What goes on after all the parts are recorded?
Well- funny you should ask.
First there're all the mixes. This is where you 'balance' all the sounds against eachother. Not to make sure they're all the same volume, but to make sure they sit in the song where they should be. You don't want an electric guitar that is way louder than every other sound. You want it to sound like an electric guitar playing with all the other instruments.
Now some things are nearly always a bit louder. Vocals, snare drum. Besides that, the mix can really change how a song feels and sounds once it's done.
So there's lots of listening. On all sorts of different devices, speakers, stereos. For me this means my main set up in the studio. Then my car. I check a lot of mixes in the car. I have a really good stereo system in my living room. That one matters too. Also I have a PA speaker set up in my barn. The car gets two kinds of checks. A CD in the radio and streaming from my phone. The last few are no less important. Headphones. I have a high end set I use for recording and ear buds. Finally, I just play it through my phone with no headphones.
The idea is to have all the parts I se expertly mixed audible on ALL of the different places I listen to them. If not, back to the mix.
Mixing is also kind of funny in that sometimes to make something sound louder, you do it by turning stuff DOWN. I know! Weird right?
This is really the most important stage in the finishing of a record. If you can't hear the song the way you want in your mix, well, nothing can fix it once you press it. So lots of time on this part.
The thing I've learned over the years is to NOT listen to the song like a fan. It's a different kind of listening when I mix. It's critical yes, but more focused on 'what serves the song'. How do the different parts interact? How do they sound together?
The other important thing is to take breaks. This is because of a few things.
One- My ears get 'tired'. Too many passes of songs and I'm not sure if I'm hearing problems or just making them up
Two- getting 'used' to a certain idea. For example let's say 2 songs have similar instrumentation, tempo, feel. They may need radically different things in a mix, but if I work on them too long together I might start reflexively doing similar mix tricks to both and end up with a mess
Three-- sick of it all! Some songs mix easily. Some well...don't. I could listen to the same song or even the same section of a song multiple songs. And start to kind of hate it and my existence and throw out the hard drive and go work at McDonalds
So I am mixing. Listening. Taking breaks. Listening more. Mixing again if I need to.
As of today I THINK I'm happy with ALL of the songs.
One more day of listening checks and I'll know.