In live music recording less emphasis is put on the mixing of volume levels nd EQing. Those things are largely taken care of later, after everything is recorded.
In electronic and hiphop music a lot of mixing and EQing is done during the composition phase itself. Because in some essence, the "live instruments" have already been recorded (if you're using samples) and when you're putting together a track with samples or synths, your job includes mixing, balancing and EQ.
So you've already answered your own question. Yes, they do mixing at the composition stage. So for you to get good at it, you must also learn how to EQ, balance the volume levels of synths/instruments, pan and compress. But if I were you, I wouldn't mess with it too much in FL.
Make a "rough draft" as a painter would outlining general shapes in a painting. Focus on the actual composition, you'll concentrate on other details later. Besides, there are better tools for mixing actual wave tracks such as Audition, Audacity, etc. In FL, after a certain point, you'd be just wasting time.
FL is mainly a tool for composition, a sequencer.
Multi track recorders are mainly for mixing.
There are two places where the overall output level (volume) of FL Studio can be adjusted -
Main volume fader.
Master Mixer track fader (14 bottom of page), see the 'Mixer reference diagram' below.
The Main volume fader should be left at the default position (Right-click and select 'Reset') and the Master mixer track fader used for overall level adjustments. The following discussion assumes the Main volume fader is in the default position.
How to adjust levels of the final mix
FL studio has a Main volume, in the menu bar AND a Master Track Volume (14). To ensure the Master mixer track level is an accurate reflection of the final output:
Make sure the Main volume is at the default level (Right-click and select 'Reset'). It's probably a good idea to get out of the habit of even touching this volume slider, its main purpose is to make sure a master volume control is always available (when the mixer is hidden) and some audio emergency crops up.
Adjust Mixer Track Faders and/or Channel volume knobs to obtain the relative instrument levels you desire in the mix.
Use the Master Track fader (left most track in the Mixer, 14) to adjust the final level. Consider also, placing Fruity Limiter in the last FX bank of the master track. Limiting is a form of automatic peak volume control.
Following the above steps will ensure the Master track peak meter (5 & 11) and the Main volume meter, in the menu bar, display the same peak levels. Red/Orange peaks (over 0 dB) will indicate clipping in the final output or rendered mix, as depicted below.
Sampler Channels vs Audio Clips
If you are paying particularly close (and possibly unhealthy) attention to the output levels of Sampler Channels, you may notice they are a few dB down on their recorded level. There are three reasons for this:
Sampler Channels load at a default 55% volume, about -5.2 dB. This 'feature' is to prevent clipping when several Channel Samplers are used together and also to allow some extra headroom for note/step velocity modulation. The assumption is that Channel Samplers will be used as 'instruments' and so you will be playing (see the next point) and mixing them to sound right 'in the mix'. If a Channel Sampler is too quiet, turn it up.
Sampler Channels respond to note velocity. The default note velocity in FL Studio is 100 (MIDI = 0 to 127). If a sample is too quiet you can also play it louder.
Sampler Channels respond to the default Circular Panning Law. This reduces the sample gain by -3 dB at center pan, tapering to 0 dB at the extreme L/R pan positions.
So together the default load state for a Channel Sampler can be about 8.2 dB lower than the samples recorded level. If you absolutely need a sample to render at its recorded level, load it as an Audio Clip by dropping your samples on the Playlist (these default to 100% volume, 0 dB). Finally, make sure the Master and Main volumes (described above) are set to 0 dB and don't forget the effect of note velocity on playback level.
Using FL Studio Peak Meters
Often when mixing, your goal is to get the peaks of the loudest sections of the mix close to the maximum possible level, 0 dB, without clipping, going over 0 dB. Clipping happens when a sound wave carried inside audio equipment (analog or digital) becomes louder than the maximum volume that can be reproduced. When audio is clipped its waveform looks like the tips of the peaks have been 'clipped' off, as shown in the picture of the Main peak meter below (left). While occasional transient clipping incidents are not usually a problem, if clipping is pushed too far your audio will distort and crackle. Once a saved (rendered) audio file is badly clipped, there is no way to fix the problem (although the Edison Noise Removal Tool does have a Declipper Function that can rectify mild clipping issues).
This can easily become very frustrating while mixing and very often leaving your mixes sounding “worse” than the original beat!
I’ve wrecked a lot of beats while trying to mix. Mixing doesn’t come easy; it really does come from hands-on practice. If you aren’t practicing, you can guarantee you’re not going to get better!
Instead of making a beat, take time out to learn mixing. The more things you can know as a beatmaker/producer, the more valuable you will be.
By that I mean, if you know how to make a beat, mix, and master.. well, that’s 3 jobs you have! In the music industry, these are 3 individual jobs that take place. So the more you can learn and conquer, the more ahead of the game you are, the more you understand, and the more money you can save in the end!
Have you ever attempted mixing vocals? This starts to make your beat now “a song”. I feel when vocals come in to play, there’s a lot more room for error, as now you have to try to get that vocal to sit nice in the mix! (But practice makes you better right!)
Take advantage of that LOW CUT / HIGH PASS FILTER, this is very handy to clean up mixes, as there is unnecessary bass in a lot of sounds and instruments! — Again, the rule of thumb is to go until you hear the filter effecting the sound, then gently back off until it’s sounding how it was.
Many times even if the sound isn’t sounding normal, and is sounding a bit thin and weak because you’ve gone too far with your high pass filter, it can make the sound cut through your mix even more, so sometimes doing the cut while your beat is playing is a good technique as well! (As this is how the sound is going to be played; with the beat, not solo’d right? ;) ).