Part 2 - Making Your Computer an Audiophile-Quality Music Player

HOW TO GET THE BEST SOUND QUALITY FROM ITUNES

Now that you know from Part 1 how to import or purchase full quality audio files, the next step is to get the best sound from the basic iTunes app itself. There are settings in iTunes that will degrade the playback quality and should be defeated when you want totally accurate sound. It's O.K. to use them for casual listening, parties etc. if that works best, but this is what to do when you want to hear things right. When all of these steps are followed, iTunes is actually a bit-perfect 16 or 24 bit digital audio player. These steps apply to Mac computers. It is much more difficult to get bit perfect audio from a PC. You need to do these 4 steps and more. For that I'd suggest a google search.

THIS IS WHAT TO DO IF YOU'RE ONLY INTERESTED IN PLAYING CD-QUALITY AUDIO FILES (44.1K/16 BIT)

Most music lovers will be more than satisfied with CD-quality once they rip their CD collection properly or begin purchasing 44.1k/16 bit downloads. These 4 easy steps cover what to do so iTunes itself isn't affecting the sound quality. If you're interested in high-definition audio (48k, 88.2k or 96k/24 bit), you have to do these four plus step 5.

STEP 1 - Launch iTunes, open preferences and select 'Playback' at the top. Make sure 'Sound Enhancer' and 'Sound Check' are NOT turned on, then click 'OK'. The 'Crossfade' feature will not hurt anything if you like it.

STEP 2 - Under the 'Window' pulldown menu at the top of iTunes select 'Equalizer'. Uncheck it, and to be safe set the Preset menu to 'Flat', then close the window.

STEP 3 - At the top of the iTunes screen, set the volume control all the way to the right. If you are feeding the computer's analog audio output jack to your hi-fi system or powered speakers, the computer's volume control should also be all the way up. You should adjust the volume from your system or speakers, not iTunes or the computer. If you're listening on headphones from the computer's headphone jack, or if your powered speakers don't have volume controls, use the computer's volume control, not the iTunes volume control.

STEP 4 - To complicate things, you can also adjust volumes per song or per album. If you have never done this, don't worry about it, there's nothing to undo. If you have made volume adjustments to individual songs or albums, do this: Highlight an album on which you've made volume adjustments and 'Get Info'. You'll be asked if you want to edit multiple songs, click 'Yes', then click 'Options' at the top of the info window. You'll see a slider for volume adjustment. Leave it set at 'None' and check it, then click O.K. All of the songs on the album will be reset for no volume adjustment.

That's it for regular CD-quality audio files. Proceed to Step 5 if you're interested in playing high-definition audio files (48k, 88.2k or 96k/24 bit AIFF, WAV or Apple Lossless).

STEP 5 - Even if you knew that iTunes can play high-definition 24 bit files up to 96khz, there's something devious going on under the hood that you may not be aware of. When you are listening to any audio media player like iTunes, you are listening to an 'audio engine'. iTunes manages your music library, and provides the DSP functions we defeated in steps 1 - 4. But in Mac computers, the audio engine you are listening to is the QuickTime player. The little secret to this is, you need to set QuickTime's sample rate to match the sample rate of the file you're playing. The default setting is 44.1k, the standard rate for CD-quality files. And that's why you don't need to mess with this if all you'll be playing is 44.1k/16 bit files. But if you play an audio file with a sample rate that does not mot match QuickTime's setting, QuickTime does a rather awful internal sample rate conversion to whatever rate it is set for. So if you don't know how to do this, the extra money you spent for 96/24 downloads was wasted - it will sound worse than the same song as an mp3 if Quick Time is sample rate converting it. Here's how to set QuickTime's sample rate:

In your utilities folder launch the "Audio MIDI Setup" app. Highlight 'Built-In Output'. On the right you'll see pulldown menus for setting sample rate and bit depth. Set the sample rate to match the audio files you're about to play and bit depth to 24 bit. When you go back to playing 44.1k/16 bit lossless or mp3/AAC's, it's still recommended to leave the bit rate at 24 bit. As a side note, any mp3 or AAC that you've purchased will be 44.1k. They can be 48k, but that is very rare.

The following screen captures show how good - and bad - iTunes can be depending on preferences and QuickTime settings:

A 48k 24-bit 10kHz sine wave played through iTunes with QuickTime sample rate set to 48k and bit depth to 24 bit, iTunes DSP defeated and volume control at 100%. The tone shows as a pure spike at 10kHz with no artifacts around it. This is a bit-accurate reproduction of the tone.

