What is Mastering?

[seismic1]

mp3 encoding can introduce artefacts into the music. These artefacts are not restricted to any particular part of the frequency spectrum. In general, said artefacts will be less apparent the higher the bitrate used to generate the compression. I can definitely hear the effects of this compression on mp3 files generated at 128Kbps or lower, and quite often at higher settings than this. It's quite easy to test yourselves. Any mp3 converter should allow you to set the bitrate and generate multiple bitrate representations of the same data.

I upload 192Kbps files to my free kiwi6 account. I use this bitrate in order to maximise the amount of downloads I can get from this free account without crossing the threshold into the paid account category. This bitrate is fine for most purposes, but I have found that these files can be quite tiring to listen to on my HiFi for long periods.

I upload 320Kbps mp3 files to SoundCloud. These files generally sound very good on my home system, but I have noticed rare occasions where strange effects become apparent after encoding. These effects are repeatable when using the same codec. Anybody downloading one of my SoundCloud files will get the 320Kbps version. Note that the streaming SoundCloud player produces a 128Kbps representation of your uploaded files (whatever the format. It is often possible to hear things in the streaming SoundCloud player which are not present in the uploaded file. These effects are most easily audible in (but are not limited to) the high and low frequency spectrum bands. Another worry which I have concerns the conversion of mp3 files to mp3 files. If you think about it, it's quite obvious. mp3 is a "lossy" compression, so generating a 320Kbps mp3 from a wav file will result in data loss of some kind. Generating a 128Kbps mp3 file directly from a wav file will NOT produce the same results as generating a 128Kbps mp3 file from a 320Kbps mp3 file which was originally spawned by the same wav file, as data loss will occur twice during the process.

This is why Bandcamp (whose streaming player is also 128Kbps, I believe) allows you to select wav or flac (a lossless compressed format) as a downloadable format so that the audio can be enjoyed in its original glory.

[Negative Spectrum]

what if i do not hear the difference between .wav and .mp3? i definetly hear nothing above 14.5kHz.

so maybe the whole music i make sounds dull and i don't know it because i can't hear it :uh:

I don't think your music sounds dull, quite the opposite in fact. I think the general music listening populous has become so used to mp3 encoding that they no longer "notice" the artefacts. Given the choice I listen in .flac (primarily because the files are smaller than .wav),

Try out the exercises on the page I linked above and see if you can hear the differences.

[Ahornberg]

i tried out those excercises and i did not hear the diffs :( but maybe that is good news because i see every jpg-artefact in a digital photo and that is something driving me crazy. so in not hearing the mp3-artefacts there will be one problem less in my life :biggrin:

however, i go more and more in using flac-files ...

[Sky High Diamonds]

Personal choice. To compress/not to compress, mp3, wav. Aiff. All contenders in ' The Loudness War' which is an interesting debate in itself: http://turnmeup.org


Great to hear such thoughtful views. I'm sat on the fence with it but do think that so many people are listening to high quality recordings on low quality equipment and that has to make a massive difference to what they actually hear and process.

[Cloud Hunter]

But I do agree with Ahornberg's first post: I think using multitracks to refine the music is a better choice than the final stereo mix. I've just been playing around with my compressor tool, and all I can do with it is make things uncomfortably louder, annoying when applying it to a quiet track. If I am satisfied with the mix, do I still need to master it?

[seismic1]

If you're satisfied with the mix, then it's up to you. Mastering is not just about compression/loudness. You could try some gentle saturation, some imaging. I've just bought myself a new mastering EQ. I have found that mastering is worthwhile, but it took me a long time to arrive at a setup that delivered half-decent results. If you are working on different musical styles/genres, you are going to need multiple setups, and again, these are just basic templates which require individual tweaking for each piece of music.