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.

10 COMMON MIXING MISTAKES THAT CAN RUIN YOUR PROJECT

From having dealt with literally tens of thousands of mixes, here are 10 mistakes that I see people make over and over again. These are mistakes that will prevent your final mastered tracks from having the clarity, sparkle, punch and volume that you want, and they're fairly easy to address. These are general common-sense guidelines, but it's always important to remember the #1 rule of recording - There are no rules.

1.) THE MIX IS TOO LOUD - This is the most common mistake engineers make today. The mixes you submit for mastering should not be done with eq's, compressors and limiters across the stereo buss. If a stereo buss compressor gives a particular flavor to your mix that you can't get any other way, then by all means use it. But don't do it for the purpose of making the mix louder. If the mix is over-compressed and limited, that cannot be undone. And it totally ties the hands of the mastering engineer. What do you think will sound better? Letting the mastering engineer compress the mix with his $10,000.00+ analog mastering compressor, or letting the mix engineer do it with his $100.00 plug-in? You should also leave headroom, which means your peaks should not be hitting full scale digital 0 (0dBfs). Looking at your stereo peak meters; the hottest peaks in your mix should not exceed -3dBfs, and if you're doing a proper 24 bit mix, -6dBfs is ideal.

2.) THE MIX IS TOO DYNAMIC - Everyone wants their mastered tracks to be huge and loud. But that can't all be done in mastering. As I said in point #1, you generally should not compress or limit the stereo mix. But you should control the dynamics of individual tracks and groups. That doesn't mean squash them, it means control them. Assign your drums to a stereo group and put a stereo compressor/limiter across that group. Usually a compression ratio around 2:1 showing a gain change of around -3dB will do wonders for tightening up the drums, increasing tom & kick sustain and emphasizing the ambience of the drum sound. Adjusting attack and release is critical, as too fast of an attack will kill the punch. You might also want to put limiters on the kick and snare tracks alone if they are too peaky. When you hear a song that is just huge, loud and opened, you can be sure a lot of care was taken in eq'ing, compressing and limiting the individual tracks.

3.) TRACKING AND MIXING AT LOW SAMPLE RATES AND/OR BIT DEPTH - In these days when hard drives are so inexpensive, why would anyone track at 44.1k, and even worse at 16 bit resolution? Even 48k sounds better, but if you want your mix to come alive, you should be tracking and mixing at 88.2k or 96k, 24 bit. If your music is going to be released as an audio CD, 44.1k/16 bit .wav or .aif downloads, or even mp3's or AAC's, the ideal sample rate for tracking and mixing is 88.2k. This allows the mastering engineer to do a linear decimation to 44.1k after mastering, meaning the sample rate converter has to simply divide by 2, which results in the best sound. ESPECIALLY if you are using a real mastering room that will be using analog processing, the difference between a 44.1k mix and an 88.2k mix is night and day.

4.) CRASH CYMBALS TOO LOUD - Want a big, powerful drum sound? Get those crash cymbals down! Loud crash cymbals will completely diminish the apparent size of the drums, and consequently the entire mix. And they will totally cloud and blur the rest of the top end of the mix. It's fine if you want a crash to punch through a couple of times during the mix to emphasize transitions etc., but the entire mix should not be awash in crash cymbals. Solo your drum mix; the crash cymbals should be lower in volume than the snare.

5.) TOO MUCH 'POINT' ON THE KICK DRUM - The 'point' is the slap or click at the leading edge of the kick drum. It adds apparent punch to the kick, but too much can totally destroy an otherwise good mix. You may think it's just a narrow sliver of frequencies that could easily be pulled back in mastering, but in reality it is very broad-band and sits right in the sweet spot of critical upper-mid frequencies where vocals, guitars, strings, synths etc. need presence, and they will all suffer if it has to be pulled back. In the case of the kick drum's point, as in so many things in recording, less is more.

6.) KICK DRUM, SNARE AND TOMS ARE NEGATIVE POLARITY - This is related to phase, but different than being out-of-phase. This means the leading edge of the signal falls rather than rises, which will cause the speaker to pull rather than push at the attack of the drum. That doesn't happen in nature, and it will diminish the punch of the kick and bigger toms. Look at the wave forms of your drum tracks. If the waveform at the beginning of a note goes down before it goes up, it is negative polarity. It's a simple matter on any DAW to highlight the offending track and select "Reverse Polarity". Then you'll see the leading edge rise, as it should. Surprisingly, many professional drum samples are negative polarity.

