Why Mastering Sucks in the 21st Century

This is a rant. If you don't like rants, don't read it.

The first argument goes like this:

1. Mastering is just a matter of balancing tracks with each other using EQ, compression and limiting
2. I can get mastering EQ and compression plugins free with a pint of beer, nowadays
3. Why would I pay someone else to do my mastering ?

The second argument goes like this:

1. No-body buys CDs any more
2. Nobody listens to albums any more
3. Everybody uses mp3 players and crappy earbuds nowadays
4. Why would I pay someone else to do my mastering ?

The third argument goes like this:

1. I sent my last CD off to be mastered, and it came back sounding no different
2. I sent my last CD off to be mastered, and it came back sounding the same but a bit louder
3. I sent my last CD off to be mastered, and it came back sounding absolutely terrible
4. Why would I pay someone else to do my mastering ?

Case closed, right ?

When I started out as a trainee mastering engineer, over 15 years ago, one of the toughest jobs was explaining to people what mastering actually was. In those days it truly was a dark art, costing you hundreds of thousands of dollars worth of gear just to obtain admission to the club. Nowadays you rip a few tracks into iTunes, burn a CD and you're a mastering engineer, right ?

Hmm.

My first set of replies goes like this:

1. That's some of what mastering involves, yes. I wrote more about it here.
2. You can buy plugins that say they allow you to do mastering EQ and compression, yes. Why don't the top engineers use them ? Leaving that aside for a minute, do you know how to use the ones you have ? Are your speakers good enough to hear what you're doing with them ? Do you have the experience to know exactly what things should sound like in your genre ? Do you know when it's a mix problem and when it's a mastering problem ? Let's try another tack. As a musician or record label, releasing your music to the world is a bit like having a really important job interview, and you need a new suit. Do you buy the cheapest, or the best you can afford ? Given the choice, would you have one hand-made by a master tailor using the finest quality material to fit and flatter your exact build and body-shape, or would you order one over the internet and hope for the best ?
3. Why would you want someone else to do your mastering ?

My second set of replies goes:

1. Actually over 75% of the music-buying public still want CDs. And soon all downloaded music will be losslessly encoded anyway, so it will sound the same as (or better than) CDs.
2. True, no-one listens to albums any more. Instead, people listen to all their music on shuffle. Before long, all albums will be played at the same average level, as it is on Spotify, so you won't have those annoying jumps in volume, except where you're meant to for loud or quiet tracks. So it will be just as important to have your music correctly balanced in comparison to everything else as it has ever been, if not more so.
3. mp3 players will soon sound as good as CD players - see above. And, crappy speakers or earbuds make everything sound crappy. As did AM radio. As poor-quality vinyl and record decks did. As analogue cassette did. As does DAB radio, and as do mobile phones. What's your point ? If recording high-quality audio was important then, why isn't it important now ? Do you WANT you music to sound crappy ?
4. Why would you want someone else to do your mastering ?

My reply to all three parts of the third argument is:

That's because lots of people who call themselves "mastering engineers" have absolutely no right to the title. Putting it bluntly, they don't have a clue what they're doing, and they fuck it up on a daily basis.

For the last fifteen years, customers from every genre and at every level of the industry have sat and watched and listened to me work, asked questions, and offered opinions. 99% of the time they are delighted with the results, and come back again and again. Some of them have ears every bit as good as mine, and the equipment and skills to do the same things that I do to their music. Why don't they ? Other times I have sent people samples, and heard nothing back. Months later they book in for a session because they found it wasn't as easy as they thought to get the results they wanted, even with my example to copy from.

Who am I, Derren Brown ? Is mastering really the world's most elaborate confidence trick ?

Why would you want someone else to master your music ?

This post was inspired by a thread on the Sound On Sound Mastering Forum. Thanks for listening, I feel better now.

Twitter Interview - An introduction to CD Mastering

Yesterday I did a short Twitter interview with @DIY_Musicians about mastering - it was slightly chaotic but good fun, and the people reading seemed to enjoy it. It may or may not have been the second ever such interview in the UK, if @neil_mccormick's really was the first.

Here is the complete text, in case you missed it.

***

DIY_Musicians: Let's jump straight in, Ian. Q: What is mastering ?

ianshepherd: Mastering is turning a collection of songs into an album - by balancing them, not matching them. Also http://twurl.nl/m8bwvo 

DIY_Musicians: Great link, thank you... I was wondering how you would answer that in only 140 characters :o)

ianshepherd: [Grin] Cheating, technically, I suppose !

DIY_Musicians: Q: What do you actually do ?

ianshepherd: I listen to music, and change it so that I like it better :-) Luckily, my customers agree with me, almost all of the time ! 





DIY_Musicians: Q: What are the most important tools of a Mastering Engineer ? 


ianshepherd: My ears, my experience, the monitoring (speakers), the room, the audio equipment (EQ, compressors, DAW etc) 


DIY_Musicians: Q: What's your favourite piece of audio equipment ? 


ianshepherd: My monitors ! B&W 801s - and I use the TC Electronics System 6000 on nearly every job - great converters, great processing

DIY_Musicians :Anyone interested can find out more via... @tcelectronic

ianshepherd: B&W loudspeakers - @Bowers_Wilkins, More info on mastering monitoring here: http://twurl.nl/pr0hjm)

DIY_Musicians: Q: Why is it so important to have great monitors in a great room ? 


ianshepherd: Because you need to be able to hear *everything* - accurately. Otherwise you risk doing something unnecessary or detrimental 

DIY_Musicians: Knowing what you're listening for is essential. Q: Is DIY mastering possible ?

ianshepherd: It's possible, but hard ! It's difficult to be objective about your own material, and hard to get a good setup on a budget 


DIY_Musicians: Q: But, aren't there lots of mastering plugins now ?

ianshepherd: Yes, but it's all about hearing the music clearly and objectively, and having a vision. You need knowledge as well as tools. 


DIY_Musicians: Q: That's something you can learn, right ? 


ianshepherd: Yes, to a certain extent, but personally I think it's also an instinct. I wrote about it here: http://twurl.nl/gnkiki

DIY_Musicians: Thanks for the link - that's great 

DIY_Musicians: Q: Do you have any hints and tips for people who want to have their music professionally mastered ?

ianshepherd: Yes ! Never let digital meters clip (hit zero). Don't use too much compression. Provide 24-bit files where possible...

ianshepherd: ...leave the tops, tails (fades) and gaps for the ME. Always use dither when processing. Use high-quality converters




DIY_Musicians: Excellent advice. Q: Where can people find out more about mastering ?

ianshepherd: Follow me on Twitter ;-)  http://twurl.nl/b3aohf And, here are two great mastering forums: http://twurl.nl/xb2vhr & http://twurl.nl/xm57pc 


DIY_Musicians: Some cool links to take away for further reading - we like that. Thanks for your time, Ian. We really appreciate your support. 

ianshepherd: You're welcome, thanks for asking me ! 

