For example, I produced a track, then exported an mp3 or wav, but it is in no way comparable to the quality of the clips on YouTube.
Do the producers pass the track through some kind of equipment or what? In their clips there is such depth, etc.
I saw music on YouTube written in MilkyTracker and the audio in this video sounds awesome! But if I export audio from MilkyTracker, it will sound in no way comparable to that.
MilkyTracker is just a tool, and like any tool, the quality of the tool is less important than the skill and knowledge of the person using it. You could give a carpenter terrible, rusty old tools and they would make something far better than I could even with the very best tools available.
These things take a lot of practice to get good at, but everyone starts out not knowing what they're doing, and it's incredibly satisfying to see yourself improve over time!
There's a lot that goes into a good sounding track. It's a chain of things all the way from the input sound source to the output track. And like any chain, it's overall quality is limited by its weakest link.
The quality of the singer/instrument/thing-being-sampled is very important. Then there's the room it's recorded in. Does it add color, or is a neutral recording room that allows color to be added during the mix? What about the equipment used to record the sound? This means the choice of mic, the position of the mic, EQ, compression, and so on.
The mix itself is super important. A talented mix engineer adds so much to the recorded material. They're like the editor of a film. They can work magic, however what they can ultimately accomplish is limited by the quality of the recorded tracks or samples that they're working with.
Mastering is also important, although really only polishes a well crafted track, it's not going to create something great out of something mediocre.
The lovely thing is that everything you need these days can be obtained for far less than used to be the case. The very best equipment is obscenely expensive, but you can get good stuff at a fraction of the price. And in the right hands, you can get professional sounding results with (reasonably) inexpensive equipment.
Quick answer - try running your output through a compressor.
Long answer - work on your composing, arranging and recording skills. Get years of experience. Then try running your output through a compressor.
Besides mastering and other thing related to creating the source audio, you'll also want to make sure that you aren't applying lossy compression to your audio before it gets uploaded - this won't make a big difference in most cases but can't hurt to get in the habit of. Whatever video and audio container format you're using to upload, you should make sure the audio track is stored as PCM data or something lossless - that way, when it's uploaded to YouTube, it'll only ever get compressed lossily once, by YouTube. That way, anyone hearing the audio on YouTube will only hear something that's been lossily compressed one time.
Personally I like to use .mkv containers - there are several programs out there, like MKVMerge, that let you drag and drop files (such as .wav files) straight into an MKV container, so that you know no compression is going on behind the scenes. I typically render my video out with lossy compression, then drop the video into a .mkv, then a .wav, then upload the .mkv. It works perfectly on YouTube.