7.) TOO MUCH SUB-BASS - Almost all home and car systems have subwoofers these day, so it is more important than ever that the sub-bass be correct. But with the home-recording revolution comes the fact that a lot of mixes are being done on small speakers that can't reproduce sub-bass, or on big speakers/subwoofers in a bad control room that can't reproduce the sub-bass properly, or the worst, on headphones. I regularly see mixes from home studios where the bottom end below 40Hz. needs to be pulled back as much as -10dB! Yes, the mastering engineer can do this, but usually not without the rest of the mix suffering. The proper way to address bottom end is by properly eq'ing the individual bass elements of the mix, not by eq'ing the entire mix. An easy answer is an RTA (real-time analyzer) plug-in, which will show you a graphic representation of the tonal balance of your mix. For the majority of rock and pop mixes, the meat of the kick drum is around 40 - 50Hz. You should not see a rise in energy below those frequencies. For hip-hop and r&b, sub-bass below 40Hz. is important, but it should not be out of control. Look at professional mixes on your RTA and see what their tonal balance looks like. As I said in point #2, eq'ing, compressing and limiting the kick drum and bass independently is key to having a huge bottom end without sacrificing the volume the entire mix can eventually be.

8.) VOCAL SIBILANCE WAS NOT ADDRESSED PROPERLY - Sibilance (the sharp ear-piercing 'ess' sound in vocals) should really be addressed during the tracking process. If the tracking engineer let it slip, the second best alternative is to control it during the mix. The worst alternative is to fix it in mastering, which means the entire mix has to be de-essed, and that is going to affect everything else in the 7k - 8kHz. range. If you're working with a vocalist with a lot of sibilance, the best technique is to de-ess some while tracking the vocal, along with mic selection and placement, and then de-ess a bit more during the mix. The results will be much more transparent by preventing one de-esser from having to over-work.

9.) BEING TOO RUSHED - This is a huge one. There is really no reason why you should be rushing the mixing and mastering stages of production. People who have gone through the music production process more than once usually don't schedule release parties, radio promos etc. until they have CD's in-hand. Somehow the music universe has survived without hearing your album for centuries now, it can surely get by an extra couple of weeks. You should allow yourself several days to live with your mastered project before you send it to press. And you shouldn't just rush back to the studio with it. The important thing is how it sounds in your car, on your stereo system, on your friend's stereo system, from the next room, in a retail store if you have a friend working there that can sneak it in - all the ways you normally hear music.

10.) EXPECTING MASTERING TO MAKE YOUR MIXES SOUND PROFESSIONAL - Despite what many mastering engineers will tell you, quality cannot be created in the mastering room. All the mastering engineer can do is enhance the quality that is in your mix, and to make sure nothing is getting in the way of the critical elements of each mix. He cannot 'pull a diamond out of a goat's butt'. The key to having a big, professional sounding product to release is taking your time and paying close attention to each little detail, from the time the first mic is set up to the final tweaking of the vocal during the mix. If all is done properly, the mastering engineer will then be sweetening your mixes, which is what mastering should be all about, and not trying to repair them.

10b.) ALLOWING THE MIX ENGINEER TO 'MASTER' - Yes, anyone can afford a 'mastering' plug-in bundle these days. But unfortunately the plug-ins do not come with the decades of experience that a real mastering engineer will have. And they do not include the room and speakers that are necessary to hear what is really going on. Do not allow your mix engineer's ego, or greed, to get in the way of the quality of your final product. The real heavyweights in the industry know that mixing and mastering are two completely different jobs. The biggest names in mix engineers have no problem with a different engineer being credited for mastering. They know that what is in their best interest is to be credited as the mix engineer on a great sounding album, not being credited for every job on a mediocre sounding album. Whether you use DES Mastering or not, let a professional mastering room master your project.

SOME ALARMING NEWS REGARDING STORAGE OF YOUR MUSIC

Most young artists and producers, and many veteran ones, don't give enough consideration to archiving their music. (Archiving means to securely store important information for a long period of time.) It is wise to archive your stereo masters in both mastered and unmastered form, if not your complete sessions and tracks. Now it turns out that people who think they have their music safely stored are discovering it is gone.