DIY_Musicians: @ianshepherd also runs the Production Advice site, helping you get a better recording & mix http://twurl.nl/jzxdde

***

If you found this interesting, you might also like to check out this interview I did with Pete Whitfield from the Manchester College.

Feel free to tweet me any questions you may have as a result of this interview, or in fact any questions at all about mastering.

Video interview for The Manchester College

Today I was interviewed by Pete Whitfield from The Manchester College, via iChat. We talked mainly about mastering - what it is, how I got started and what gear I use, and what skills are necessary, but also a little about music and social media - blogging, Twitter etc. 

I will also be answering questions (if there are any!) from students at the college all this week on their forum. Thanks to Pete for inviting me.

 

 

My Massive CD-Mastering Mind Map

Everything you could ever want to know about mastering (*), all in one monstrous PDF mind-map file.

It speaks for itself, really.

(*) Or at least, everything that has occurred to me so far !

If you're curious, you can download it HERE.

This post started out as an experiment with a great piece of iPhone software - iBlueSky. I've been using this great little app on my beloved iPod Touch, and I'm seriously impressed. If you're an iPhone or iTouch user who's interested in mind-mapping software, I heartily recommend it. (When they add the ability to manually colour-code branches and type-set the text, it'll be even better.)

I'm also using it to brainstorm ideas for my new, very hush-hush "secret project" - but more on that in a future post.

If there are any questions or suggestions you'd like to make about the map and it's contents, please feel free to comment !

8 Music Mastering Techniques to Make Your CDs Sound Better

How can you make your CDs sound as good as possible ? 

By "mastering" them - meaning, by balancing each individual song against the others in level and sound to create a coherent, satisfying whole.

Many of my posts are squarely aimed at people who want to get as close as they can to having their CD mastered by a professional. However these tips and suggestions are more general and will benefit anyone who wants their CD to sound good - they apply equally, regardless of the level or standard of your mastering skills.

1. Think big - Mastering is about making an album from a collection of songs. Now isn't the time to agonise about the details - whether the vocal is too high in one song, or whether you should add another guitar part to another. Mixing is over - move on ! Think about how songs relate to each other, look for a "line" through them, so they flow convincingly. I often describe mastering as finding the "centre of gravity" of a collection of tracks, and helping them all sit right next to each other. Listen to the overall sound of each song, and work on that.
   
2. EQ and volume are everything - The equalisation (broadly speaking the bass, middle and treble balance) of each track needs to be right before anything else will work. To choose the right EQ, the level needs to be right, but the EQ influences what level you choose. Sounds like a Catch-22 ? It is. So, set the level, adjust the EQ - repeat until happy. Of course dynamic compression is a crucial part of this process - see below.
3. Have an open mind - Normally my advice to people is "don't try to master your own stuff". If you are trying to do it yourself though, throw away all the pre-conceptions and ideas you have inherited from the recording and mixing process, and start afresh. Be prepared to cut swathes through all the detailed decisions and reasoning you've put into the project so far - a mastering engineer gives an impartial, third-party opinion about what's best for your material - you need to try and do the same. Listen to the Big Picture.
   
4. Match vocal levels - When choosing how loud each song should be compared to the others, it's easy to get confused. A great rule of thumb is to balance the vocals. If you can get the vocals for each tune to sound as if they're in the same ballpark, almost anything else will work around them. Where you don't have a vocal to listen to, pick the main melodic element instead.
5. Work fast, be bold - Use broad brush-strokes; listen to each song and make big, instinctive changes. Set the level, choose an EQ and go for it. Instinct is important in mastering, and often your first thought is the right one. If you find yourself going around in circles worrying about the details, it may be best to move on to a different song and come back later.
   
6. Keep it Dynamic - You can master a CD without boosting the overall level at all, and all the EQ and level adjustments will still be invaluable. However most people also want to lift the overall level to be closer to commercial releases as well, and so compression and limiting become important parts of the process. I'm writing a whole series of posts about this, but the main point to make here is - don't be tempted to over-cook it. Music needs light and shade - without Quiet, there can be no Loud. So strive to find the "sweet spot" for your album, where the benefits outweigh the problems compression and limiting can cause. If in doubt, check out my post How Loud Is Too Loud ? Don't let your CD be a victim in the Loudness Wars - no-one wants to be the next "Death Magnetic"...
7. Good gaps - mix it up - The silence between tracks on your CD can sometimes be as important as the tracks themselves. If a gaps are too short, the album can feel rushed and exhausting - too long and the listener is distracted form the flow of songs wondering where the next tune is. Some people swear by two-second gaps, but my favourite rule of thumb is - make the gap equal to two bars of the out-going song. Times to consider breaking this rule are early on on the album, where you might want to build momentum, or after a song with a slow fade. Occasional longer gaps can give the listener time to catch their breath, or frame a change of mood or style, for example. Variety is the key here.
8. Burn Slow, Burn Steady - So your songs are sequenced, balanced, boosted and spaced - all you need to do is burn a quick copy at 52x and listen, right ? Wrong. Different brands of CDRs work better in certain burners than others, and error rates vary widely depending on the write speed. Yet again this is a complicated topic, but on the whole we see the best results burning at slower speeds like 16x, 8x or even 4x. This isn't such a big issue unless you want to use your CD for replication, but avoid the very high speeds, and spend a little more on "name" brands like EMTEC, TDK or Verbatim. If you want to use what we use, these brand-names are no use, though - the company widely-regarded as producing the most reliable CDs of all is called Taiyo Yuden - but not all suppliers can offer them.

If your goal is to try and get a professional result for a CD release, all the above techniques will help you. You'll also need decent monitoring in a reasonable room, and probably to read all my other DIY mastering posts - but you'll find the ideas here equally valuable, even if your goal is only to make your band's demo sound as good as possible, or you just want to make a better-sounding mix tape.

I hope you find them useful, let me know how you get on trying to put them into practise.

 

DIY Mastering Part 5 - How loud is Too Loud ?

As regular readers of this blog will know all too well by now, I am firmly opposed to the so-called CD "Loudness Wars", where everyone tries to get their CD louder than anyone else's by pushing the recorded level higher and higher. This is ultimately a self-defeating process - the CD spec defines a mazimum recordable level, and the harder you push your music up against that level, the more squashed, flattened, crushed and ultimately distorted it gets. Meanwhile there is far less scope within the tracks on the CD for the contrast needed for a satisfying musical result.

BUT as a mastering engineer I spend a lot of my time lifting the level of people's music so that it can compete with the high levels of other CDs out there. And, as I've said in a previous post, I feel that this is actually a positive step for most albums.

How do I reconcile these two apparently contradicting views ? The answer is something I've also said several times before here:

Louder is Better, but Too Loud is Worse

By which I mean - every track (and group of tracks) has a "sweet spot", where it's loudness (and by implication compression, level, EQ etc) is just right. It sounds the best it can be. If it's not compressed enough, then quiet passages won't have enough presence, the mix may not "gel" or have enough impact, detail may be lost, and loud passages will make you wince. Whereas if it's too loud and compressed it can sound squashed and dull (meaning bland and lifeless, not lacking treble) and ultimately fatiguing.