A 48k, 24-bit 10 kHz sine wave played through iTunes with QuickTime set to 44.1k, 16 bit. All audio energy outside of 10 kHz is due to distortion caused by the QuickTime sample rate conversion and truncation. 

IF YOU WANT THE DETAILS, HERE'S WHY YOU DEFEATED THE FUNCTIONS IN STEPS 1 - 4
Each feature we disabled is a DSP, or Digital Signal Processor. Each of these will degrade the signal quality to one degree or another. The worst offender is 'Sound Enhancer', which is a pretty awful 'spacial expander'. This makes the music sound as though it is coming from outside of the L/R speakers, creating a much larger sound field. Even though it may wow you when you first hear it, it is highly distorted and not at all accurate.

The EQ is the second worst offender. Even quality eq's add phase distortion, and this is not a quality eq. If you have a decent hi-fi system, especially if it's a good analog preamp or receiver, its eq should be much better.

The master volume control, individual song/album volumes and the Sound Check feature degrade the signal the least. But even bringing the master volume down the smallest amount will cause a digital distortion called 'truncation distortion'. This will be most noticeable on mp3's or AAC's, a little less so on 16 bit lossless or lossless-compression audio files, and barely perceptible on 24 bit files. If you want to use the individual song or album volume adjustments, you should still leave the master volume all the way up; a combination of the two will degrade the audio much worse than using only one.

The Sound Check feature is a rather clumsy attempt at matching the volumes of songs between older vintage CDs and newer ones. Any music produced or remastered after 1995 is usually much louder than music released prior to that. This shouldn't matter if you're sitting down to listen critically to an album, just turn it up as loud as you want. But for parties or casual shuffle-play listening it ca be distracting, so that's a good time to use the feature. You'll soon be hearing of a much more accurate method of matching 'perceived' volumes.

That's all for Part 2. Part 3 will address how to improve the quality of your digital-to-analog convertor over what is built into the computer, which is where we really start getting into the audiophile side of things.

Part 1 - Making Your Computer an Audiophile-Quality Music Player

Even though this subject is for music lovers who are not necessarily involved in music production, I think it is important information for music professionals as well. Whether you produce, engineer, or are 'just the musician', the better trained your ears are, the better your musical output will be. And having a trained ear involves listening to music in true high-definition. Also for vinyl lovers, this is how you can learn to love digital just as much.

Most people still listen to music on their computer through earbuds, internal speakers, or small external speakers. For serious listening they have the big entertainment system, and they may have an iPod/iPhone dock so they can play their iTunes library. But there is a growing trend of integrating the computer into the entertainment system as a main source for music (and video). Truthfully the majority of people love it. But almost everyone who is somewhat of an audiophile, especially vinyl lovers, like what they hear from the computer or iPod dock even less than CD's. We're going to talk about why that is and how it can easily be fixed. And it can be done in surprisingly affordable steps, the basic ones costing nothing but a little time.

One reason most vinyl-lovers don't like the sound of digital is that they've never really heard CD's reproduced properly and with really good converters. And even more likely they've never heard high-resolution digital audio, which is much better than CD quality. In fact, a large number of analog-only guys have come over to the digital side after hearing high-resolution digital properly reproduced. I'm not going to get in depth about your choice of speakers, amps, preamp vs. receiver etc. etc., though I will make some important points about that at the end of the final part 4. My focus will be on how to improve your computer's audio-media player (iTunes etc.), how it's going to convert digital to analog, and what kind of audio files you're feeding it.

I will be talking specifically about how to use and improve iTunes, but almost everything I'll talk about you'll find in Windows Media Player and others. I am not going to be crazy technical, except in a few cases where I'll warn you in advance. Otherwise I think anyone will understand this. So you don't get too beat up, I'll do this in four parts that you can digest one at a time before I post the next. And each successive part will make a little more improvement in your sound. This first step of part 1 involving audio files may bore audio pros who probably already know most it, but I promise you in parts 2, 3 and 4 you'll learn something you didn't know.

In part 1 we'll cover four steps:

Step 1 - Understanding digital audio file formats.

Step 2 - Importing CD's into iTunes without losing sound quality.

Step 3 - Dealing with the iPod, iPhone and mp3 players.

Step 4 - Obtaining high-definition digital audio files that are better than CD-quality.

STEP 1 - UNDERSTANDING DIGITAL AUDIO FILE FORMATS

We're not going to get overly technical, but it's important to know at least a little about audio files. If you're interested in high-quality sound, it's important to know which digital audio file formats deliver the best fidelity. Despite all the improvements I'll suggest you make to your audio player and system, all they can do is reproduce what they're fed, and if it's garbage in, it's garbage out.

