To make it short: No. FLAC is in the vast majority of the cases, overkill and unneccesary. I am a big fan of lossy encoding, especially in our case here, it is the perfect end-user format: Many LPs being shared here (which is not a very accurate medium), often very old and mastered in mind of it being on a LP (and thus "deforming" the sound to accustom to the medium, not aiming at the perfect reproduction of sound in mind). The mastering is also much better than the loudness wars crap we have to deal with since the start of this Millenium, so the stress on the MP3 encoders are also less (e.g. the clipping issue at hot-mastered 0dB peaking CDs). And there is no reason to change our music afterwards - we listen to it. Period.
MP3s can actually be used for archiving, it's then called "transparency". While other say "archiving" needs to be bit-perfect. But if a LP is worn-out, it is already not "perfect", so you have "bit-perfect" copy of a worn-out and thus imperfect medium. Contradictory and pointless, innit? Who knows how the actual master tape sounded before it went to vinyl pressing facilities? Is the FLAC LP now the "real" version? So archiving your 40year old eBay'd record surely is a noble task I also profit from, but claiming it to be
THE "real" version of what the composer and engineer had in mind is basically lying to yourself as each disk is worn out differently - storage, usage, used equipment et cetera have different effects on each disc. (Obviously not a thing with CDs). An example? There was a FLAC share of the PARRY LP with "Contact Breaker" on it (122 - Videopop), a fantastic song. The MP3 version of the BMG website obviously sounded different as it's not a 40-year old LP stored in a potentionally moldy basement/attic at someone's house. So basically the FLAC of an imperfect medium is considered "perfect" for many, whilst the more accurate MP3 from the very library owner accessing the master tapes is called "unsuitable for archiving".........
Anyways, I sent every WAV and FLAC through LAME of my own settings. When I had the opportunity to get the WAVs I took my good time to read whether I want FLAC or not. And I came to the quick conclusion that MP3 (or any lossy format, but I take MP3 as synonyme) is fantastic.
To me, it is overy obvious people parrot anti-MP3 sentiments without actual hearing tests or if they do so, absolutely exaggerate their observations ("MP3 SUCKSS!!" or "DIFFERENCE IS LIKE DAY AND NIGHT"), mostly stemming from the Napster era when MP3 encoders were horrible. In fact, lossy encoding is so efficient it should be applauded for what it does. The second thing I hear is: "They take away data". What these people who say this leave out is: Years of science behind that. Removing masked bands is (almost*) like leaving out infrared images on a BluRay - You just don't need it because you can't* hear it.
Your ears are a factor, then your brain. On top of that is the medium of your choice. I often shake my head when a 256 kBit/s MP3 is frowned upon just for the sake it's an MP3 rip but the record rip is far worse. What's the point? To hear the clicks clearer? Leave alone the equipment you use. If you manage to get perfect hearing, can somehow trick your brain (confirmation bias) and have expensive equipment, then LPs are not the medium of your choice in the first place. Sorry, it's like that. So FLAC rips of *anything* is what I also prefer as base source, but audible difference are almost zero. You can see it on the spectographs - barely, but you listen with your ears, not with your eyes.
* There are frequencies shading the "surrounding" sound, but these are barely audible.
As you see, I use the term "barely" a lot. And that is what MP3 really is about. Saving literally hundreds of kBit/s that have barely any audible relevance. Frequencies are mostly intact at 256 kBit/s. MP3 files are transparent at about 200 kBit/s, the 120 kBit/s that is needed to reach the limit of the standard MP3 is more than sufficient; these bits are literally "luxury" bits so to speak for hi-hats and crash cymbals, usually my files end up having about 275 kBit/s with high frequencies going on (so not just wobbling basses). Freeform MP3 exist and allow for more bitrate by the way. OGG and AAC have almost no difference to MP3s at high bitrate (>200 kBit/s), they only excell MP3 at lower bitrates in the 128 kBit/s area - something you guys and gals don't touch anyways. Everything at 200 kBit/s sound the same. So even that is a non-issue.
*MP3-encoded files are generally considered artifact-free at bitrates at/above 192kbps.
* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.
* AAC- and Opus-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at lower bitrates than both Vorbis ogg and MP3.
Re-encoding makes no sense in future - that is what I also hear a lot. "What if in future...". MP3 is roaylty free and thus even more accessible than ever. Saving space is not needed as MP3 is already very compact, the competitors save almost nothing and sounding not much better. And even if so, I can create WAVs out of my VBR0 MP3s - which sound perfectly fine!
The reason why I like FLACs and I also had a few APEs here is that I have control over the encoder. If it's Xing or a poorly set-up FhG (e.g. in the MAGIX programs), the MP3s created are horrible and create the stigma of "MP3s sound bad". So far, everytime I had a weird-sounding hi-hat, it was apparent in the WAV too. I have a few files where the V0 VBR LAME, usually 220-260 kBit/s, is constantly using 320 kBits. The tracks are called "Circledrums" and "Line Feed" from the SONOTON album Sound Force. And I could not hear any difference. When the synthesizer kicks in, it masks the high frequencies and the encoder goes down to 290 kBit/s. If I have those files in WAV, FLAC or MP3 makes no difference, except that the other ones have information stored our brain would ignore anyways. An MP3 with proper psymodel (psycho-accoustic processing) does not need more than 320 kBit/s to sound fantastic,
BECAUSE it is using said model. It is the whole point; a MP3 still going to 800 kBit/s would be faulty and does not do what it is supposed to do.
I don't know about you people's equipment, environment (how is your furniture placed? Where are you seated while listening? et cetera), what your chain is (decoder, DACs, soundcards,...), what your hearing is and how well you are trained to find artifacts. But is it still enjoyable if you look for flaws?? Do you go into a gallery just to complain about some oil blebs on an oil painting instead of enjoying said painting?
Hydrogenaudio is very clear about my personal observations too:
Human hearing sensitivity peaks at 1 or 2 KHz, and drops from there. Children and young people under 20 years old can't hear above about 20 KHz at all, and this upper limit decreases with age. Many people can't hear anything above ~18 KHz at all, even test tones. This affords an opportunity to limit the frequencies an MP3 encoder cares about to just those that humans can hear.
The point of lossy formats like MP3 is to achieve transparency while saving space, with sacrifices made in ways that change the audio in ways that are minimally audible. Removing what is likely to be ultrasonic content is an effective way to achieve that goal. If you're not concerned about saving space, or you are determined to erroneously regard any sacrifices to the audio to be a risk to or reduction in quality, then for the peace of mind, you should not be using MP3 at all; rather, you should use a lossless format.
The characteristics of music present further reasons to lowpass the input to an MP3 encoder.
Just as you can't hear a mosquito buzzing when firing a cannon, quiet sounds are masked by louder ones. [...]
Musical instruments produce sound within the range of 40 Hz to about 16 KHz. Generally, each instrument produces a loud, relatively low-frequency fundamental tone, accompanied by numerous quieter overtones at higher frequencies. Although a few instruments (cymbals, trumpets) may produce overtones at higher frequencies, there is so little acoustic energy above 16 KHz, those tones tend to be masked by the much louder sounds at lower frequencies. Consequently, most people can't distinguish music that's missing frequencies above 16 KHz from music that isn't. When the difference is noticeable, it tends to be only in loud transients, such as percussion hits. Accordingly, well-designed MP3 encoders allow high-frequency content through only when it's sufficiently loud or would not be masked.
Again kind of a non-issue again: Either you have very clear very high frequencies which are properly encoded lossy - or it's being masked -> not fully audible anymore -> Less bitrate required for equal reproduction -> 320 kBit/s are sufficient.
About the original post: Yes, MP3s change the sound sometimes to your likings, but that is not quite the "fault" of the encoding, it's just your personal preference, similar to "LPs sound so warm" and "CDs so cold". The wrong sound - even with the mastering for LPs in mind! - of a LPs is prefered to the way more accurate reproduction of a CD. Just like some people like a violin recorded in a perfect studio environment while others want the accoustics of a concert hall/opera house.