As I said in my post on understanding the future indie music market, you need to know the minds of your listeners. If you target teenagers, but you’re a few years off yourself, this article could prove enlightening: High School Round Table: A world of music.

Miguel: I think music is a huge influence. That song “Grills” came out. Ten minutes later, everybody had a grill.
Hilary: If you listen to country, you are going to have jeans and a cowboy hat. If you listen to rap, you are going to dress like the girls on the videos.

Bob Katz originally wrote The Secrets of Mastering for TC Electronics, and buyers of their Finalizer hardware, but his thoughts aren’t specific to the unit.

Mastering is the art of compromise; knowing what’s possible and impossible, and making decisions about what’s most important in the music. When you work on the bass drum, you’ll affect the bass for sure, sometimes for the better, sometimes worse.

He covers, in more detail than you’d expect from a free article, all the main aspects of mastering: Monitoring, metering, equalization, dynamics, and preparing for radio. I’ve read the paper half a dozen times, and I still learn something from it each time.

Keep your mixes balanced and not too bright or too bassy. Shoot for soft highs and tight basses. Don’t try to get the CD-Quality sound at the mixing studio. Let professional mastering do the rest.

Tip #10, in particular, is a favorite of mine: Hire a mastering engineer to critique your mixes before you send them to be mastered:

Most artists understand that if you involve a great producer in your songwriting you may benefit from his/her input in terms of song structure, melody or lyrics. But they don’t understand that involving a mastering engineer in the mix may have a similar positive effect on the mix… When you get the initial mixes ready, run them by an experienced mastering engineer and ask for his/her input. In most cases it only takes one to two hours to go into details over every song on a CD. So you are looking at $75-150 for this service, but it can save you a ton of grief and money later on.

(Note: It’s a 4-part article. Here are part 2, part 3, and part 4.)

Then Mr. Cooder noticed something else: When he burned a copy of the album using Apple’s iTunes software, it sounded fine. He didn’t know why until one of his younger engineers told him that the default settings on iTunes apply a “sound enhancer.” (It’s in the preferences menu, under “playback.”) Usually, that feature sweetens the sound of digital music files, but Mr. Cooder so liked its effect on his studio recordings that he used it to master — that is, make the final sound mixes — his album.

As the article states, Cooder is likely the first well-known artist to master an album through iTunes. But the effect of iTunes’ sound enhancer is obvious to anyone who hears it. So does the software do anything that might qualify as mastering? Here’s a collection of thoughts on how iTunes ‘sound enhancer’ functions:

What iTunes does in this respect is the same as the ‘Wide’ button found on ghetto blasters in days of yore – some high frequencies from each channel are phase-inverted and fed to the opposite channel. This makes the stereo-width apparently greater – but comes at the expense of any real definition of placement.

(And for the record, I’m not endorsing the use of iTunes software in place of a trained mastering engineer. Your music should mean more to you than that.)

One of the reasons people take their music to professional mastering engineers is that they bring a ‘fresh pair of ears’ to a project. If you’ve been even partly responsible for writing, arranging, recording and mixing your material, your judgement mat be coloured by over-familiarity with its contents. So have somebody sit in on the mastering session who’s never heard a beat of it before.

The article covers all the essentials, from EQ and A/Bing your material against a good reference, to software and hardware choices. But I’m particularly fond of the advice quoted above. In fact, even if you’re not going to bother mastering a track, it’s still helpful to have a trusted outsider give you feedback on your mix.

Most articles on the subject, though, are addressed to engineers, by other engineers and producers fed up with the hammering their mixes receive at the hands of overzealous mastering engineers. For the average music consumer, the matter remains somewhat esoteric.

In his article Imperfect Sound Forever, Nick Southall addresses this, and more importantly why the steady increase in volume is so bad for consumers, from the perspective of someone who just loves music:

Levels have crept up over the last decade though, and alarmingly so. Nevermind is 6-8dB quieter than, say, Hopes & Fears by Keane—to contextualise this, those 6-8dB will make Nevermind sound approximately half as loud… Keane should NOT be twice as loud as Nirvana.

For those why decry the practice, it’s a good sign when writers outside the field of music production begin to address the issue. And Southall has more great thoughts in his follow-up article:

Compression will continue to be abused in the pursuit of loudness for as long as the recording industry believes that louder shifts units. I don’t think the loudness war is causing tangible increases in sales anymore than I think the actual notes and words and beats of music are getting “worse” though … I think this is because the clamour to make music louder has made it less loveable, and in the long run loveable sells more. Record company people sadly don’t always seem to get this

Hypercompressed material does not sound louder on the air. It sounds more distorted, making the radio sound broken in extreme cases. It sounds small, busy, and flat. It does not feel good to the listener when turned up, so he or she hears it as background music. Hypercompression, when combined with �major-market� levels of broadcast processing, sucks the drama and life from music. In more extreme cases, it sounds overtly distorted and is likely to cause tune-outs by adults, particularly women.

One reason to use EQ post compression is so that you don’t have to keep re-adjusting the threshold of the compressor when making EQ changes.

This insightful thread on ProSound addresses the consequences of mixing and mastering in the same room:

Bob Ludwig always used to warn people not to listen back to mastered material in the mixing environment, because any room anomolies (which already would have affected your mixes in the first instance) would be now doubly magnified by the “re-playing” through the same system.
…
This advice would apply in spades to a non-professionally treated room.

Finally, though it ends well, this tale from homerecording.com illustrates why we should be wary of budget mastering offers in the Internet:

I definitely feel robbed. Great!

I suppose use me as a reminder to enquire first and to avoid this online mastering company. I most certainly fell for it. A $60 lesson.

If you listen to a “before” sample that’s completely monaural and muddy and then the “after” sample has a wonderful stereo spread with clearly panned instruments and voices and sparkly highs, you’re listening to a fake. That’s not what happens during mastering, and the guy who posted it knows it.

The tips in John’s article could prove valuable on an internet replete with discount mastering offers aimed at those of us with home studios and tight budgets,

the difference in the mastered tracks is most obvious in the extreme low and high frequencies. Listen to the bass guitar in the High Enough extro, and the string noises at the start of I Meant To Remember.

So, what is this “effect”? Simply, it is a stereo effect that pitch shifts one channel up 12 cents, and pitch shifts the other other channel down 12 cents, then uses a delay of about 25ms. The effect, again, is very much like a chorus, but not quite as obvious.

Here’s an interesting discussion between many of the hr.com regulars about the limits and possibilities in the mastering process.

I have tried isolating the problem freqs using two seperate [Multie Band Compression] plugs as well as multi-level compressor plug. The problem is not one of needed expansion or compression, however. The results with these is really pretty similar as it is with the EQs (yes I tried other EQs than the ones listed); I can only remove the unpleasantness by removing the sound.