Essentials to Creating a Good Mix
This article tries to address a common issue many computer-studio artists run into, which is how to create a nice, well-balanced mix. We've all thought the mix was perfect, only to find that when played on another stereo system it sounded like garbage! How frustrating... Well after years of messing with this, I think I've come up with a tecnique (or two) which will enable the common musician to achieve near-perfect mixes without using expensive studio gear.
The Perfect Mix
The perfect mix could only be created with a set of speakers that had a frequency response exactly the same as the speakers that would be presenting your mix, in an identical room, with the speakers placed identically in the space of the room. Of course this would mean you'd have to play back your mix in exactly the same environment in which you mixed to begin with! The problem with this is of course that you want to play your mix everywhere EXCEPT the room you mixed it in. Now the idea of the perfect mix is drastically altered...
A More Realistic Perfect Mix
Now lets say you had a list of every speaker from which your mix was going to be played, and knew the average frequency response of every corresponding room for each set of speakers. Now you average all of these things together and create your mix in that imaginary "average" room. Theoretically, this would be the ideal place to make your mix sound perfect!
The "Line Theory" of Mixing
So this is a little phrase I came up with, which I call the "line-theory" of mixing. Basically, it goes as follows: Imagine you are trying to draw a line. If I give you only one point, you won't have a clue which way to start drawing it, or if it is even in the right direction - this is what I consider to be the eqivalent of mixing in just one set of speakers. Furthermore, I don't care what type of speakers they are, or how expensive they are - mixing in one set of speakers is as worthless as a line drawn from a single point on a piece of paper. Now I give you another point. Suddenly you have a clue in which way to draw it, however in between the points your pen might stray a little. This is where the quality of your speakers comes into play. More accurate (flatter response) speakers will not stray quite as far off this "perfect mix" line as will lower quality speakers, but it can still be accomplished fairly well regardless of what speakers you are using.
Suggested Speaker Set
Now that I have explained the line theory, how do you use it to create amazing mixes? You get two sets of speakers of course! Now it's not quite that simple - these shouldn't just be any old random speakers. These speakers should exhibit different properties as follows:
- You need a set of speakers that can handle the full spectrum at fairly loud levels.
- You need a set of speakers that can't handle bass too well. (The bass will distort long before the other frequencies)
- You need a system that exaggerates bass (i.e. a low-riding Civic)
- You need a pair of very accurate headphones with a mono/stereo switch (the sound should be incredibly clear, like "wow!" clear.)
The full range speakers will be used to judge the overall mix quality at varying volume levels. Tweak your mix at
each volume level and pay attention to the overall sound of your mix.
The "weak" speakers will be used to make sure your mids and lows are not drowning out your highs. i.e. use these to listen for that "muddy" sound, figure out what is causing the mud, and get rid of it.
Systems that exaggerate bass are valuable for detecting very low frequencies which are needlessly eating up your dynamic range. Basically, any low frequencies which do not add to the music should be lessened until they sound good, even on a system with mad bass. If the bass is clean and intentional, the bass should be booming and tight on these systems. If the bass is merely some unintended sub-frequency created as a biproduct of some other noise, chances are it will sound terrible on these systems and you should attempt to filter it. Filtering out these unwanted low frequencies also enables you to increase the dynamic range of your mix overall. (i.e. turn up the volume across the board without distorting)
The super clean sounding headphones will be used to pick out any sounds that either shouldn't be there at all, and to get an overall feel for the mix. Headphones should be mixed in last, and never tweak any low frequencies while listening to headphones. Remember that the proximity effect can increase or decrease bass frequencies by orders of magnitude, with just a few millimeters difference in the distance from the headphones to your ear canal. Don't touch the bass in headphones!
The Mixing Process
Start your mix out in the full-range speakers. Once it sounds decent, start mixing back-and-forth between your full-range and the detail (weak) speakers. Once the mix is decent in these two sets, add in the headphones to your rotation and keep re-mixing. The more you switch between sets of speakers, the better the mix will turn out. As you switch to another set of speakers, try to focus on a particular sound, and make sure that it sounds roughly the same no matter which set you are playing it out of. This will enable you to catch bad sounds and pinpoint the source of bad or unintended noises. Unless you have a system with a subwoofer available to you in the same room, take your mix out to a car or something and play the mix there. Take note of where the bass is overwhelming and filter it out back in the studio. You will be surprised at how many trips it may take to get it right. The most common error will be to have too much bass, and to filter too little out once you have confirmed it. Take out the overpowering bass until you think it is good, then knock off another 4db or so. Now when you play it back on the subs it will be more reasonable. Once the bass is set right you will likely be able to increase the overall volume of your mix since it will now distort at much higher levels.
Eliminating Bad Phasing
You may have heard that "swishing" sound in a bad mix that seems to grate on the inside of your ear. This is known as "phasing" and occurs when two signals in different speakers are slightly out of phase with each other. This causes your ears to perceive the sound unnaturally, since it confuses your ability to sense the source location of a sound. This phasing effect can be avoided simply by switching your fancy dual-mode headphones into MONO mode. If there is bad phasing in your mix, you will hear it no clearer anywhere else than on your mono-combined channel headphones. (Notice that they have to COMBINE the left and right channels for this to work, ones that simply duplicate the left channel on both ears won't work.) To eliminate this phasing effect, first figure out what sound it is happenning on, then attempt to pinpoint its cause. You may fix it by reversing the phase on one of the channels for the track that is causing the phase effect. Other common cuases might be a stereo flange FX box, in which case you would have to tweak the FX box (or plugin) until the phase effect goes away.
While you are mixing and switching between sets of speakers you should also be changing up the volume. Not only do your speakers respond differently at varying volume levels, but your ears also percieve sound differently. If you only mix at a very loud level, your mix may not sound the same at a mid level. It can sometimes be beneficial to start mixing at an incredibly low level and slowly work your way up to a louder level. This essentially lets you focus on mixing the frequency ranges from the top down.
The Play-Out Tests
Once you've mixed in all your sets of speakers at all sorts of volume levels it is time to play your mix elsewhere. Start on the stereo system in your house, then try some friends houses, as well as diferent cars. (Cars are the worst place to do critical listening, but can often reveal certain frequency ranges that go over the top that will require filtering.) Make notes of anything you notice and check it out later in the studio.