The first thing to know is that we have all been sold down the river by having the data-compressed formats mp3 and m4a (iTunes AAC) crammed down our throats as the 'future of digital audio'. The ONLY advantage these files have over full quality files is they are much smaller - about 10% to 20% the size of a CD-quality audio file. But you lose considerable fidelity, which probably isn't apparent if you're listening on standard-issue earbuds or computer speakers, but on a good system it's obvious it's not right.

These formats were pushed on us for two reasons; around 1998 when mp3 was introduced large hard drives were very costly, and internet speed was comparatively slow, so mp3 player manufacturers could brag about how many songs you could store without using a lot of space, and how quickly you could download a song. But now that large hard drives are so inexpensive, and internet speeds much faster, there is no reason to data-compress your main music library. The first mistake we're correcting is sacrificing the quality of your main music library just so you can get 2000 songs on your iPod. As you'll see, you can still do that if you want, but it can be done without ruining your main music library on the computer. Even though your mp3's and AAC's played from iTunes will sound better on your hi-fi after you make my suggested improvements, you're not really going to get audiophile-quality sound until you're listening to at least CD quality files, and eventually better. And if you don't think CD's really sound better than mp3's, you'll change your mind once you hear the difference on your improved system.

THE BASICS YOU SHOULD KNOW ABOUT DIGITAL AUDIO FILES

1. Lossless Files

A lossless audio file is a full quality, full size audio file. AIFF and WAV are the two types of lossless audio files you will be seeing. They have been standards in professional production and broadcast since the 70's. The audio tracks on a CD are WAV files. The quality of a lossless file can be determined by its 'sample rate' and 'resolution', also called 'bit depth'. No need to worry about what that means, but it's simple to understand the numbers. The audio files on a CD are ALWAYS 44.1k sample rate, 16 bit resolution, which is indicated as '44.1k/16' or simply '44.1/16'. You will see only two bit depths in consumer audio - 16 and 24 bits. But sample rates can be 44.1k, 48k, 88.2k, 96k, 176.4k and 192k! With a few caveats, the higher these numbers are, the better quality the sound will be. Also the higher the numbers, the larger the file. There is no difference in sound quality between an AIFF and a WAV file. Most audio media players like iTunes and Windows Media Player can play both AIFF and WAV. We'll get into specifics about that and iPods later.

2. Lossy-Compression Files

mp3 and m4a (iTunes AAC) are 'lossy-compression' audio files. They are much smaller than full quality files - normally 10% to 20% the size - because a lot of the data is discarded, meaning the file has been 'compressed', at the expense of sound quality. You will see these files rated in numbers that indicate their 'bit rate'. For instance, 256kbps is the bit rate for the standard iTunes+ AAC. Before that, the standard was 128kbps. The higher the bit rate, the better the sound quality and the larger the file. But even the highest bit rate AAC or mp3, which is 320kbps, is still not as good as a full CD-quality file.

By comparison to WAV's and AIF's, mp3's and AAC's can be either 44.1k or 48k. All music available as downloads from music retailers in mp3 or AAC formats are 44.1k. 48k is very rare.

3. Lossless-Compression Files

'Lossless-Compression' files use around half to two-thirds the space of AIFF and WAV, but unlike mp3 and AAC the compression is done in a way that does not harm the sound quality. They are rated by the same number system as lossless files (44.1/16 etc.). The one you will see in iTunes is Apple Lossless (ALAC), and for reasons we'll discuss later this is probably the best format for home hi-fi use for now. The lossless-compression format that seems to be gaining the most popularity is FLAC. iTunes cannot play FLAC files directly yet, but it's rumored it soon will. If you create some Apple Lossless files from your CD's now, and then FLAC files later when iTunes supports it, they are completely compatible and iTunes will play from one to the other with no problem. There is no difference in sound quality between the two, but FLAC files are adjustable and can be made almost half the size of the equivalent lossless file, while ALAC's are fixed and are usually a little less than 2/3 the size of a lossless file. 

The reason some don't like using lossless-compression files is that AIFF and WAV are long-established standards that you can be sure will be playable by systems for decades to come, but not everything can play Apple Lossless or FLAC. Media Player can play FLAC but not Apple Lossless. iTunes can only play FLAC with a third party plug-in at this time. However, you can download free utilities that will convert Apple Lossless or FLAC files back into full AIFF or WAV files if you run into compatibility problems.

