About audio files

Sometimes I write a technical bit on the blog, hopefully not to complicated, around things I like that can tie into the Inner Child and being an adult little girl and one area is music and story recordings as apart from the pure enjoyment of, do take me back to the past.
Many of us have some sort of portable music player usually using audio files be it the one on your smartphone, tablet or a dedicated player that we can play music we might of bought from say the iTunes store, 7Digital, Amazon and others but may have physical (usually cd) recordings that we wish to 'put on' such a device and this process normally involves using a piece of software (a program) to encode files to play on your player from the disc you wish to copy from.
There are two broad types of file you can make and it is very important to understand the difference between the two.
There is the Lossless file which is designed not to remove any notes at all but instead packs the full frequencies of your music more efficiently so it takes around one and a half to twice as small a file size than your cd.
It's more like putting your clothes in a vacuum pack, switching the vacuum on and seeing them shrink - they're exactly the same as before but smaller.
There are two main brands of lossless file, the Free Lossless Audio Codec  known as Flac which is more popular and you can even buy albums ready done in and Apple Lossless Audio Codec (Alac) which is used on Apples iPods, iPhones and iPads' is the only lossless file they accept natively and can be made using the iTunes cd copying program if you need to.
If you want to make backups of your cds or do not feel comfortable with something that does remove however well designed some details of the music, then this is the very best option for you although the files will be much bigger which will affect the number you can put on a player especially if you cannot use external memory cards. Some portable players cannot accept such files so you may need to convert them from your main computer to something it can use.
Also because the files are bigger and require more processing, the battery consumption will be higher.

The second type is Lossy, which uses pyscho-acoustical scientific models based on what people actually hear to reduce the amount of information it needs to store on the basis of what (most) can't hear isn't necessary to achieve a big reduction on the size of each audio file compared to both the original cd and a Lossless file.
There are a good number of brands and variations on them but the two main ones are the (Lc) Advanced Audio Codec (AAC) used for what you buy from the iTunes music store and the grand daddy of of them all, the Mp3 that many stores such as Amazon as well as  7Digital use.
There are a good number of audio and headphone types who argue about which is best from both a subjective (what they hear from using) and objective (specifications and technical tests) way. 
The one thing I can't emphasize enough is while both can be very impressive to the point most of the time you would be unable to tell in everyday use they were lossy  files and not the original cd, that 'transparency' can and does alter occasionally for both on very challenging material and so isn't 100% transparent like the Lossless one.
In other words it's not perfect, not exactly the same as your original cd, just good enough rather like our cassette copies in the days of the original tape Walkman were although I feel actually they're better overall.

Personally while I'm happy to buy albums from the iTunes store whose quality I find is usually better than Amazon especially the 'Mastered For iTunes' titles with the blue square symbol on them when you go to buy them, I do feel there are difference in the programs supplied to make Mp3 and AAC files from your own discs.
This in my experience is certainly the case with the iTunes cd to file program having found that a straight comparison between a copy of exact same cd made using the program and a file from the same version of the album from the iTunes store (both set to 256kbs) , the store one was noticeably better (an example being the cd of Dizzy Heights by the Lightning Seeds).
It also takes, using as you should the error protection, a very long time to copy the disc as it is rare for the program to go much over 6x copying meaning it can take easily a quarter of an hour to copy compared to other programs.

There are a number of different Mp3 encoders - the thing that takes a signal from say a cd and makes the actual  Mp3  - of which the very best according to most sources is LAME and having used it, I'd wholeheartedly agree.
Lame for those interested is a recursive acronym for Lame Aint A Mp3 Encoder as although it gives you an Mp3, it doesn't use patented Mp3 bits.

Traditionally Mp3 encoders treated the stereo recording as two totally separate channels (left and right) encoding each separately even if they shared some common information so when the music got 'busy' they easily run out of bits to encode the notes to which why Mr Hifi Bore used to loath it back in the late 1990's and early 21st Century as it impaired the sound.
What by default the Lame encoder does is look at the signal to see what both what information is common to left and right and what is not and uses a combination of everyday left and right mp3 encoding and encoding what is in common (Mid=Left plus Right) and what is different (Side) where more space is allowed for the information is in common.
This is what is called Joint Stereo, literally the joining of two (in the case of the Lame encoder) ways of encoding to keep as much information for any given bit rate in the lossy file something that is done in a slightly different way in the AAC encoder Apple uses.
It uses an algorithm tested on many people to decide which frame(s) (there are 85 in a second!) would be best encoded which way which works very well.

I used it in the dbPoweramp program cos that allows me to make Flac and other files, convert between file types in batches, gives me a great number of databases for titling up music to use including classical, the ability to find album art and found it after many comparisons sounded better than the iTunes ripper (the high notes at times were muted even at 320 with that).
One I tested it at 320 kilo bites per second constant bit rate was with the Lightning Seeds cd and found the version it copied was better than both the original AAC copy and critical the iTunes Store version with plenty of transparency and no obvious artifacts.
As well, it was much more quicker going up to 25 times with error protection so you could copy more per hour! 
The small one off lifetime support fee including for the databases for me is worth it and it's an easy as pie program to use.

Settings:
Bit rates: I find I can hear a swishy sound when using the Variable Bit Rate settings even if Hydrogen Audio guys disagree with this on cymbals and the s's in vocals and do listen closely to any Mp3s offered to me done this way so keep up to date with how the latest versions sound.
I use 320 constant bite rate as it has the more room for handling complex packages and in dbPoweramp there is a slider you move to the far right to set this and a three dots for bit rate type so select constant (CBR).I find it has much  less of that 'swishy' going on (that reminds me of badly set up Dolby on cassette machines!)
This link explains more and its author's experiences match mine: Highest quality mp3 encoding guide
Advanced: there is a array of options clicking on this gives you about what modes to use.
Frankly I would leave the right hand setting at Auto for Frequency at source and also 99% of the time Channels at Auto as it uses Joint Stereo by default  (the "Joint Stereo" pull down setting isn't quite the same thing and 'Forced Joint Stereo' also degrades the sound in hard to predict ways like echo like almost mono unless you check everyone before finishing copying tens of cds at at time as learned the hard way!) only moving to Mono where you have cd that is just mono and you want to make the file as small as possibly by only using a single channel (in which instance you set 160 CBR being half the rate for  stereo (two)).
Under Encoding the default 'normal is okay but I prefer to use the Slow (High Quality) setting as that does give the very best results using 'noise shaping' for very little extra time taken.

This I found gave noticeably better sounding lossy files than using 320 in iTunes and can even be imported into the iTunes player should you need it to put on iDevices  using the obligatory software.