When your tracks are ready for mixdown, you could provide a rough mix to illustrate what you want the professional mix engineer to achieve. If this is your choice, your first step could be to listen relevant reference tracks to warm up the ears. To enhance your hearing sense, you could turn the light down and close doors.
A mix engineer will typically solo each track one at a time, and take notes of any weaknesses and strengths. A good starting point is to set up shelving filters on each track and lower the frequency of the low shelving filter until it changes the sound. To find the sweet spot, the frequency can then be increased until the bass is more noticeable and leave the final frequency half way between those two frequencies.
A multiband sweepable parametric filter, can then be set at low frequency and narrower bandwidth ('Q') with the gain all the way up. This enables the mix engineer to find the characteristic frequency of each track by increasing the frequency until the track plays at its loudest. It is common to broaden the bandwidth and bost that frequency a few decibels so that it can heared clearly.
Set up group channels and assign the following tracks to to each channel.
Group 1 - Lead vocal
Group 2 - Bass instruments (bass guitar, keyboard bass)
Group 3 - Kick drum
Group 4 - Snare drum and toms
Group 5 - Background vocals
Group 6 - Acoustic string instruments
Group 7 - Percussions and cymbals
Group 8 - Clean electric guitars
Group 9 - Distorted guitars
Group 10 - Keyboards, pianos and organs
Insert a premium compressor with a fairly high amount of compression on Groups 1-5, a lighter amount on Groups 6-7 and medium amount on Groups 8-10. Set the threshold, attack and release so that the compressor doesn't color the sound much.
Using individual channels, pan your lead vocal, bass and kick and snare drum tracks dead center, background vocal tracks at about 10 and 2 o'clock and electric and acoustic guitars, keyboards and percussion instruments hard left and right. Complete the stereo image by placing the toms in a natural from about 9 to 2 o'clock.
To set the volume, solo each group channel one at a time, look at the master channel meter and set the level of each group channel to approximately -20 dB, then unmute all group channels and listen to the mixdown. The levels should be loud enough so that you hear each sound, but make sure that the peaks of the master channel never exceeds 0 dB.
To fine tune the first mixdown, you typically make your bass instruments (Group 2) a louder and higher pitched instruments lower. If a single instrument stands out too much, lower its level until it fits and if an individual instrument sounds buried, raise its level until it sticks out, then drop it back until it fits.
If your mix sounds too thin, increase the level of Groups 2 and 3 and if it sounds too harsh and metallic, decrease the level of high pitched sounds such as high hats, snare drums and crash and ride cymbals. If your mix sounds too nasal, lower the volume of mid-range tracks. You may need to repeat this procedure with short breaks in-between.
After setting the volumes, listen to the master in mono and listen if some tracks sound distorted and that each track can be heard. If so, solo its channel and check and correct its level. If a frequency sounds harsh, find and cut that frequency and without making the mix fall apart.
Now, try to listen carefully if some tracks sound muddy, murky and undefined as if they were "walking on each other". Make the subtle level, equalizer and pan adjustments. To avoid artifacts, you may prefer to work with the MIDI data and replace sound patches and samples. You can also separate the two tracks that "walk on each other" by changing one of the sound samples or sound patches, advancing or delaying one of the tracks and by transposing tracks up or down.
Now listen to the master in stereo and repeat the steps you just performed.
To complete the stereo mixdown, setup at least two reverb on separate stereo effect sends. One should have a large room or hall program and the second can have a small room program. Adjust the large hall program so that it sounds great on background vocals and keyboards and the small room program so that it sounds great on drums and percussion.
Take a break and play a reference track through your monitoring system, at the same level as you are mixing at. Listen closely, how much reverb is used on each instrument? Pay attention to the snare, lead and background vocals, organs and keyboards. You may be surprised at how little reverb most of the sounds have.
Switch to your own mix and add reverb to Group 4 carefully. Experiment with the long and short reverb until the snare drum sounds right without dominating the mix. Repeat this with the Group 5, where you can use the long reverb, and Group 10 where you can try a small amount. On the lead vocal (Group 1) , you may not want any reverb at all although a small amount might help cover up imperfections.
Now setup two delay effects sends, one with a short and another with a long delay, both synced to the tempo and add delay on Group 1, 6, 8 and 9.
After a break, start fresh and listen to your reference tracks again on a low volume. Make sure the door is closed to the room, the lights are dim and your ears are in the sweet spot between the monitors.
Pay special attention to the lead vocal and how the kick and bass work together. In a regular song, the lead vocal should be more prominent, the snare next and then the kick. But for EDM music, the kick and bass can be more prominent.
Ideally set your group channels so that your mixdown peaks just below 0 dB on the master channel, alternatively use your master fader to do so. Next, bring up the monitor volume substantially! This is a very important step when downmixing EDM tracks because you will hear dynamic problems and harsh frequencies.
Most dynamic problems are fixed by adjusting the compressors and the levels of the individual tracks or group channels. Some dynamic problems require separate mid/side processing or MIDI editing.
Obvious stereo field problems are rare, and can be cured relatively easily. They usually occur because of too much 'ping pong' delays or other extreme swirling processing. The problem can usually be solved simply by decreasing the amount of reverb and delay. In some cases, you must ride the reverb and delay, which means that you record it when you change the amounts.
With that, it is time to save mixdown steams. While 44.1 kHz/24 bit is the industry standard, higher resolution is usually better, so you may want to export to 88.2 kHz/24 bit or 96 kHz/24 bit files (or even 32 bit) files. You may also want to export several down mixes, and for example labeling them LEAD VOCAL UP, LEAD VOCAL DN, SNARE UP, SNARE DN, KICK UP, KICK DN and so on with subtle 1-2 dB changes. For best mastering result, save the file without dithering,, and make sure that there is some headroom left, meaning that the file never peaks.