Once you obtain a result that you think is good, your work is not over yet. You must also take the time to listen to your song on all types of listening devices in order to check that it sounds well everywhere.
Why? Because all devices do not reproduce sound the same way, et the more devices you can lay a hand on, the more you can come to a compromise, a sort of "average rendering" to adjust your mix. If the cymbals in your song are too loud and make your ears bleed, it means that something definitely needs to be done. But if they sound a bit too loud on a system, and a bit too low on another system, but sound well on your monitoring speakers, then it is wise to leave them as they are and hope your listeners will be using a neutral-sounding device.
Here are a few listening devices you could use:
- Monitoring speakers
- Headset (open, semi-open, closed, basic headphones, in-ear headphones, etc.)
- Stereo system speakers
- Computer multimedia speakers
- Television set
- Car speakers (many people listen to music in their car)
It could also be interesting to listen:
- From another room: you can spot things from a distance that you wouldn't necessarily notice when standing in front of your speakers, right in the middle of the stereo field. This can lead to making adjustments or improvements.
- At different volumes: it is proven that lower frequencies are perceived differently depending on the listening volume. In order to avoid listening fatigue (and protect your ears), you should mix at a reasonable, comfortable volume. Not too loud! But at lower volumes, low frequencies don't stand out as much and you may tend to add too much of them to compensate. Thus, when listening to the final result at higher volumes (because music sounds so good when you crank it up!), you will find out there's way too much low frequencies. Check it out.
Each time you use a different kind of audio device, various aspects will stand out. On a good stereo, everything should be harmonious and balanced, in a car, bass sounds are usually tiny and if you listen from the next room, it will also sound different. All this will help you to find the right balance between instruments and that would be a mistake to listen to your song from only one audio device, no matter how good it can be.
Listen, but also take breaks, it's indispensable. Ears tend to get tired quickly and get used to what they hear. If you listen to a section of your song that is faulty for three hours in a row, you will end up not being able to hear the flaws anymore and thus... not correcting them. Also, your appreciation of an issue will change over time and you will modify things that you should not have (or did not wish to) modify in the first place, or at least not that way.
When you have spent a few hours mixing a song, don't hesitate to leave it aside for a couple of days. Listen to other stuff, forget about your song completely. And then, listen to it again with fresh ears... its flaws and qualities will jump right to your face! After two days, you will be objective again, and that's what you need to achieve a good mix. But as you may know, the ear will get used to what it listens very rapidly, so what strikes you at first as a problem will soon again sound normal to you. In order to avoid that, write down what you thought as negative in clear terms: the left guitar is too loud, the guitar on the right is too dull, the kick sounds too dry, there is too much reverb in the vocals, etc.
Write down and fix, then start this process again... Give it some time, listen again with fresh ears until you are satisfied with the result. This is of course time-consuming, but it's worth it. We all want to make it final, to listen to the finished song, to have people listen to it. But it's even more satisfying if you are really and thoroughly proud of your song, rather than letting your friends listen to a song that you know has some problems you were too lazy to fix, don't you think?
Your ears are not always the best judges out there! How can you be sure that what you hear is really good? How to remain objective with a personal creation? Even though you are your first audience (obviously!), even if your song must please you first, you still have one ordeal to overcome: have someone else listen to your work...
But don't take any chances, because you may not like the opinion you are going to get. So don't have anyone listen to your work before you have made enough progress. You will waste your time and your listener's if you insist on having him/her listen to some unfinished, half-intelligible stuff. If you are aware that the time has not yet come, then why rush things?
When you ask for someone's opinion, tell them exactly what you expect. As long as you don't see your work as complete, ask for an objective, technical opinion. Is the sound ok, not too bright, not too dull, are the lyrics understandable, do the drums sound fine, does this part provoke the expected feeling (strength, peace...)? Later, when you consider your song as finished, you can ask the ultimate question: "Do you like it?"
You should know one thing: everybody feels differently, they listen to the same song and hear different things. If you ask 10 persons their opinion, you are going to get 10 different answers, very often conflicting. Kevin loves the sound of the guitar, but Jane hates it because she thinks it's too aggressive. On the other hand, they both agree that the vocals are great, while John thinks they lack energy, and they should calm down more before the guitar solo...
In the end, you will take the decisions, but other people's opinions will necessarily have some influence on you. The purpose of music is of course about enjoying it, but also about sharing it. So if you are the only one to like what you do, that's fine, but it's a bit frustrating. And you will undoubtfully appreciate that your friends, relatives or colleagues tell you how great they think your song is.