Recording should be done at 96kHz 24-bit or higher, to not have to meticulously optimize recording levels and to allow room for mixing and effects, without raising the noise floor to noticable levels.

Convert to normal CD quality as the last step before distribution.

That’s around ¾ the amount of music I carry on my iPhone :-)

However, obvious encoding artifacts abound on Spotify. Do I have a superhuman hearing?

Probably not. My hypothesis is that not everyone authors lossy files as meticulously as Fraunhofver. Also, the performance of mp3 depends on a highly linear and faithful reproduction after decoding. Mp3 is painfully obvious on crappy, processed-to-hell speaker systems like the iMac.

I think the real question is, why bother with lossy codecs? FLAC streams are lightweight by today's standards, and it's just so much simpler.

Spotify uses Ogg Vorbis, except the lowest bitrate on mobile, which is HE-ACCv2, and on Chromecast/similar devices, which get AAC (because they can't natively decode Ogg Vorbis).

It is a significantly better codec than MP3, and doesn't suffer from the pre-echo, washy cymbals and badly-encoded high frequencies. At least not until you severely decrease the bitrate.

The most common problem is when the master is hot and encodes clipped waveforms. It sounds even stranger on lossy. In fact I'm not sure if the codecs' filter banks still have perfect reconstruction in this case or if it's just a borked master. In any case, it always tends to be quite clear when I switch between lossy and lossless on Tidal.

Anyway, it's complicated and brittle, and lossless 44/16 is only something like 2x bitrate and bit-perfect (so you can write proper regression tests for codecs very easily) shrug, I think I'll go that route.

disclaimer: occasionally get paid for mastering music, so I'm wired to prefer simplicity, transparency and don't mind some redundancy in ensuring signal integrity.

What struck me though was that I couldn’t tell which was “better”.

In the track there was a section where the background drumming on one setting sounded like aluminum drum sticks while the other like wooden drumstick. Very subtle effect, and took some intense concentration to pick out.

I didn't know that was the case. Do you know why that somehow accentuates MP3 artifacts? It's not obvious to me why it would, since all the processing iMac speakers might perform is high-quality (no recompression involved). I mean, obviously the iMac isn't going to improve the MP3, it just tries to improve the speakers. But why would that make artifacts more noticeable?

If anything, don't "crappy" speakers hide MP3 artifacts, because they're not good enough to expose them?

Now if the masking sound disappears or changes, the crap is no longer masked.

In other words the psychoacoustic principles work only when we don't alter the signal too much after the codec.

Many diminutive speakers make use of techniques like multiband compression (dynamics, not entropy) to produce "larger" sound. That wreaks havoc on the psychoacoustic model of lossy codecs.

e.g. in classical music, you can tell subtle differences if you've listened the piece live or performed it inside an orchestra. However, that's a pretty edge case. There are always differences if you know where to look for, otherwise it's pretty insignificant.

Can you explain this a bit more? How is having heard a piece live, which by definition means a unique performance, going to affect whether or not you can pick out whether the recording of (likely) a different performance has been put through lossy compression? Or do you mean a recording of that same live performance?

I mean I'm used to subtle differences coming and going depending on room/speakers/crappy compression, but only because I use the same source as reference (say, the same CD). Using a live performance as reference sounds strange, because there I would be able to here one of the musicians doing something different, but difference isn't there on another recording so not usable as cue for hearing differences in sound reproduction.

As you know, classical music is layered. It can be scaled for different sized orchestras, which can be akin to tessellation in graphics. You can add more nuanced scores or details if your orchestra has enough members. Of course this has a limit, which is the full score written by the original composer. Similarly, you can remove some layers or simplify the piece if you're smaller orchestra without compromising the piece.

What I tried to say is, if you've listened the piece from or performed with a relatively big orchestra, you'll know that which instrument shall be there, where the small optional triplets are, how the piece should sound or where's that little oboe shall come in, where the little cymbal adds that little crash, or how the harmonics affect each other and create that atmosphere.

So, you'll notice something is missing or off or not as it should be especially in the high end. Classical music has a lot of perceptual tricks under its sleeves to create a specific ambiance and sense of space and most of this lays in the higher end of the spectrum, and they get shaved off first with lossy compression.

Hope this helps, because it's something more felt than can be said with words, how you can't really hear the double bass but feel how it's there. It's that kind of perception.

Edit: Just wanted to add that one musician's or orchestra's specific style of course will be different, but a good orchestra is very faithful to the original score of the piece. Even if an orchestra is playing a little fast or more aggressive, or a simplified version, base instrumentation and atmosphere is the same (as long as the orchestra is not doing Metallica S&M style play the right thing with wrong instruments kind of deliberate arrangement).

