You've written your track, mixed it down, compressed, bussed and EQ'd until you're sure you can't take it any further - but it still doesn't sound quite right. In fact, it sounds slightly like a dustbin falling down the stairs. But they'll fix all that in mastering. Won't they?
There seems to be a common, and increasing, misconception about what mastering really does, and how it will affect a track. It's pretty often that I get a track from a budding producer who offers it up with the caveat that "it's not mastered yet, so the drums don't really sound great, and it doesn't have too much punch..." Unfortunately, in most cases like this, mastering will do little to help. It's sad, but it's true. So what will it do? Well, in brief, since you've no doubt heard this before, it's the last little polish on a track before release. It may fix some rogue volume peaks, squeeze a bit more volume/stereo/bass out of your mixdown, or balance things up a touch. With luck, the mastering engineer should also be able to sweeten things up a little with some EQ or a dab of compression, but these are subtle, subtle solutions and won't massively change the feel of your track. Bear in mind that in theory, if you did the perfect mixdown, it wouldn't need mastering at all!
So after all that, is there any point to mastering? Undoubtedly. A good mastering engineer will have a fantastic set-up, from room acoustics, to monitors, to high end valve equipment, and, more importantly, will have spent the last 20 years engineering and listening critically to music for 8 hours a day. The upshot of that is that he'll be far better placed to catch any mixdown issues you might have missed while you were deep in the zone. The high end equipment will also enable him to push a limiter slightly harder, or be more accurate with corrective EQ, than you might be able to in your home studio. Even just the process of running the track through some high end valve kit will help add warmth to your beats.
So, the important thing to remember is that mastering won't make a poor sounding track into a great one. But it can make a good track sound better.
In terms of what you need to be doing at the mixdown stage then, this all basically means that there are no short cuts. If your drums lack punch, then it's best to go back, take the compressor off and have another look. If you're lacking clarity at the top end, then examine each of the elements individually.... you get the picture. Basically, if you think something doesn't sound as good as it could, then don't leave it to the mastering engineer to fix!
Some important things to consider before sending a track to be mastered are to not have compression on your master output (unless you write through a compressor from the start). Make sure the track is not peaking at 0dB either - the engineer will need headroom to boost EQ's and so on; -6dB is a more sensible level.
If you can manage it, a the best thing would be to attend a mastering session. This will really give you an impression of exactly what mastering does, but more importantly, what it's capable of, and how you can better tailor your tracks to the needs of an engineer, so you can get the best result possible. Even if it's in the next city, it will be well worth the cost of the train ride for the insight you'll gain. If you're arranging this, be aware that there is currently something of a price-war going on in mastering these days; new options are springing up very frequently, offering ever-cheaper prices. Many of these will be run by great engineers, but not all - so make sure you get a couple of recommendations first. If you're going to attend a session, it may be worth paying slightly more to go to a big studio where you can see all the expensive kit first hand!
Once you get your mastered track back, it's useful to reference it against your original mixdown, so you can see what he thought was necessary. Listen closely - did the engineer take a scoop out of the mix at 200Hz, or perhaps boost the treble? This will have been done for specific reasons, so bear it in mind when you're next mixing down a track!
Hopefully this article has given you a small insight into what mastering really means to a producer, and how it's not a magic bullet that will fix all your mixdown mistakes, but can give you that last 5% on top of your already good mix. Now go back and take another look at those drums!