If the idea of using compression on a mix surprises you, it's worth knowing that as a rule of thumb people tend to like quite loud, compressed music, especially for pop and rock. Rick Rubin, who produced Metallica's latest album "Death Magnetic" (currently being heavily criticised for it's excessively-squashed, distorted sound) said in an interview from 2004:

I wish I had examples here to play for you. If I knew we were going to talk about this I’d go through the library and find examples. Ultimately, if you listen on a car sound system or in the mainstream place where most people listen to music—cars, boomboxes sound systems you get at (chain stores), and if you “A/B” the less compressed version to the more compressed version, you pick the compressed version.

And he's right ! He also says, in response to a question about things sounding better on the radio:

Sometimes actually, if it’s too loud, it sounds worse on the radio.

And again, he's right. Sadly, this is exactly the case with Death Magnetic. Clearly this is a delicate issue, and one that even the most respected engineers sometimes misjudge. Music needs just the right amount of compression and level, based on the style of music and the original recording.

So, how loud is Too Loud ? Where do we cross the boundary from sweet-spot into overcooking ? The answer of course is -

Something is Too Loud when it starts to sound worse

But what is worse ? Everything is subjective. Rubin obviously thought Death Magnetic sounded good when he was working on it - perhaps he still does. Lars from Metallica has no problem with it, but I and many others think it's a great shame that so much distortion had to be introduced.

Loudness Measurements

Ultimately the only real way to judge this is to use your ears, but for what it's worth, here are a few facts and figures. I have analysed the loudness of several tracks using a free Mac utility called AudioLeak to measure their long-term A-weighted RMS level. RMS stands for "root mean square" and as applied to music roughly describes the loudness of a musical signal. A-weighting improves on this by taking into account the fact that the ear is less sensitive to bass and treble when judging loudness, and provides a better guide to how loud we think things. A track of equal "raw" RMS level but with more bass won't sound quite as loud, for example, and so will have a lower A-weighted RMS.

Here are some example A-weighted RMS level measurements, with raw RMS in brackets - they are long-term measurements, ie. average values over an entire track. The highest theoretical value possible is zero, and slightly confusingly they are measured down from there, so -10 is louder than -12, for example. So, with the loudest at the top, we have:

-8.6 (-6.2) Oasis - "Some Might Say": Severe clipping distortion
-8.9 (-4.9) Metallica - "TDTNC" (CD): Massive distortion & clipping
-10.4 (-7.7) Feeder - "Pushing The Senses": Heavy clipping distortion
-12.7 (-7.7) Metallica - "BB&S" (Mystery Mix): Slight source clipping
-14.0 (-10) Katatonia - "Consternation": Awesome (clean) sound, massive choruses
-15.3 (-13.1) Sugar - "Fortune Teller": From 1993
-21.8 (-16.9) Metallica - "TDTNC" (GH3) Needs to be louder !

There are plenty of interesting things to be seen looking at these numbers - firstly, the Oasis track actually measures fractionally louder than Metallica ! However by looking at the raw RMS values we can see that in brute power terms Metallica has a higher level - they just have more low-frequency in the sound than Oasis, so the A-weighted value doesn't reflect that. This higher raw RMS may also explain why the distortion on the Metallica tracks is even worse than on Oasis.

Looking at these tracks it would seem that with care the A-weighted RMS can actually be pushed as high as -12 dBFS without obvious distortion. Whether the result is satisfying musically, the numbers can't tell us, though. In my opinion the two best-sounding tracks here are Katatonia and Sugar - "Copper Blue" was a loud album for it's time, but look how things have changed. (By the way examining some SRT masters, the A-weighted RMS typically hovers around - you guessed it, -14 to -12 dBFS)

So, is the answer to "how loud is too loud" actually "any higher than an overall level of -12 dBFS RMS, A-weighted" ?

Well, if we're judging "too loud" to mean "the onset of distortion", then for guitar-driven rock music, yes, maybe. However other genres may suffer more or less and we need to bear in mind that rock is a highly compressed, distorted genre to begin with. I prefer a more dynamic sound personally, so I would pick a level closer to -14 - if it suits the music. Once again, at the end of the day we need to use our ears to make these judgement calls.

Understanding Loudness Measurements

It's also interesting to think about what these numbers mean. The Katatonia track is only 2dB (RMS) quieter than the "Mystery Mix" of Broken, Beat & Scarred", but still has more punch, weight and impact, to my ears. This difference is vastly more apparent comparing to the Metallica CD, and looking at the numbers we can see why. Katatonia has maximum RMS of -8 dB, in the track, compared to an average of -14, giving it a "loudness range" of 6dB.

Compare that with the "Death Magnetic" track. The highest raw RMS level in the track is -2.5 dB. But the average is an eye-watering -4.9, allowing it a range of only 2.4 dB. So the loudest parts can be only 2.4 dB louder than the rest of the track. Katatonia has almost three times the loudness range to play with. No wonder TDTNC sounds flat and lifeless by comparison, whereas when the chorus kicks in on "MyTwin" the impact and buzz it generates is huge. And with almost 10dB to play with, it's obvious why the Guitar Hero version has so much more punch and life - and in fact in my opinion, it would benefit from some EQ and being at a higher level and more compressed, to get it into the "sweet spot". This is why despite preferring the reduced distortion, some listeners still find it lacking.

Ultimately the decision about when the music starts to suffer at the expense of level is one of taste, and requires a judgement call by all concerned. However looking at RMS levels as we have here can be very revealing for a mastering engineer, so I strongly recommend you experiment with AudioLeak or another form of loudness metering - like all mastering facilities we use them constantly here at SRT when mastering. I also recommend you stick around the -14 dBFS A-weighted RMS level to ensure that your CDs are both competitive but also loud-sounding in their own right.

Metallica "Death Magnetic" - Band not present at the mix ?

The plot thickens. In the latest twist in the "Death Magnetic" saga: fans claim the band weren't present during the mix or master.

In a thread on the Metallica forums, user Hetfield1963 says he conducted a phone interview with the band's James Hetfield, and quotes:

JH: I think things came out really good. They’re going to be mixing it while we’re away in Europe. Yeah, and that will be…well,we haven’t done that in awhile. We’ve usually been around for the mixes. I think it will be good for us to step away from it for a while. Let Greg Fidelman do his magic, you know that he is the engineer, he’s going to be mixing it. He is very tuned into what we like and need. He’s very tuned into what Rick likes and needs. So, he’s kind of the point man, which will be really great. We don’t have to worry about what Rick is going to think about this, or Rick isn’t going to have to worry about us battling him on some thing. You know, [Greg], he’s going to be doing the mixing, he’s a guitar player, he gets some great sounds and that’s really helpful.