Many are surprised to discover that iPods/iPhones can play AIFF, WAV and Apple Lossless files. You'll find the details below. Many mp3 players can also play lossless and lossless-compression files. You'll need to check your player's spec sheet.

The next step is to get at least your favorite, most listened to CD's into your computer without harming the sound quality. Here's how to do that:

STEP 2 - IMPORTING YOUR CD'S INTO ITUNES WITHOUT LOSING QUALITY

If you don't care about details, just do this:

Insert a CD and open it in iTunes. At the bottom right click the 'Import Settings' button, which you'll also find under preferences. In this window you'll see an 'Import Using' menu. Set this to 'Apple Lossless Encoder'. At the bottom is a checkbox for selecting error correction. Even though it takes longer, this is the best setting for any file format including mp3 and AAC, especially for ripping in older scratched CD's.

If you'd prefer to use AIFF or WAV, select it in the 'Import Using' menu. You'll then see a second 'Settings' menu. Set this to 'Automatic' and turn on the error correction.

That's it! You are now importing your music without losing sound quality, but you are using a LOT more hard drive space. Here's a comparison (approximates):

For one hour of music -
44.1k/16 (CD-quality) lossless files use 650MB.
44.1k/16 lossless-compression files use 325 - 450MB.

256kbps lossy-compression files use 130MB.
128kbps lossy-compression files use 65MB.

So a good, and probably necessary thing, is to eventually buy a hard drive that will be your dedicated music vault. And soon after, get a second for backup. You can at least get started using your internal drive, and then export your library when you get an external drive. You'll find quality 500GB and 1TB drives in the $150 range, and that should be enough for most music listeners. a 1TB hard drive can hold around 2500 - 3000 hours of CD-quality lossless-compression files or 1500 hours of lossless files.

The mistake most people have already made is they have ripped their CD collection into the computer as mp3's or AAC's. And sadly, many people get rid of their CD's after doing this. Most didn't realize that importing the music would degrade the sound, because the default setting in iTunes is for AAC, just like the default in Media Player is for mp3. At least since iTunes+ was launched in 2009, the default has been for 256kbps, which was an improvement in sound quality. Prior to that, defaults were set for the God-awful 128kbps bit rate. Your library will eventually contain a mix of lossy-compression, lossless compression and possibly lossless audio files. iTunes can play between all of these, even in the same playlist, with no problem.

It's important to understand that at least for now the music you download from iTunes, Amazon etc. will still be mp3's and AAC's; the changes we made in import settings only affect CD's you are ripping in, and files you are changing from one format to another. What a lot of people don't know is that many artists already offer CD-quality 44.1/16, and even better, downloads on the band's personal site for quality-conscious fans. They may cost 10 cents more than the mp3, but it is so worth it. Also, in February 2011 Apple began talks with major labels for iTunes to be able to offer the full-quality download option. This is what we have been waiting for!!!

To see what format songs in your existing library are, select a song and get info. On the summary page you'll see kind, size and bit rate. More efficiently, looking at list view, control-click or right-click on a column header, 'Name' for instance, and you'll find Kind and Bit Rate that you can add as columns. That way as you get into ripping CD's back into your library correctly, you can sort to see what hasn't been upgraded yet. Note that in the info window it refers to resolution (number of bits) as Sample Size. 

As you explore high resolution downloads, you will find 44.1k and 48k in both 16 bit and 24 bit resolution. But once you get to 88.2k and above, they will always be 24 bit. We'll get into that in just a bit.

STEP 3 - DEALING WITH THE IPOD/IPHONE

Many aren't aware that iPhones and iPods can play AIFF or WAV files at 44.1/16 and 48/16, and Apple Lossless files at those two sample rates and either 16 or 24 bit. In playlists or shuffle mode, like iTunes they'll go happily between mp3's, AAC's and Apple Lossless/WAV/AIFF. Some mp3 players can as well, but you'll have to check the specs of your player. Yes, this means you can only get 24 hours of CD-quality Apple Lossless files on your 8GB iPod Nano. So if that's a problem, and you don't really care about getting better sound from your iPod, there's two solutions.

First, connect your iPhone/iPod and select it in iTunes. At the bottom of the summary page is a checkbox labeled 'Convert higher bit rate songs to 128kbps AAC'. When this is checked, your lossless or lossless-compression audio files will be converted to the smaller AAC's as they load into your iPod, but the original files on the computer will remain untouched. It will take a bit longer than usual, but after you get your main choices loaded you are usually only changing an album or so at a time. [edit 7/5/12] - GOOD NEWS ON THIS SUBJECT. GO TO iPhone/iPad Import News. 