Another extreme example would be the band Pink Martini. They have an on-stage audio magic which allows them live with the exact sound of their studio recordings, albeit live. It's surreal to experience.

The thing I'm looking is musical dynamics rather than details itself, but it's equally lost with poor recording and mastering as you say, since they're also captured by the microphones. The thing I'm trying to explain was they are not "finer details" like "oh! I hear the bow of that player", but a bigger feeling that the orchestra creates by playing together, and that effect is independent from individual instruments, most of the time.

It's a somewhat difficult concept to put into words and explain. It's more about feeling the music and decoding the brain, and I think it needs some experience. Being unable to translate this into words makes me sad, because it carries music to another dimension IMHO.

Don't worry I understand what you mean wrt dynamics etc, it's just that I'd never thought of linking it to lossy compression, because there are so many other things which make it hard to reproduce that live sound.

How does a live performance that you hear with your ears at a specific place in a room help you pick out missing parts in a different recording, played by different people in a different place, recorded with multiple mics and then mixed and mastered?

Of course, this might be utter nonsense, and I will bow to bayindirh's judgement on that!

That'll definitely help with hearing differences between two tracks. But i don't think you can compare live music to recorded tracks. Especially acoustic instruments, the room is such a big factor with those.

I guess that also teaches your ears to identify differences in other situations more clearly.

That's what mixing and mastering engineers practice their whole career and get really good at.

In a proper concert hall, sound is expected to be homogenous, so you should be able listen to the orchestra equally well, with the same sound balance (or mix) regardless of the place you sit. Similarly, recordings are done from suspended or positioned (and ideally tuned) mics, so you can capture the orchestra as someone sitting in the audience. At least this is how our performances were recorded.

The mastering is then done to match the recorded sound to the hall's sound, and balance any imperfections or clean the orchestra's inner talk between pieces (yes, we communicate a lot :D ).

When you listen an orchestra live, you will have a lossless blueprint of the piece in your mind (track by track if you can separate the instruments). If you can get a recording of the same performance, you can compare it with the live performance. That's absolutely correct.

But if you listen to a recording of a different orchestra playing the same piece, the arrangement and instrumentation will be same (you may have 8 violins instead of 12 but, violins won't be changed by violas most of the time). So, the atmosphere of the piece will be the same. Assuming the recording is done by competent folks, the spectrum would be the same (~20Hz -> ~20Khz roughly).

After some point, even if you're listening to a different orchestra, you can start to point to the things that should be there. It's very hard to describe, but every instrument has a base sound and details on top of it (you can tell they're all trumpets, but different brands or models. Similarly you can tell they're double basses but they're different in some ways). That base sound starts to erode too when you have a lossy compression, and in turn it affects the sound of the piece, regardless of the finer details (which are mostly affected by resins, bows, styles, etc.).

It's a "these two instruments shouldn't interact like this in this piece. Something is missing!" kind of feeling. This missing part is either something at the high or low end, almost an harmonic. It's not noticeable unless you're looking for it, but it's there.

That difference can be clearly heard by re-encoding a FLAC as a high bitrate MP3 and taking their differences. It's a hiss-like sound by contains a lot of the said harmonics and you can almost listen to the piece just by listening to it. Someone did that and published the differences, but it was some years ago. I'm not sure I can replicate or find the article. That article took differences of the exact same recording but, it can be applied by your brain to different recordings after some time.

Hope I've succeeded to clarify it somewhat. It's something very hard to describe by words. Please ask more questions if you want to. :) I'd be happy to try more.

Comparing two orchestras can be similar to comparing a recording in MP3 to FLAC.

I think i get the point in that learning to listen to those details and recognize frequencies can enhance your ability to spot differences in encoded audio.

In turn this creates a vast network which allows you further decode the music you're listening. This is how one learns to feel the music.

But that has absolutely nothing to do with compression. All that would matter is whether you're missing the "nuance" or "layers" that are there on an uncompressed CD, but that you would perceive to be gone in MP3.

I've performed and listened to a ton of classical music in my life, and I've never heard a difference in what you're talking about between CD's and MP3's. It doesn't really make any sense in terms of how MP3 compression works, either -- the compression artifacts it introduces are pretty orthogonal to nuance in classical music. at 128+ kbps

It sounds to me like you're describing the difference between a live concert and an uncompressed stereo recording, no matter how well it was mastered.

It is a very physically beautiful headphone but in terms of sound, it's kind of warm with a slight haze and indistinctness in the treble. That might be pleasant for some people, but I think any modern electrostat like the L700 or SR009 would outperform it significantly if you put them side by side. I assume its value is due mostly to its rarity.