Elsewhere in the thread, it is also claimed that the band weren't present for the album's mastering sessions, because they were performing at Ozzfest.

The engineer mentioned in the thread, Greg Fidelman, shares a controversial history with the albums producer, Rick Rubin. They both worked on Red Hot Chilli Peppers' "Californication", another CD both revered and reviled for it's sound - harsh, highly compressed and very loud.

Sound familiar ?

The question is, at what point did the sound of the CD move away from the comparatively clean, dynamic "Guitar Hero" version, to the highly compressed, distorted final release ?

Update: Rolling Stone magazine is reported to have an article with Lars Ulrich, saying

the record, more than two years in the making, still isn’t finished. Rubin is overseeing mixes in Los Angeles while the band is in Europe, headlining shows...

Mastering Techniques - Using A Compressor - Part 2

This is Part 2 of a series of posts about using compression in mastering - the first post is here. For a more general introduction to using compression, click here.

Choosing the right compressor settings

Now your ears are focused on what the settings are doing, where should you set them ? Easy:

Adjust the controls until it sounds right

OK, that's next to useless, I know. "What sounds right" varies on the instrument or mix, the genre and taste. There is also a big difference between compressing an instrument in a mix and compressing a whole mix.

Compressing an instrument

For example, compressors are commonly used to even out very dynamic (spiky) intruments in a mix, like a snare drum, say. A snare note has a big spike at the beginning (the transient) created when the stick bashes the skin, followed by a longer sustained sound as the body of the drum resonates. If you push this uncompressed signal too high in the mix, the initial transient may start to sound annoyingly loud and percussive or even distort, if you push it into the red. As a result you can't hear enough of the "thump" of the drum to give it weight and impact.

To minimise this effect, you can compress the signal, using:

• a fast attack time - as soon as the signal starts to get loud, the compressor quickly starts to take effect
• a high ratio to have quite a dramatic effect reducing the spiky transient
• a fast release time to allow allow the compressor to "relax" quickly once the spike has been controlled
• a fairly high threshold so the ring of the drum is not compressed as well as the transient

With a little tweaking, the result should be a much fuller, punchier snare sound - the compressor jumps in quickly (fast attack) and holds back some of the big spiky transient (high ratio high threshold) but because the spike is very short, quickly releases again to allow the main note of the drum to sound. Overdoing it will have undesirable results though - for example if the attack time is too fast, it will remove all the attack from the note, making it sound dull and lifeless. But a bit of experimentation will soon sort this out, and as a result, the snare can be lifted higher in the mix without becoming annoying or distorting - the compression makes it louder. It also sound fuller and punchier, as a by-product.

Compressing a mix

Using settings like the ones above almost certainly won't work well on a mix, though. As a rule in mastering, the aim is for the compression to be as unobtrusive as possible. Usually we aim for a natural-sounding result, where the compression isn't easily noticed. Most final mixes have already had suitable compression used on the individual instruments, so the settings described above will probably result in something that sounds squashed and lifeless, or even pumping and distorted.

Remember in what follows that it's very common to use both a compressor and a limiter when mastering - the limiter catches the very fast transients, allowing the level to be lifted even further, but I'll discuss limiters in the next post. As far as compression goes, for a whole mix I often:

• Avoid very short attack times - and very long ones
• Use shorter release times
• Use low ratios
• Avoid large amounts of gain reduction

The medium attack time allows percussive elements of the mix to punch through, but still controls the overall signal level. If this gets too long, you'll hear the "thump-suck" effect I mentioned in the last post. Shorter release times also avoid obvious pumping, but you need to be careful. If they get too short, there won't be enough control and you may hear the compressor "bouncing" - rapidly triggering and releasing over and over, sounding crunchy or distorted as a result. Low ratios and moderate gain reduction avoid the compression becoming too ear-catching. Time for another rule of thumb:

If you compare the compressed signal with the level-matched original, it should sound better

Meaning not squashed or pumping (unless that's what you want !). You should always level-match the "before" and "after" levels before making your comparison, of course. When level-matching for comparison purposes, it's often worth using the vocals to judge the loudness. Our ears tend to latch onto a voice as the most important element in a mix, so get these as close as possible before comparing. Then listen and ask yourself questions like:

• Which do I prefer ?
• Am I sure one of them isn't louder ?
• Have I achieved what I wanted ? (ie. made it punchier, fuller, with more impact & excitement)
• Does the compressed version still sound lively and exciting, or is it too squashed ?
• Does it sound closer to similar tracks I'm trying to emulate ?
• Can I hear more of the quiet details in the mix, or is it getting "mushy" and confused ?
• Does it still sound natural ?

If you can answer these questions with a positive, you're doing well. If not, try varying some the settings and comparing again. If you still can't get a result you like, try a different compressor - or maybe it doesn't need compression at all.

All of this is very hard to describe in words of course, but hopefully by now you'll have a better idea of how compressors are used, what the controls actually do and what you should be listening for.

If you found this post useful you might also like to watch my free webinar on the more advanced technique of multi-band compression - for more information, click here.

 

Rock Music And Gynaecology

An aspect of the mastering engineer's job that is often overlooked is the "people skills" it demands. Often sessions involve meeting artists for the first time, making them feel at ease, gaining their trust, listening and learning about what they want from the session, and then navigating the delicate process of explaining what you're doing with their music and why. All within only a few hours.

As a mastering engineer who is also a musician, recording and mixing engineer, I have a great deal of empathy with both artists and engineers - trying to make a great record can be a demanding, grueling and sometimes emotional process. People often express insecurities about what they've achieved, be it in the performance, recording or mix, and I always try to focus on the positives in what they've achieved, even where there may problems that need addressing. And I hope that I come across as friendly and supportive in the process.

Recently though, the importance of all this was brought home to me even more strongly than usual. Last month I did a really enjoyable session for an unsigned band called the millionstars - gorgeous, quirky, ethereal british acoustic pop with mild electronica influences - cellos, bassoons, beats, breathy vocals and bass clarinet - how could I not love this stuff ?

The session went well and I felt it had been a great success - the recordings and mixes were excellent to begin with, the material was catchy, clever and varied, and in the mastering I was able to add a whole extra dimension of "width" and "gloss" as Rose and Malcolm had hoped I would. We found we had a lot in common as far as our musical tastes were concerned, we had a good laugh, and at the end of the day we all agreed the album sounded great. Job done, and I went home a happy man.

So, imagine my surprise when I was absentmindedly surfing a few days ago and found themillionstars blog, where on 03/07/08 Rose said:

"we went to get our album of songs "mastered" this week. It is a Dark Art... 

...our good friend Mark compared it to calling out to a total stranger in the street to babysit your children. There you go. Perfect. all those tiny fragments of song in your head, the strands of experience, the homespun, uncomfortably, possibly-inappropriately heartfelt lyrics, brought out and recorded and melded together, and then letting them be played VERY LOUDLY to a complete stranger in a room full of boxes and lights. (One word, girls: Gynaecologist...)

anyway!... we have an album. and it feels like us."