If you are using standard issue earbuds, or just above, you will probably not hear the difference between these 128kbps and the iTunes+ 256kbps AAC's. You could hear it if you were listening over your good system, but the point is you will now have full CD quality files for that. However, if you have invested in high quality earbuds, and you've done the test and can hear the difference between 128kbps and 256kbps on them, then your only option is to create a whole new library of stuff you want on your iPod as 256kbps AAC's. Yes, this is a whipping and takes up even more space, but once you hear your digital music sounding even better on your hi-fi system than you remember the CD's sounding it'll be worth it. Also, if your earbuds are that good, and you've got anything 8GB or above in iPod space, you're probably going to want to go with the full quality Apple Lossless or AIFF files anyway. If you do create a separate AAC library for iPod use, it is MUCH faster to create them from the full quality files you've already imported rather than using the CD's, and there'll be no difference in quality.

STEP 4 - HIGH-DEFINITION, OR HIGH-RESOLUTION DIGITAL AUDO

Most music lovers will be totally satisfied with 44.1/16 CD-quality digital audio. But for those interested in true audiophile quality sound, 24 bit digital at 48k and higher sample rates is the answer. So the obvious question is, where can I get music in these better sounding formats? Besides artists offering CD-quality and better downloads on their personal sites, you will find a growing number of sites that sell music in high-definiton formats. For instance HD Tracks has an amazing selection of music available in 44.1/16 and up to 192/24 in either AIFF or FLAC files. If you don't think the second Rolling Stones album could possibly sound any better at 88.2/24 bit than it does on CD, or even mp3, you're very wrong. Though their selection is tiny compared to iTunes I would always check both, because the same album on hdtracks at 44.1/16 is almost always the same price or cheaper than the iTunes Store's inferior AAC.

Normally 88.2k and above, 24 bit audio is only available from these sites as FLAC files so they don't take so long to download. But you can download a free utility for the Mac called XLD (X-Lossless Decoder) that will convert the FLAC files to Apple Lossless, AIFF or WAV without degrading the quality, or to the best sounding mp3's or AAC's possible. And as I pointed out earlier, iTunes should support FLAC files soon anyway.

Realistically, 96k is the highest sample rate that even the most serious audiophile will probably be interested in, and 88.2/24 is ideal in my opinion. In blindfold tests listeners were not able to identify 88.2k vs. 176.4 or 192k with any consistency. Part 2 will have some VERY important information regarding playing any sample rate above 44.1k in iTunes.


*** UPDATE 1/3/12  *** It seems that a big push is happening to make 96/24 the standard for consumer hi-definition audio. As I stated above, it should be 88.2k in my opinion, and there are technical=quality reasons for that regarding production and mastering in hi-resolution and then downsampling for CD and downloads. But some mastering rooms, like DES for example, have the gear and know the secret for eliminating any difference in quality. So keep and eye on audio production news and forums, but production at 96k/24 bit would seem to be the future. 

So get busy starting the arduous task of getting your best CD's properly imported into iTunes. You may just want to leave what you've already imported as mp3's or AAC's alone for use with your iPod and start a whole new library for the high-quality files. Click Here for info on how to create separate libraries. Now that you know what files sound the best, Part 2 will cover how to get the best sound quality from iTunes itself when it plays these files. There are sneaky little settings that will degrade the sound.

A MISCONCEPTION:

The Import Setting in iTunes determines what kind of files your CD is ripped as, and it can also be used to change one audio file type to another. So a lot of people are under the misconception that they can take lossy-compression files they've already created, and covert those to a lossless file. Yes, you can do that, but it will not sound like a lossless file that you ripped straight from the CD. If fact, it will likely sound worse than the lossy-compression file you started with, it will just take up five times the disc space. You can change one lossless format to another, AIFF to WAV for example, without losing quality. You can go from lossless to lossless-compression files, and back, without losing quality. And you can go from lossless or lossless-compression to lossy-compression files, which will reduce quality. But converting lossy-compression to a lossless file does not 'get back quality'.

FOR THE HIGH-TECH CROWD:

If you want the best possible quality, the XLD (X Lossless Decoder) utility I mentioned is considered to be the best CD ripper and audio file convertor made. Its proprietary method of absolutely accurate CD ripping is called 'CDParanoia', and that kinda sums it up. Plus, besides WAV and AIFF it can create Apple Lossless, FLAC, AAC, mp3 and others in the best possible quality. Just search XLD for the free download.