Since their inception, countless artists, producers and labels who endeavor to keep their music properly archived have used the CD-R and DVD-R for storage. This is a seemingly obvious choice because it is not mechanical like a hard drive so it can't fail if properly stored. For the past 20 or so years since CD plants have accepted audio CD-Rs as masters, many mastering rooms have offered an archival service, storing Production Master CD's on a yearly contract.

Mastering rooms are now beginning to report that CD-R's they are pulling from storage vaults where they have sat since they were created are no longer readable. Not only had these discs never been exposed to light, they'd been stored in perfect temperature and humidity. In some cases these have been masters from major labels. It appears that somewhere in the range of 10 to 11 plus years is when the dye in the data layer or recordable discs begins deteriorating, even if the disc has never been exposed to sunlight. As of yet there is no report of anyone being able to recover a deteriorated disc in any way. You may have older discs yourself that work fine, but my thought is it's not worth it to trust them any longer.

The answer to this is "migration", which in the world of archiving means to transfer all of your data from one medium to another on a regular basis. What is now recommended is to migrate your music archive every five years to new discs, drives or whatever future media becomes available. You should store your material on both hard (or solid state) drives as well as a hard medium like CD-R or DVD-R. DO NOT DEPEND ON A HARD DRIVE ALONE!

This will also keep you on top of technology, as you can be sure that the ability to read CD-R, DVD-R, firewire, USB or whatever will be obsoleted as soon as the manufacturers can sneak it in on us.

I would also recommend our blog post Don't Forget the Future for information on what you should get from your mastering room for proper archiving.

Since I've already received comments on this, let me explain - this does not mean your CD collection will become unplayable. A CD-R is not a CD. The data layer of a CD is a metal layer that has physical pits, called 'picts', that the playback laser reflects off of. The only thing that would prevent the laser from seeing the picts is if the surface of the CD is scratched. The data layer of a CD-R is a photo-sensitive dye on which the CD burner creates a a series of black dots, if you will, that simulate the physical picts on a CD. It is this dye that is deteriorating where the 'dots' are no longer visible to the player. The same is true of DVD vs. DVD-R.

One more side note - this is another reason why, when you go to manufacturing, you need to verify that you are getting a replication of CD's, not a duplication onto CD-R's. Unless you're not interested in your music being playable after 10 years or so.

A NEW PROBLEM REGARDING CD MASTERS

If you are producing a CD, this is very important information concerning the production master that you deliver to your manufacturer.

All CD plants can accept a Red Book Standard CD-R as a production master. The problem with music on CD-R has always been that it contains an enormous amount of errors. When CD plants first began accepting CD-Rs it was very difficult to cut a CD-R that would meet the CD plant's standards. That is when Sonic Solutions became the standard in mastering software, because a CD-R master burned on a Sonic Solutions system (called a 'PMCD') was absolutely as low error rate as possible.. These PMCDs were burned on a specific Sony writer at 1x speed.

Unfortunately, rather than maintaining a high standard, the CD plants lowered their standards to the point where you have to deliver an almost unplayable CD-R for it to be rejected by a plant. This is not good news, as the CD's made from high-error CD-R masters will be more unreliable for playing on car players, boom boxes etc. and will have a lower sound quality. Consequently Sonic has maintained their status as the best mastering software, as a 'native-burn' Sonic PMCD is still the lowest error Red Book Standard audio CD-R. But now we have a new problem.

It is still important that audio CD-Rs to be used as production masters be cut at lower speeds. For instance the current Sonic soundBlade mastering system as used as DES cuts at 4x speed. However, CD-R manufacturers are continually modifying their dyes to be optimized for the fastest CD burner speeds. The result of this is that the last manufacturer who made CD-Rs for lower speed burns, Taiyo Yuden, has now scaled down that facility and has discontinued those discs. Mastering rooms who have already tried the new Taiyos report having to burn 5 or more masters before getting one with acceptable error rates. Even burning at 8x results in unacceptable errors. And it has been proven that anything approaching 10x speed definitely reduces the sound quality.

But fortunately there is a solution. The DDPi, as described in our blog entry DDPi - The New Preferred Master for CD Replication, is a completely error-free master. Even though in most cases it is delivered to the CD plant on a data CD-R or DVD-R, this does not affect the quality of the DDPi. The reason is, the method in which data is written to a CD-R is completely different from the method used to burn an audio CD-R. As we said, even the best audio CD-R has a lot of errors. But data CD-Rs are written in such a way that any bad sectors on the CD-R are skipped, and after the data is written a checksum is performed, which verifies that what was written to the CD-R or DVD-R is bit-accurate to the files it came from.