Initially I was amused by this, but then I started to feel a bit uncomfortable - Rose was saying I made her feel as if she was visiting a gynaecologist !?!  I'd hoped my "bedside manner" was better than that... so I sent her a slightly worried message, and thankfully she reassured me that I'd misunderstood.

"oh no... it's just the process, letting someone else hear each strand of a song... [a bit] like doing my music exam grades all over again"

And then she added a comment to her blog:

"[Ian] made me feel as comfortable about my voice, bassoon-playing, glockenspiel-mangling and general flouncing-about-on-the-piano as anyone has ever made me feel.

if you're ever considering mastering anything, look him up...  He'll make it sound beautiful, and soothe your soul."

- which has to be one of the nicest things anyone has ever said about me professionally ! So, all was well with the world again. But it reinforces the point of this post:

Mastering engineers need to be sensitive. 

Not only to people's musical intentions and the genre they are working in; not only to their possible insecurities on a technical level as far as the recording goes, but also about the music itself. Even though people often ask me if I like their music, it had never really hit home in quite this way - until I read Rose's comment - that my customers might feel judged by a mastering engineer on an artistic level as well as a technical one. But of course they do ! Often the mastering studio is the first place musicians have their art listened to by someone other than close friends and family or long-term fans - it's natural they might feel uncomfortable, and it's important to be aware of that. Especially since the critical listening environment and constant repetition puts everything under the microscope even more than ever before.

And finally, we need to realise that the mastering session is actually the first step of a new phase for the artist - all their hard work is about to be released for scrutiny, review and criticism by the world at large, and we represent the first concrete example of that. It's up to us to make sure that transition is as comfortable as possible, as well as ensuring that the music sounds the best it possibly can when it arrives "out there".

It's a big responsibility, I hope I can continue to live up to it.

What is Mastering ?

The art of mastering for CD and DVD evolved directly from the process of "cutting" a lacquer for vinyl pressing, and involves many of the same concepts. But what actually is it ?

Here are some possible definitions of mastering:

• Creating a production master for replication
• Achieving an optimal balance of tone and level
  
• Gaining the benefit of an experienced, impartial ear
• Top/tailing and sequencing
  
• Fixing any outstanding problems from a mix
  
• Making your music sound the best it can be
  
• Making it f-ing loud !
  

So, which one is right? Well, all of them, to varying degrees - except the last one. My favourite explanation is this one:

Mastering is the art of making a collection of tracks into an album (*)

(*) or single, or compilation, or podcast, or catalogue...

This is achieved by one or more of several techniques. As well as technical tasks like ensuring the best transfer from the source and creation of a suitable master, these may include:

• Level adjustments, often using a limiter or compressor
• Equalisation (EQ) to achieve a natural, balanced sound - broadly speaking the right amount of bass and treble, but also much more detailed adjustments, for example to remove unnatural resonance or build-up at certain frequencies, or perceptually improve limitations of the mix. Common examples might include adding "air", or "punch", or adding "edge" to guitars, for example
• Correction of faults - for example removal of clicks, pops or thumps, buzz, hum etc.
  
• Detailed sound restoration - usually only necessary on "vintage" sources, can include removal of vinyl clicks, hiss & distortion etc.
• Stereo image adjustments - this is less common, but may involve widening the stereo image, or (occasionally) adding reverb

Exactly which of these is needed varies from album to album, and even track to track. Some jobs need major surgery, a very few I've ended copying flat from the source. In the later case, did I actually master them? Yes - because I listened carefully, in a dedicated studio using exceptional monitoring, and used my ears and experience to determine that nothing extra was needed. (Actually, more often than not we can spot a source this good within a few minutes of beginning to listen, in which case we contact the artist and offer them the chance of a Direct Transfer instead, so they don't pay for something they don't need.) Deciding to do nothing at all on one or two tracks is just as valid a mastering decision as any other.

However there is still lots of room for confusion and debate. Should mastering engineers:

• Use the minimum possible processing, and keep everything as close as possible to the original material
• Preserve the artist's original vision
• Pull out all the stops to transform a source into what it always "should have been"
• Preserve the original's dynamic range and impact
• Use EQ and compression to achieve major increases in level
• Make everything fit their "trademark sound" ?

Once again my answer is "all of the above" except the last one. This may seem contradictory - surely some of them are in direct opposition to each other ? Not really - because an element of the mastering engineer's skill-set which doesn't often get talked about is intuition. With almost every source I play, I can hear where the artist or engineer was "trying to get" within minutes or seconds. I can hear what they're trying to achieve, and I see my job as trying to help them get there. Using minimal processing, if possible but if not by throwing the kitchen sink at it, and all combinations in between - always staying true to the original mix.

The issue of levels and compression is a good example of this - there are lots of easily available limiter and compressor plugins now, but many of people complain that they ruin the sound. Mastering engineers use very similar tools to achieve their results, and claim that they make things sound better. How can both be true? Partly because there is still a distinction between the tools - mastering studios typically spend thousands of pounds on a single compressor, whereas for the same money you can buy an entire suite of plugins - but also because we are constantly honing our skills to use the tools transparently, and our listening environment to be able to hear when it's working. To some extent, the skill of a mastering engineer is to achieve an appropriate level for every track , sometimes reducing the dynamic range in the process, but make it sound as if the final result is actually more dynamic. Or to make major EQ adjustments, without changing the essential qualities of the original.

So, you might ask - what's the point of paying for something that can be so subtle ? There are several answers to this:

• Often it's not that subtle ! If I'm doing my job, the mastered version will simply be better than the original, while retaining everything that was good about it.
• Where the difference is less obvious, it will only be difficult to hear when level-matched. The importance of increasing the level of a track to it's own particular "sweet spot", without pushing it over the top, is hard to over-emphasise. Doing this for all of the tracks in an album, and getting them balanced perfectly against each other in their final sequence is even more important and valuable. This needs to be done with great care and skill though - it's almost impossible to achieve this simply by pushing the level up into a plugin.
• Ideally, the differences should be subtle. A truly great mix only needs the slightest of tweaks, but even these minor adjustments, over the course of a whole album, add up until the sum is greater than the parts.

As I type this I'm struck again by the inherent contradictions of the job. It requires you to be entirely humble - I start every session by listening carefully to the source and thinking "what's good about this ?"; but also supremely arrogant, making changes to a mix that someone has sweated blood over for perhaps weeks or months. It requires deep technical knowledge, but many of the judgements made are largely aesthetic and artistic. It means knowing when something ain't broke and not trying to fix it, but also knowing when to roll up your sleeves and get your hands dirty...

What is mastering ? Has this post helped explain it at all ? Who knows...

Mastering The Orb - Complete BBC Sessions

Please forgive me a self-indulgent nostalgia post:

I love my job !

