What is MPC?
MPC (also known as musepack) is a lossy audio format, like the well known mp3 (or Ogg). What makes MPC special is that it was designed and tuned by audiophiles with transparency as the only objective.
What is transparency?
When an compressed audio file is indistinguishable from the original, then we say it is "transparent". Transparency is highly subjective and depends on the listener and the audio equipment used, meaning that a quality 3 mpc would probably be "transparent" while using laptop speakers. But when we say "this or that is transparent" we mean that very experienced (and specifically trained) listeners with high quality audio equipment have been unable to ABX them.
What is this ABX and ABXing thing?
ABX tests are also known as "blind" tests, because the listener tries to discern between two samples without actually knowing wich one he is listening to, thus eliminating the possible placebo effect.
ABX tests are the only objective way to determine audio quality. They are necessary because the well known placebo effect, that will make you hearing differences that don't exist just because you think they should be there, no matter what you are actually hearing.
If you want to learn more about ABX tests, you can find specific tools and information here www.pcabx.com, www.kikeg.arrakis.es/winabx, ff123.net/abchr/abchr.html
The excellent player foobar2000 also have an integrated ABX utility.
Does MPC --quality 5 sound any better than mp3 --alt-preset standard?
No. Both will sound exactly the same to your ears. Because both are transparent on most cases. Preset standard mp3s are transparent (indistinguishable from the oirginal) on 99.5% of the music. Quality 5 mpcs are transparent on 99.999% of the music. Chances are you won't hear any difference.
What makes MPC better then?
MPC is the most efficient lossy codec available. This means that MPCs will be transparent with less filesize than any other existent codec. For example, the --alt-preset standard mp3 will be about a 30% bigger than mpc q5 to obtain the same quality (transparency). MPC is also less prone to artifacts than other lossy audio codecs. MPC also uses the best tagging system around (APE 2.0) and has perfect support of replaygain.
What is an artifact?
When the encoder makes an audible mistake, we call it an "artifact". This could be a tonal, distortion, noise or articulation difference, pre-echo or even a loudness drop. You do need to train yourself with a lot of ABX tests in order to be able to hear those kind of things.
What is replaygain?
Replaygain is a nice program that will level the volume of your mpc collection. Different albums have different loudness, so if you want to avoid being forced to crank up and down the volume with each song, you better use it. Replaygain's target is 89 dB. You can make all your music to sound at 89 dB (track gain, aka "radio") or you can preserve relative loudness differences within the same album and make it sound at average 89 dB (album gain, aka "audiophile").
Replaygain is also used in conjunction with the --xlevel switch to avoid clipping. That's why you should always use --quality 5 --xlevel. (with future SV8 version it won't be needed).
Will replaygain modify my MPCs?
No, it won't. MPC stores replaygain information (track gain, album gain, track peak and album peak) on the APE tag. You can make your player to either use this information or ignore it. So, if your player is enabled to use replaygain info, it will crank up/down the volume for you, but the mpc file itself will not be modified.
Why use just quality 5? I've seen that many people uses higher quality settings.
As you should know by now, MPC was designed with transparency as only objective. Quality 5 is where transparency is reached, so higher quality settings won't make any quality improvement. MPC at quality 5 takes all the bits it needs to be transparent. With higher quality settings it increasingly takes more than needed.
Why are there then? Shouldn't they provide more safety against artifacts?
Those settings are there because it is easy to implement them, not because they are needed at all. Let me say it again: quality settings above 5 will not make your MPCs any better.
Why? because on the extremely rare occasions where MPC fails, it's because the psymodel is not able to allocate bits where needed, not because it needs more bits. So the psymodel will also be unable to allocate those extra bits that higher quality settings provide. Those bits are always wasted and don't provide any extra safety.
Huh?
If you can ABX a quality 5 mpc, I bet you 100€ that it will also be ABXable at quality 8.
What about transcoding? Wouldn't they give me more quality?
Well, theoretically they should... but in practice, not. If you want to transcode your MPCs to low bitrate mp3s, like ABR 128 (or even 160 or --preset medium) for portable use, then the difference between q5 and q8 transcodes is nil.
But I really need to transcode to high quality mp3, what about that?
If you desperately need to transcode to high quality mp3, like --alt-preset standard, then some audible differences could appear between q5 and q6 transcodes. Further quality increases won't have any impact.
But let me tell you that if tou really need those high quality mp3s, then you should be sharing mp3s from the very beginning.
Another solution for the people that needs perfect quality and the possibility to transcode later to whatever they want are the lossless codecs.
What is a lossless codec?
Zip and Rar like programs specifically tuned to compress audio WAVs without any loss. They will produce really big files tough (about 57% of the original size). For example, The Cure - Seventeen Seconds "weights" exactly 360 MB, we can bring it down to 183 MB using Monkey's Audio (one of the best lossless codecs around). You can decode the .ape (Monkey's Audio file extension) back to WAV and you will have exactly the original WAV (bit per bit). This is very useful if you want the ultimate quality and the possibility to transcode in the future to whatever format you want without any quality loss.
That sounds good, why don't you share lossless then?
Because we can achieve the exactly the same audio quality (transparent) compressing the album with MPC --quality 5 --xlevel, at just 46.2 MB. And we love that.
So, what settings should I use on my rips?
Well, that is easy: --quality 5 --xlevel
Should I replaygain, tag or something to adequate to a standard or something?
No, we don't want to enforce the use of any kind of "standard" other than common sense. But many people really appreciates the log file that EAC generates after extraction. EAC is well known as the best digital audio extraction program around, and people likes to know that their dowloads were properly ripped. The EAC log is like some guarantee of that.
But while EAC is a great program, it is not available for non Windows users. Linux users should use CDParanoia, which is their safest option. Windows users have also other interesting alternatives to EAC, like CDex (uses the CDParanoia routines), the Plextools (for Plextor drives users) or AccurateRip (dBpowerAMP, right now is the best tool one can use to determine a drive reading offset).
How to encode those great MPCs by myself?
There are plenty of guides for using EAC to encode MPC. All you have to do is ignore the quality setting they recommend and stick to --quality 5 --xlevel.
Are you sure?
Yes.