So once again we are emphasizing the importance of DDPi as a production master. DES will provide our clients with info on the best CD plants to use, as not all can accept DDPi.

Again for more info on the DDPi read our entry DDPi - The New Preferred Master for CD Replication.

DDPi - The New Preferred Master for CD Replication

The DDPi (Disc Description Protocol image) is now acknowledged as the superior production master for any optical disc medium - CD, DVD or Blu Ray. The DDPi is an absolutely error-free master, which creates a superior sounding CD in the case of audio, and also creates CDs that are more reliably played by cheap CD players, boom boxes, car players etc.
Originally just DDP, it has actually been around for more than a decade, and has been the standard in video for that long. It also has been in use in audio CD mastering and replication, but on a much smaller scale. The DDP breaks the audio, subcodes, TOC and metadata down into separate elements; five or six files total in the file set. It was originally delivered on an 8mm video cartridge created by a machine called an Exabyte. The downside was it required a specific, costly machine at both the mastering room and the CD plant. And it was a mechanical tape cartridge, which can fail. So enter the future, and for some, the present: DDPi. DDPi contains all of the elements of a DDP Exabyte tape, but it is written directly to a hard drive in the mastering room and can then be delivered to the CD plant on a data CD-R or DVD or if available it can be uploaded directly to a CD plant's server. For your reference, DES will upload the DDPi along with our DDPi player which will allow you to listen to the master, check CD-TEXT and ISRC's, and burn your own CD. A huge advantage to this is that you will be using the exact DDPi that we will be sending to the plant.
The only downside, if you want to call it that, is that you have to use a cutting edge mastering room that understands and can create a DDPi file set, like DES Mastering (www.desmastering.com) for instance, and you have to use a CD manufacturer that can utilize the technology, which coincidentally DES can steer you to.

Stem Mixing

Mixing to stems has been common practice in sound for film and video for decades, but it is relatively new to the world of music production. Many people still don't comprehend that the mastering engineer cannot separate elements in a stereo mix and effect just that one element. For instance if he wants to brighten up the vocals in a stereo mix, everything else in the same frequency range will be brightened also. But if the mastering engineer has stems to work with he has a lot more flexibility and the result can be a much better finished product.

Stems are stereo (or mono) subgroupings of instruments or vocals. For example, the most common stem mixes have a stereo instrumental stem and a stereo vocal stem. When these two stems are set to unity gain (no volume boost or cut) and played through a common stereo output, you should have the complete stereo mix as the mixing engineer/producer intended it. But now if the mastering engineer needs to brighten up the vocals for instance, or thinks the guitars have too much midrange, then he can work with one stem without affecting the other. You might also have a case where the bass has been separated out to a mono stem of its own, so the mastering engineer can compress or eq it independently of everything else.

Stem mixing is really very simple. You don't do anything different until you're ready to bounce your mix. Mix as you normally would, get all of the instruments and vocals balanced, eq'd, panned and f/x'd until you're happy with the mix. Then mute all of the vocals and bounce your mix. You now have the instrumental stem. Then, unmute the vocals, mute everything else, and bounce again. You now have the vocal stem. If you load the two stems back in, set them for exactly the same start time, and play them both through the stereo output, voila! You are hearing your stereo mix just as you wanted. If you have done things correctly, listen to the instrumental stem and you will hear that all of your automated fader moves, f/x etc. have been printed with that stem. You should hear no vocals, vocal reverb, echo or anything else related to the vocals. Likewise if you listen to the vocal stem there should be no hint of instruments or instrument f/x.

So you see it would be the exact same procedure if you wanted to separate out bass, background vocals, drums, whatever. You just mute everything else in the mix except those elements and print. But the mastering engineer would prefer you keep it as simple as possible, the ideal being an instrumental stem and a vocal stem as in the example above. Don't distract the mastering engineer by delivering too many stems in one song so that he is suddenly having to listen like a mix engineer and not a mastering engineer (two VERY different ways of listening, btw).