I vividly remember hearing "Little Fluffy Clouds" by The Orb for the first time - it was in 1991, and coincided with the beginning of one of my favourite times in UK music. I was in my second year at university, and it was the same time that Orbital's Brown Album came out, U2 released Achtung Baby, Screamadelica by Primal Scream was huge, Resevoir Dogs and the Director's Cut of Blade Runner were released, I was listening to "Copper Blue" by Sugar, Bowie's "Hunky Dory" and ""Mixed Up" by the Cure, and They Might Be Giants released "Flood". My friend Dan (nowadays I master his albums) introduced me to "My Life In The Bush Of Ghosts" by Byrne and Eno - and with hindsight, it was the year I started mastering.

That's not strictly true of course - I actually started work as a trainee tape-op at SRT roughly two years later, and mastered my first album for paying customers a few months after that. But I was mastering, nonetheless - or rather, re-mastering - in my own fashion. Bootlegs, to be exact - purely for my own listening - of Prince, no less, at various gigs on the Lovesexy tour and numerous after-show parties. I bought these in dodgy indie record shops for a pittance, on analogue cassette (remember those?) and then discovered I couldn't listen to them, because they were usually dull, distorted, off-azimuth and copied at such a ridiculously low level with no noise reduction that they were bathed in hiss as a result !

So, I would borrow a friend's ghetto blaster and use it's primitive 3-band graphic equaliser to copy the crappy transparent plastic TDK D90 original (remember them?!) across to a lovely new silver SAX90, making improvements as I went. Boosting bass, correcting L/R balance, probably rolling out the top end during quiet sections to hide the hiss and boosting it again in the loud bits to counter the inevitable distorted mush that came with them...

Those were the days. And in fact, nowadays I do pretty much the same things, but with gear I could never even have dreamt of back then. Samplers were the new big thing - I remember tearing my hair out my with best friend Ben (I master his albums now, too) trying to get a multi-patch set up in the cutting-edge Yamaha ____ - and it would always crash solid after about two hours work. I recorded albums for friends on a Tascam 8-track cassette machine, and thought myself lucky to actually have access to a DAT machine to mix down to.

"Little Fluffly Clouds" conjures up all of that for me, in a heartbeat.

Anyway, here I am, nearly twenty years later, actually mastering The Orb for real - listening to a version of "Little Fluffy Clouds" from the the 1998 Steve Lamacq sessions - and even better, "A Huge Ever Growing Pulsating Brain That Rules from the Centre of the Ultraworld" from the original 1989 Peel Sessions (and everything in between) for a new double-album release. It's not distorted, it's not bathed in hiss, it doesn't need much bass and it's certainly not on analogue cassette, but it's still benefitting from some TLC from me. Which feels good.

Perhaps it's a sign of the times (hah!) that although I still remaster Prince bootlegs at home - purely for my own listening - nowadays it's with with ProTools running on a MacBook Pro, from where they go directly to iPod Touch and sound fantastic - but oddly enough, it's a CD of the same gig.

I love my job.

DIY Mastering Part 4 - Mastering Speakers and Monitors

The most important tool a mastering engineer has (apart from his ears and expertise) is the monitoring, meaning the speakers, amps and converters. We debate all of these at great length between ourselves, in online forums and down the pub, but without question the speakers have the greatest impact on the sound. (They need to be well-placed in a decent treated room, but I already covered that in my third DIY post.)

This post won't enable you to choose a set of speakers by reading specifications or manufacturer's blurb, but hopefully it will give you an idea what you should be looking for, and why.

So, what are suitable speakers for mastering ? Well for example we have B&W Matrix 801s in Studio 1 at SRT, Genelec S30Ds in Studio 2 (In general I don't rate Genelecs, but the S30s have a ribbon tweeter and are in a class of their own). Other common names include ATC, PMC and Dunlavy. What all these monitors have in common (apart from costing at least as much as a large family car !) is that they have:

1. Flat, or neutral frequency response - meaning their response is very even over the whole audible range. So, for example, B&W 801s come with a graph measuring their response - it only varies by +/- 1 dB from 20 Hz to 20 kHz.
2. Acurate phase response - meaning that the stereo image is very detailed, giving an absolutely solid mono center image, but also a deep, convincing "three-dimensional" soundstage - at least, on a decent recording. The stereo imaging in our studios is so good that it's common for people to ask if some of the sound is coming out of the center speaker (used for surround work), even though they are listening to pure stereo. And on the occasions where a mix element is accidentally phase-reversed, it leaps out and draws attention to itself.
3. Clean, controlled dynamics - with only minimal distortion introduced, even at high listening levels. (Using a suitable amp is important for this, too, of course.)

Of course there are many other aspects of speaker's capabilities I could list, but it's almost more important to realise that these characteristics mean mastering speakers should be:

1. Revealing - allowing you to hear details you'll miss on other speakers - faults, like clicks, hiss and distortion; but also the positive sides of the recording - accurate stereo imaging, "depth" (meaning the impression of a three-dimensional sound field), impact and dynamics. Listening on a mastering system should almost be like wearing headphones, in this respect.
2. Clinical - Mastering speakers don't make things sound good. Unlike speakers for tracking or mixing, they shouldn't add "vibe", or "feel". Often they might be described as "bland", "boring", or at best "civilized". In fact, they are reliable and acurate. Only the very best recordings will sound good on them ! In fact that leads us neatly to:
3. Unforgiving - It's often shocking to hear how bad many recordings sound on a mastering rig - the uncompromising accuracy uncovers limitations masked by lesser reproduction systems. While this won't necessarily make for a very satisfying listening experience, it's essential for the mastering engineer to hear and correct any problems or limitations in the original mix.

Together, all these requirements add up to help the engineer achive translation - when it sounds it's best on the mastering system, it will sound great everywhere else, too.

So, if you've got this far, you're probably thinking "how the hell do I choose speakers which meet all those criteria ?". If you can't rely on printed specifications alone, this is a tough question. Until you're learnt exactly what a recording should sound like, it's hard to recognise a pair of speakers that make it sound that way.

Probably the first piece of advice is to get some recommendations. This post was inspired by a thread on the Gearslutz mastering forum asking about mastering speakers, and places like this or the SOS forums are good places to start - perhaps less than £500 isn't really realistic, though! Several of the speakers I mention above are available second-hand for "reasonable" amounts of money. My personal favourites, B&W, have ~35 staff working constantly on research and development, and the advances they make for their most expensive speakers always filter down to the cheaper models. I have Series 2 601s at home and am frequently amazed by how good they sound. Not that I'm suggesting you use them for mastering, but considering the difference in size and price, there's almost certainly something in the 600 range to suit.

Next - listen ! Find a showroom where you can test a few different speakers, ideally in the same room, and listen to various different tracks you know well. Even better, get some on demo and try them in your room. Remember you're looking for accuracy, not excitement - mastering monitors reveal limitations that others don't. Choose a range of recordings and be objective. "Sledgehammer" by Peter Gabriel is a great-sounding track, but it has very tight, controlled bass, so if the speakers give it a thundering bottom end, they aren't flat. "Dummy" by Portishead is a classic album, but it's almost entirely in mono - that should leap out at you. Maybe even take a CD with a few test-tones on it - for example a sine wave sweeping up from 20Hz to 20kHz will not only give you an idea about the speakers frequency response, but may also reveal a few buzzes and rattles along the way. (Don't play it too loud, though, or you may find yourself paying for some blown tweeters...)

