Online Mixing & Mastering

What are stems and why should I care?

Stems (or Stereo Masters) are the recorded audio representation of sub-mix groups on a mixing desk, where you have a number of stereo tracks each assigned to drums, vocals, guitars, strings etc as they exist in thier final, mixed state. The idea is that you can take a set of stems, press play, and all the tracks add up to the final mix of a track. They've been in use since the 60's to enable labels to easily produce a tweaked/instrumental/acapella tracks without having to go back to the full multitrack and redo non-printed effects. With the advent of remixing, it's almost industry standard for a label to require a comprehensive set of stems alongside a mixed/mastered track to enable them to get full use out of thier investment, and most dance music is produced with a full 'remix pack' of stems alongside. Basically, if you've any idea that your track could even possibly be released, you should print stems. It also helps when you're putting music up for synchronisation opportunities, which you really, really should do. Get in touch with Sentric music publishing, they're lovely. There are various ways to print stems depending on your set-up, a quick web search will tell you all you need to know.

What is Stem Mastering?

Straight mastering is working with a single (usually) stereo audio track. One of the central tenets of mastering is that "everything you do to one thing affects another". What this means is for example, if you've got a cymbal heavy section that sounds like its a big, hissing mess, no matter how carefully you EQ the offending high frequencies, you can't help affecting the same frequencies of another instrument, such as the sibilance ('ess' sounds) of a vocalist to some degree. This is really something that should have been addressed at the mixing stage, and if you've easy access to your mix, go and fix it. If you don't, but do have stems (see above), mastering using the stems will produce a better result, as the knock on effect is limited to just the stem being processed. "Isn't this mixing?" Not in the biblical sense, but in part, yes, though the idea is that a mix is artistically 'finished', and mastering of any kind shouldn't go overboard to change it's essential make-up. People charge a bit more for stem mastering, as it's rather more legwork.

Multitracks are not stems!

Just because your DAW has a function that refers to 'rendering stems' doesn't mean what you're spitting out are stems - as I mentioned above, the term stems refers to mixed down subgroups of related tracks, such as vocals, synths, guitars....individual tracks are multitracks or 'multis'. I put an upper limit of around 10 stems for stem mastering, and it needs to be a finished mix ready for mastering. You can't send me something for mastering and then ask for mixing tasks like reverb! It's not a cheaper alternative to a mix.

Levels and loudness wars - what's the beef, Keith?

"Loud music sounds better". That's the long and short of it, though as most things in life, there's a lot more to it. It's a scientific fact that if the human mind perceives 2 pieces of the same music, we will very often state that the louder of the 2 sounds 'better' somehow. Over the years, this has led to the overall volume level of recorded music increasing to the point where the listener is presented with a brick wall of volume with no variation (dynamics). This sucks for mastering engineers, especially us modest bunch who offer free samples and hence get compared against each other as a matter of course (nothing wrong with that at all, done it myself) but unless you the customer is aware of, and can to some degree control the natural response to 'louder music' a bit, you can end up with a master that's on first impressions 'better' but ultimately flatter, not pleasant to listen to for very long, less engaging and emotionally dull. The easy test is to listen to the groove of the music, dance to it, see which one 'moves you' better. Seriously. Watch a video of Bob Katz working, his body is a finely tuned groove-o-meter that starts moving as soon as playback begins. If, however, your track is entitled 'Chainsaw PA destructor (Rabid Hellcatbastard mix)' and was recorded in a working steel mill, I will happily turn it up to 11 - as I said, I've very broad sensibilities.

How should I prepare my tracks for mixing and mastering?

For mixing, it's important to say that you need to have 'tracked' your mix to the point where I really don't need to do things like quantise or nudge your drums about, splice vocal takes together or re-record parts, (though I don't mind doing a little tidying), as that's all really a seperate stage of production. I certainly can do this, but we'd need to talk about rates.

Mixing wise, I would prefer a set of mono or stereo (depending on the channel configuration) WAV or AIFF files at whatever bit and sampling rate you already have them in (16/24 bit, 44.1k/48k, I'd prefer nothing bigger than this) and each track absolutely MUST start exactly at the beginning of the song to enable me to line up all the channels correctly. This means that single triangle hit at 4:15 must have a completely blank track right from the start. You can bounce down stuff onto sparse tracks if you like, so that kazoo solo at 2:37 can go on the triangle track and the saxomaphone intro riff is fine on there, just don't cram too much on a multi-use track. You may have to bounce tracks down or extend regions to the start to achieve all this, and it's worth looking for different methods, as you may find a really, really easy way. For instance, I hate it with a passion, but Fruity Loops Studio has an export function that in one fell swoop renders all tracks to multitrack wavs, really handy.

If there are strong effects/processing that you really want to be prominent in your track, such as a pumping side chained compressor on your nu-disco epic, or a massive wash of reverse reverb over your nu-shoegaze opera, then leave it in. All other EQ and compression/limiting, leave it out. General purpose reverb and subtle delay effects are a very useful tool for me in mixing, and I'd rather make the decision to use them myself, but if there's something very specific you want that you're already happy with on your track, leave it in and I'll work with/around it. Same goes for big spacey multi effects - if it's already sounding great to you, I'm unlikely to improve on it by trying to build it from scratch, so leave it on and I'll work with it.

If you're sending stems for mastering, much of the same applies - make sure all stereo tracks are complete and start at the same place, and see the 'mastering' requirements below.

For mastering, much of the same goes - I'll take your pre-master mix in whatever WAV or AIFF configuration you have (if you've yet to mix down, 24bit/44.1 or 48k please). Unless it's there for strongly creative use, please strip all EQ, compression, limiting, reverb and enhancers off the main mix bus and make sure that the master level meter is roughly between -6db and -3db during loud sections and at no point clips.

Mate, all I've got is my old bands demo from 1992, can you...?

I'll work with what I'm given and do my best, you'd be surprised what I can do with very marginal recordings. At the end of the day, you don't like, you don't pay.