If you are mixing through an analog console with analog f/x, you need to be very conscious of processor noise. When you are printing your vocal stem, you should mute all f/x processors that are dedicated to instruments only, or if you have dedicated returns for instrument f/x then those should be muted. Otherwise you will be printing the noise from your instrument f/x processors onto the vocal stem, and then you will get the noise again when you print the instrumental stem. Although it may seem like a minor detail, you should do the same when you print the instrumental stem regarding the vocal f/x returns. Even on loud tracks, every little bit of noise you can eliminate will make a difference in the final product.

In the hip-hop world, delivering stems for a single can make your life much easier. All you need to deliver is the instrumental and vocal stem for each song. Now the mastering engineer can add the two together for the club version, mute the bad words on the vocal stem for the radio version, instrumental stem only for instrumental version, vocal stem only for acapella version. Too easy. (Or save a little money and do a clean vocal stem yourself if there are a lot of words that need to be muted).

Make sure you talk to your mastering engineer before you deliver stems. Not all mastering rooms are as technically hip and savvy as DES Mastering (shameless plug), so you shouldn't assume that they can work with stems.

Master, Master, Who's Got the Master?

There's a lot of confusion concerning what a 'master' is. One problem is, too many things are called masters. If you have a 'master', hopefully it will be labeled with one of the following terms. Or if you are in production, and you want to do yourself, your client and anyone else down the production chain a huge favor, learn and use these terms. For these purposes we'll talk about stereo only. Surround opens a whole different can of worms. Here we go!

MULTITRACK MASTER, TRACK MASTER

This is the master containing the unmixed tracks from the recording session. They range from 2 to 32 tracks in analog tape formats, up to 48 tracks in digital tape formats, and 128 tracks and beyond on computer-based systems. On modern track masters, each instrument and voice is still on a separate track. On track masters from around 1967/68 and before, you would have two, three or four tracks of combined or compiled (comp'd) recordings. Say if you had the final 4-track master from Sgt. Pepper, on those four tracks you might have all of the Beatle's rhythm section on one track, the London philharmonic on a second, a percussion section on a third, and all of the Beatles vocals on the fourth. Regardless of the number of tracks, these masters have to be mixed to stereo (or mono) before you proceed to mastering and manufacturing. They can be analog or digital reel-to-reel tapes of varying sizes, audio cassettes, VHS or Hi-8 video cartridges, and these days thumb, USB or Firewire drives, data CD-Rs or DVDs.

STEM MASTER

Mixing audio in stems has been commonplace in the film and video industry for decades, and is becoming increasingly popular in music production. Stems are stereo or mono subgroup mixes that are then combined for the complete stereo mix. In music for instance you could mix a stereo vocal stem, a stereo instrumental stem minus bass, and a mono bass stem. This would allow the producer to easily create a vocal up version for radio, edit the vocal for a clean version, pump up the bass for a club version etc. In mastering, stems allow the engineer to process and control the individual stems rather than having to process the entire mix. Stem masters could be any of the same formats as the track masters above.

MIX MASTER, MIXES, MIX FILES, BOUNCES, BOUNCE FILES, SOURCE MASTER (in mastering terminology)

These contain the stereo mixes that have not been edited or mastered. These can be various sizes of analog or digital reel-to-reel, analog cassette tape, VHS, Beta or Hi-8 video tape, DAT tapes, audio CD-Rs, or folders containing audio files on data CD-R, DVD or any form of hard drive.

For people who record and mix 'in the box': Do not be a lazy engineer. Your individual tracks in your session folder should have proper file names, "Kick", "Snare" etc., not "Track 1", "Track 2"... Your mixes should be in one folder labeled as "Mix Masters" etc.

EDIT MASTER, BANDED MASTER, SEQUENCE MASTER, SEQ MASTER

In the analog days of vinyl, this referred to an analog mix master tape that has been sequenced and topped & tailed (noise before and after each song edited out), timed leader tape has been inserted between tracks for proper spacing, and leader tape has been added to the head and tail of the reel. It also implies that any inner-song editing has been done. In the analog days we would say these tapes have been 'prepped', meaning the tape has been prepared for the cutting room. Unless otherwise noted, this master has not had any further processing such as eq, compression or limiting, which was done at the lathe as the lacquer was cut. In today's world, mastering engineers prefer that you do not top or tail your mixes, leave a second or two of noise before and after the audio.