Finding the right speaker in your price-range is a major challenge for a would-be DIY mastering engineer, but once you've worked with truly acurate monitoring for a while, you won't want to go back.

Christine Tobin - The Secret Life of a Girl

An excellent (and well-deserved) review of Christine's new album which we mastered back in March, as I mentioned in my first post. It's always good to see one of your artists doing well - I love this record, and I wish Christine every success with it. Maybe this will be the breakthrough she deserves !

And while I think of it, Phil got a great review too !

Christine Tobin, Secret Life of a Girl

 (Babel) 

John L Walters
Friday May 16, 2008
The Guardian

Dublin-born singer Christine Tobin is a jewel of the London jazz scene, streets ahead of the pack, but she deserves better. She should be on a global stage, rubbing shoulders with fellow troubadours like Cave, Mitchell and Cohen. And while her current 15-date tour should help broaden her UK fan base, this is an album that could break through to a bigger, international audience. Tobin's eloquent songs are framed by masterful arrangements and beautifully recorded to make the most of the content. There's no self-indulgence: it's all about the songs. Dave Whitford's sonorous bass and Phil Robson's self-effacing guitar are the perfect match for Tobin's rich, dark-hued vocals.

Highlights include the swampy Bye Bye; the Corner of an Eye, with its archaic "spring reverb"; and a delicious cover of Cohen and Robinson's Everybody Knows. Yet it's a tribute to the quality of Tobin's writing that there are no weak spots in this excellent collection.

Mastering Software Part 1 - Metering Levels and Loudness

I mentioned the Orban Loudness Meter on the SOS forums, and thought it would be good to start a series of posts here on useful mastering software. So, first up - metering apps. Several of the best editing packages include decent metering, for example Wavelab, and Audacity, but here are a few personal favourites:

•  Orban Loudness Meter Great (free!) utility includes a PPM meter, VU meter, ITU BS.1770 meter and CBS Technology Center loudness meter - it's fantastic to have access to these less common metering systems, which offer measurements of perceived loudness, which can be more useful than pure RMS. (Plus it runs well under Parallels on my MacBook Pro ;-) 
• Pinguin Audio Meter Not free but comes in several flavours, the Pro version includes an incredibly detailed spectrum analyser, audio phase correlator (more in a later post), PPM & VU monitoring plus a specrogram. Interestingly, Pinguin have done research to suggest that RMS is the most reliable way of measuring perceived loudness.
• Speaking of Spectrograms, there's Spectrogram - and Audacity has this capability, too.
• Finally, the fantastic (Mac-only) AudioLeak - an Leq (Long-term Equivalent Level) Analyzer for audio files and sound input streams. Swiftly discover the average RMS of an audio file, and it's A-weighted counterpart. Just watch out - by default it displays a combined mono value which reads higher than other applications like Wavelab - I usually use the average of the left & right values - they should be almost identical if the L/R balance is right, anyway. Also great for DVD Producers wanting to find the right dialnorm setting for a Dolby Digital encode.
• Update - here's another one - the SSL X-ISM meter. This is useful because it includes checking for inter-sample peaks. This is well-explained on the page I linked to, but briefly: strange as it may seem, when audio has been heavily limited and is peaking at (or very near to) zero, it is possible that the reconstructed analogue output actually peaks above zero. (In theory, up to 6 dB higher !) In cheaper players, MP3 encoders and other utilities, there is often no headroom allowed for this situation, and unwanted clipping can result. This meter will help you watch for this effect and avoid it. As a rule of thumb, don't allow your audio to peak higher that -0.3 dBFS.

Coming soon - how to choose a mastering studio.

DIY Mastering Part 3 - Room Acoustics, Treatment and Layout

This is too huge a subject to cover properly in a blog, but if your monitoring environment isn't working well, you'll never be able to make good mastering (or mixing) decisions, so before you start considering tools or techniques, you'll need to get the room working reasonably well. Here I'll try to give some short but useful pointers and links to good, more detailed information.

The Room:

1. Needs to be a decent size - at least 3m x 4m, say.
2. Needs to have good proportions. Square is bad, a rectangle is better unless it is twice as long as is wide. All shaped rooms have "nodes" - certain frequencies which are emphasised or minimised by reflections between the walls. The dimensions of the room determine which frequencies will be emphasised, and the goal is to spread these nodes out as much as possible, to give the most even response. There is a great free utility called ModeCalc which allows you to calculate the room nodes for a given room, and the same page has a great introduction to the subject. Ideally, you could build "splayed" plasterboard walls to give a wedge shape which reduces the nodes even further.
3. Needs acoustic treatment. Every room will benefit from some acoustic panels - you can make these quite simply yourself using high-density fibreglass ("rockwool") mounted in wooden frames, or buy them from a company like RealTraps, who run the site that the ModeCalc utility is hosted on. These "bass traps", or more accurately "broadband absorbers", will further even out the frequency response of the room, enabling you to make better mixing and mastering decisions. Foam panels may also be helpful but are far less effective, especially in the bass end, where rooms have the most problems. Egg-boxes are useless !
4. Needs the speakers in the right place. They should be on a shorter wall, not too tight into the corners, equally spaced from opposite walls. I've seen several very theoretical methods of determining this, but perhaps the best advice is to get a recording you know well, play it at your chosen reference level, and move them around till they sound "right".
5. Needs a good listening position - equally distanced from both speakers, obviously, but not in the middle of the room. Whatever the shape, some bass frequencies will cancel most strongly in the middle of the room, so it's almost always a bad mix position. If you are one third of the room length away from the speakers, you'll be off to a good start.
6. Needs the right materials. For example, Pro studios use very expensive acoustic panels to control the sound by reducing unwanted reflection from smooth plastered walls. A cheaper alternative is to put carpet on the walls, with the idea of "deadening" the sound. However this isn't always a good idea in a mastering room - since the idea is to get the best possible result for a "normal" listening environment, a certain amount of reflection in the room is important, otherwise you'll be tempted to add too much high frequency to everything. Heavy curtains are probably a better idea for controlling the "liveness" of the room, not least because you can easily change their arrangement and effect on the sound in the room.

All of the factors above affect the way your room sounds, hopefully for the better ! In a later DIY post I'll describe a few simple tests to help you check if your room sounds good.

SADiE acquired by Prism

This post

http://www.sadie.com/news/200804_1_prism_sound.html

says it all, really - this is great news for the pro mastering community, and for everyone at SADiE. Prism has impeccable audio credentials, and is even based in Cambridge, just down the road from SADiE HQ. I'd like to wish them every luck in the future.