In the digital age, a BANDED MASTER has a new meaning. Many artists want to have some or all songs on their album crossfade between each other, have no space between tracks etc. But of course this can cause problems in the age of downloads since the ending of a song that crossfades into another song will just suddenly chop off if you download the first song only. Or if you download the second song, you hear the end of the first song fading out as the song you wanted starts. So many artists have their mastering engineer create a 'banded master' which has a basic 2 seconds or so of silence between songs. They will use this as the source for online content so the songs have clean in's and out's. This also allows them to suggest purchasing the CD if the listener wants to hear the album the way it was really intended. Unlike the analog version, this type of banded master would be implied to have all mastering processing applied. These banded masters can be on any of the media described in the next category.

PRODUCTION MASTER, PRE-MASTER, EQ MASTER, EQ AND LIMITED MASTER, PMCD, REFERENCE MASTER, GOLD DISC MASTER, DDP, DDPi

A master that has any of these labels would be assumed to have all mixing, editing, sequencing and masteering applied and is ready for manufacturing as is. Some of these need further explanation:

PRODUCTION MASTER, PRE-MASTER, EQ MASTER, EQ AND LIMITED MASTER - The standard media that manufacturers can or could accept that would have one of these labels would be analog or digital reel-to-reel tape of varying sizes, VHS, Beta, Hi-8, and 3/4" U-Matic video tape, audio cassette tape, DAT tape, red-book standard audio CD-R, and now some manufacturers will accept production master audio files on data CD-R, DVD, any type of hard drive or as uploads to a server. 'EQ Master' and 'EQ and Limited Master' are old-school terms for labeling production master reel-to-reels that were prepped for the cutting room. If your mastering guy uses one of these terms you can be pretty sure he's been around the block.

PMCD, REFERENCE MASTER, GOLD DISC MASTER - These would only apply to a CD-R. The definition of PMCD has changed. Originally, this meant 'Pre-Master CD'. This was a revolution in CD manufacturing that was developed by Sonic Solutions and allowed CD plants to cut glass (explained below) directly from a CD-R, eliminating a very expensive step that will be explained later. The Pre-Master CD was a CD-R that could only be created on Sonic Solutions mastering systems and contained a data burst that fed the TOC (table of contents) timecode information into the glass mastering program independent of the audio. Probably no, or at least very few, CD plants can use Pre-Master CDs any longer, as the CD burners that Sonic needed to create them have been obsolete for about 15 years. And now CD plants can cut glass from ordinary red-book standard audio CD-Rs. These audio CD-R production masters were originally referred to as a Reference Master or a Gold Disc Master (even though the disc may be silver or green). Some still use those terms, but increasingly they are referred to as a PMCD, now meaning 'Production Master CD'. A CD-R with one of these labels would normally be for CD replication, but often production masters for vinyl records or in the days of cassettes would have the same label. If you have a master that is labeled 'PMCD', there is really no way of telling which type it is if you don't have a Sonic Solutions system with the proper CD drive. But never fear, a Pre-Master CD will play on a normal player, and can be used by a CD plant, just like a current Production Master CD.

DDP - The DDP (Disc Description Protocol) is acknowledged as the superior production master for any optical disc medium - CD, DVD or Blu Ray. The DDP is an absolutely error-free master, which creates a superior sounding CD in the case of audio, and also creates CDs that are more reliably played by cheap CD players, boom boxes, car players etc. The DDP breaks the audio, subcodes, TOC and metadata down into separate elements, and is delivered on an 8mm video cassette created by a machine called an Exabyte. The downside is that it is still a mechanical tape cartridge, which can fail, and it requires a specific, costly machine at both the mastering room and the CD plant. So enter the future, and for some, the present:

DDPi - DDPi is a 'Disc Description Protocol image'. and is the new standard in production masters for any optical disc, including audio CDs. It contains all of the elements on a DDP Exabyte tape, but it is written directly to a hard drive in the mastering room and can then be delivered to the CD plant on a data CD-R or DVD or it can be uploaded directly to a CD plant's server. The only downside, if you want to call it that, is that you have to use a cutting edge mastering room that understands and can create a DDPi file set, like DES Mastering (www.desmastering.com) for instance, and you have to use a CD manufacturer that can utilize the technology, which coincidentally DES can steer you to.