On a less positive note our Nakamichi tape deck is on the blink, right when we need it to do some transfers - so we borrowed another one, which is also playing up !

But on the plus side I'm doing lots of classical re-compilations for Universal at the moment. In recent years classical mastering work has been pretty thin on the ground, so it's a pleasure to hear some of the old favourites. Universal now have their entire classical and jazz catalogues available online - over 100,000 albums...

More DIY mastering next post.

Currently listening to "Diamond Hoo Ha" by Supergrass.

Mastering The Split Knee Loons with John McCoy

It's not every day in your career you have the chance to say you've worked on truly legendary material - Wednesday 19th was one of those days.

It was a session which has been on, then off, then on again - one I've been looking forward to ever since I supervised the copying of the original reels over a year ago - mastering the unparalleled Split Knee Loons ( "The best live band EVER!" ) album "Loon Knee Tunes".

Supervised by the almost-equally legendary John McCoy ( Gillan, Mammoth, GMT ), the CD includes the entire, previously unreleased album, plus several astonishing bonus tracks, perhaps most notably their epic live performance of "(She's A Real) Eggtimer" at the hallowed Liverpool Empire. Previously only available in it's restored form from the original sh***y brown vinyl (now a much sort-after collector's item) this one really benefited from the new analogue reel transfer. It was also a particular pleasure to hear more of the work of Blind Frank Mellonhead, who guested on "Norwegian Wood" on Eat This's album, which I mastered last year.

It's always a pleasure to work with John, and it was great that Stix was able to drop in - 'ello Mate ! Now it's finally going to be released after 27 years, I'm confidente that the hordes of eager fans won't be disappointed with this album - truly, they don't make them like this any more.

DIY Mastering Part 2: Before You Start

Before getting into more detail, there are some ground rules to be covered. All of these are important guidelines for any mastering engineer. I'll spread them over a few posts, but we'll start with rules for before you start mastering.

1: Always use a fixed listening environment

Which means level, room, monitors - the whole thing. Mastering is the art of turning a collection of pieces, songs, tracks, into an album. (Or single, or EP...) We're trying to judge impact, pace, atmosphere, dynamics and timing ( amongst others ) - in fact, as a professional mastering engineer I'm almost trying to second-guess the artist. To make a fair and accurate judgement compared with all those other discs, we have to be 100% confident we know what we're listening to, which means eliminating variables in the listening environment. The same goes for any room used for mastering - it needs to be as good as possible.

I'm going to cover room acoustics and treatment in a later post, but the first and most significant thing to control is the level - ie. how loud you listen to the music. I have two levels I master at - one is 12 dB below the other, and I switch between them throughout a session. The exact level you use isn't critical, but it needs to be consistent. (For the technically minded, use an SPL meter and generate pink noise at -18 dBFS. In my room this corresponds to a C-weighted SPL of 79 dB SPL.)

Then listen long and hard to some good CDs. Figure out which ones you consider to sound perfect, which ones sound too loud, which too soft, which too bassy, which too bright. You might decide to use a slightly higher or lower level than I've suggested to suit your comfort or taste, but there are very good reasons for sticking close to this reference level.

You'll probably find that a large number of recently mastered "classic" albums sound absolutely fantastic at this level, and also that many of the newest sound uncomfortably loud - check out my first DIY post for more about loudness.

Once you've settled on a level - stick with it. If you work at it for long enough you'll develop an instinct for the perfect level for any piece of music, and more importantly you'll avoid being tricked by the Fletcher-Munsen effect; in a nutshell, quiet sounds appear duller and thinner - ie. if you master with your level too low the chances are you'll add too much bass or top, and vica versa.

2: Use full-range, FLAT monitors

A CD is capable of reproducing a frequency-range of 20 Hz to 20 kHz. Your monitors need to come close to this - anything they can't reproduce, you can't hear, and may misjudge. In a pro mastering room this generally means the monitors will be big, and expensive. (In most mastering-houses they may easily cost more than a family car !) So try to choose neutral, accurate speakers, with a flat frequency response - perhaps bland-sounding to some ears, because that way you know it's the music that sounds great, not the monitoring. B&W make some superb hi-fi speakers which could be suitable for DIY mastering.

Ideally you should master on different monitors than you mix on, and even in a different room. This is partly to get a fresh perspective on what you're listening to, but also it means that if there are problems or limitations with the monitors you mixed on, you are more likely to spot this. If you're going the DIY route obviously this won't be easy, but the next best thing is to listen to your mastered audio in as many different places as possible. If it consistently sounds boomy, it probably has too much bass. But problems that you only hear on one system are more likely to be to do with the setup of that system.

One good tip is to setup your home stereo speakers in the mastering room, assuming they're decent quality - since you listen to most of your music on these, you may be much more sensitive to mastering judgements listening to them. Even listening on a favourite pair of headphones can be useful. But remember the golden rule - pick two mastering levels (three at most) and only use these when mastering.

3. Use a loudness meter

As I said in my first DIY post, perhaps the most important thing a mastering engineer does (apart from put the right tracks on the CD, in the right order !) is to choose a consistent, musical level for each track. The most important tool for deciding this is your ears, but meters giving you an objective measurement of the level are invaluable. Most people will probably find it easier to use the digital metering offered by a piece of software, but I still have a soft spot for the analogue needle, or VU meter.

Whichever you decide on, the most important think to know is why bother to use a loudness meter ? Because the absolute and relative loudness' of tracks on an album have an immense effect on their perceived sound and a peak meter is virtually useless for judging loudness. The classic example is the human voice - a very quiet voice can have an extremely high peak level. It "looks" loud on a digital meter, but it sounds quiet. A VU or digital loudness meter looks much more as things sound in terms of level. If you learn how the meter relates to loudness it'll help you make good judgements in "mastering".

More guidelines in a later post...

Galactic Symphonies - Kaoss Pads and Poetry

So, Richard's session proved to be even more fun than I expected ! The project was a collaboration with unique 60's poet-lyricist Stephen Kalinich, and comprised a fascinating improvised mixture of Kaoss Pad manipulated soundscapes, gentle acoustic guitar numbers and full-on almost-rap sections. Where things got really interesting is that the release is to be a double-sided disc - CD on one side and DVD on the other, so we had a studio recording to master, plus a live performance for the DVD.

Initially Richard had thought of the live version as more of a bonus to the CD release, and anticipated spending less time on a "rough cut" master. However since the recordings were made he had started to enjoy the live performances more and more, and decided to spend more time on them. At the end of mastering the studio version I gave him a brief demo of how the live performance would sound if we converted it to surround-sound using the System 6000's "unwrap" capabilities, and he was hooked. The processing he uses on the live guitars, especially the Kaoss Pad (*), worked fantastically well with the unwrap, creating a really convincing 3D soundscape. So an extra day was booked and now there will be 3 versions on the disc - studio stereo on the CD, and live stereo and surround-sound on the DVD.

(*) Richard uses two of these while performing - "playing" them with his toes !