The reason Sonic Solutions (now SonicStudio) workstations, as used by DES, have been the mastering industry's standard for 20+ years is not only because of their superior sound quality but because Sonic writes the absolutely lowest error PMCD compared to any other system. However, you would probably be shocked to see how many errors even these comparatively low-error masters have, and these translate directly to your manufactured CDs. The thing is, a CD player has a certain amount of DSP (digital signal processing) allocated for error correction. The amount of DSP being performed will directly affect the sound quality of the playback. So the fewer errors on the CD, the better the sound. That is why real mastering rooms use very specific software and burners. If the person doing your mastering is using standard off-the-shelf CD burners and software, you are losing sound quality. So to emphasize the advantage of DDPi, it is an error-locked system, meaning it is either 100% accurate or 100% fail. If it works, it is absolutely error-free, yielding the best sounding CDs possible. But rest assured that even if you are already using a plant that can only accept Production Master CDs, DES Mastering can provide you with the best quality master possible. OK, enough commercials; onward, through the fog!

Now things get a little tricky, because we have a difference in terminology between Europe and the U.S. In the U.S., what we do at DES (eq, compression, limiting, song sequencing, spacing etc.) is called 'mastering'. In Europe, this is called 'pre-mastering', and 'mastering' means that you are creating a part that will be used in manufacturing; cutting lacquer for vinyl, cutting glass for CD replication (we'll get to that) etc., and this is also called mastering in the U.S., which causes some confusion.

PCM-1610, PCM-1630

Before Sonic created the Pre-Master CD, anything going to CD replication had to be on either a Sony PCM-1610 or PCM-1630 formatted tape. Simply put, these were like gigantic DAT machines with a couple of extra analog data tracks where timecode and pq subcode info was put. The converter itself was probably 30"wx24"hx30"d and weighed 100 lbs. or so. Rather than a tiny DAT tape the digital audio was recorded onto a professional 3/4" U-Matic video tape, which required an enormous video deck. If I remember correctly, the cost of the converter with the video deck was around $25-$30,000.00. Of course smaller mastering rooms couldn't afford this, so some CD plants would allow Production Master DATs that they would then format to their 1630, for an extra fee of course. If the only master you have is one of these U-Matic tapes, there are still mastering rooms that have a 1630 system and can get your material onto a more usable format, but you would be advised to do this asap. If you need this contact us at george@desmastering.com and we will refer you to the proper people.

GLASS MASTER

Boy, does this cause a lot of confusion. With only the rarest of exceptions, glass mastering is only done at your CD plant. A few of the super high-end (and priced) mastering facilities may cut glass, but they are few. Even a lot of people who consider themselves mastering engineers get it wrong and will call the PMCD (or Reference Master or Gold Disc Master, as you now know) they create a Glass Master. Getting back to the terminology thing; the CD plant uses the European terminology - the processing and assembly done by DES for instance to create a PMCD or DDPi would be 'pre-mastering', cutting the glass at the plant from this would be the 'mastering'. This causes confusion when a plant says that mastering is included in their pricing. What they are talking about is cutting the glass master. Their price does not included pre-mastering.

The glass master is a large glass disc approx. 240mm in diameter that is painted with photo-resist. Then the digital audio from the PMCD, DDP, DDPi or PCM-1610/1630 is photo etched onto this using an LBR (Laser Beam Recorder). Stampers are then created from this and the photo-resist is peeled off the glass which is then highly polished to be used again. So the CD plant will only have a limited number of glass discs that are used over and over. This is the CD equivalent of cutting lacquer for vinyl records.

A note about production masters for download-only releases:

At the very least, this should be a PMCD. Online stores such as iTunes and CD Baby will not allow you to upload your own mp3s or AACs. They want the full resolution, CD-quality audio files. That way, not only can they create the best quality compressed files with their own CODECs, but as technology improves, like when iTunes went to iTunes+, they can create a new set of compressed files from your full-resolution upload. Hopefully, as connection speeds increase and storage gets cheaper, we will be downloading full CD-quality music, or even better.

As we've said before, you should NEVER accept an mp3, AAC or any other data compressed file as a mix master or production master. See our entry "Audio Production in the Age of mp3 and AAC" http://desmastering.blogspot.com/2009/09/audio-production-in-age-of-mp3-and-aac.html.

I intended to include a list here covering a question that we mastering guys hear all of time time; "I've found this (fill in the blank) type of tape/disc from an old session. What could this be?", but this has already gone longer than I expected. I'll do that next entry.