GOOD MONITORS ARE EXTREMELY IMPORTANT.
Video productions monitor using screens. Audio productions monitor using speakers that are driven by amplifiers.
Every decision made in a musical production (not only regarding sounds but also arrangements and even performances) is based on what everyone is HEARING. For example, if you are recording a bass sound and your monitors sound thin, you may mistakenly believe that the bass sound itself is thin and compensate by adding more bottom. Then when you hear the same sound in a different location you may find that the sound has too much bottom and is muddy.
Likewise, if a singer is performing and cannot hear the proper blend of music and their voice, they will not be able to perform as comfortably and to their fullest potential.
As stated above, every decision made in a musical production will be based on what people HEAR. What people hear can be affected by many things, including speaker type and condition, amplifier type and condition, headphone type and condition, quality of wire and soldering, ear wax, sinus congestion due to colds or allergies, ear fatigue, and the changing acoustics as people move around in the room. Even air pressure (based on weather and altitude) can affect how things sound.
Going back to the video comparison, you would not crank up the amount of “red” on the screen before you adjusted the color of the video itself. Video monitors can be set differently in a variety of ways, and screens display colors differently as they age. Colors on a screen can even look different if viewed in a dark rather than a well-lit room. And looking at the sun for a few seconds makes it difficult to properly see and judge any image (much like the ear fatigue from listening to very loud music makes it difficult to properly hear and judge any sound).
Similarly, in audio VOLUME is very important. Human sensitivity to frequencies (our ability to hear bass, midrange and treble) is different depending on the VOLUME of what we are listening to (thanks Fletcher & Munson). When we listen quietly, we hear frequencies less evenly. When we listen loudly, we fatigue our ears and the speakers.
Another variable that can change how you hear something is perspective (actually, perspective affects how you JUDGE what you hear). Listening to material that has extra bass or treble will affect how you perceive and even judge the next thing you hear. If you listen to rap and reggae all day and then try to mix a punk rock song, you may judge that the kick and bass sounds need to have more bottom when they may actually be appropriate for the musical style.
Let’s drop most of the variables.
First of all, your wiring should be solid (a bad solder joint can affect sound), your patchbay should be clean, and all of the knobs and faders you are going through should be well maintained.
A good AMP is as important as good speakers (BOTH are important so do not try to skimp on one or the other). The amp should be powerful enough that you will not blow your speakers due to distortion (distortion can flatten a sine wave to a square wave, which can blow speakers because the cone will be jumping rather than smoothly moving – more on this later).
The combination of AMP and SPEAKERS is crucial. DIFFERENT SPEAKERS WILL SOUND DIFFERENTLY. DIFFERENT AMPS WILL SOUND DIFFERENTLY. THEREFORE THE SOUND YOU HEAR WILL BE BASED ON A COMBINATION OF THE AMP AND SPEAKERS YOU USE.
I have often mixed different amps with different speakers, in order to get a sound that I thought would translate properly to other sound systems.
Some companies (such as Genelec) make speakers with built in amplifiers that have been designed together so the combination of amp and speaker will always be consistent.
Finally, be aware of how your room acoustics will affect the sound of your monitors. Mind parallel surfaces that can make sound bounce back and forth, and be careful of high frequencies bouncing off of the glass to the studio.
Oh, and don’t forget to listen in mono now and then.
I personally like to monitor through ProAc speakers (with a Bryston 4B amp), Yamaha NS-10s, Genelec 1031s, and a bunch of small boom boxes (Sony, Panasonic, etc). I sometimes used Auratones but prefer the small speaker in Studer 2 tracks. I hardly EVER listen to “big” speakers as I get great bottom and depth from the ProAcs. However, I do listen to “small” speakers frequently, and even listen from another room for final decisions.
I used to have a cheap stereo in college that sounded terrible, but in ways I was used to. When I started mixing, sometimes I would hear problems on that cheap stereo that I did not notice when listening on “nice” speakers. Now I try to listen to as many speakers as possible in the hopes that one pair will show me something wrong that I did not notice on “nice” speakers. I even take copies of what I am doing to stereo stores and listen in each system and boom box until I find something that needs attention.
The people who hear your mixes do NOT usually listen on “nice” systems, but rather on overly-hyped systems made for volume rather than even sound. They even listen with stereo speakers split in different rooms (right in one room, left in another) and many people share ear buds with friends (each hearing only one side of the music). My parents had a stereo with a broken left speaker that they never fixed. Imagine my surprise when I finally heard BOTH sides of Beatles songs!
Does that mean we back off from making things sound as good as we can? Does that mean that we should avoid extreme stereo so the people who share earbuds will hear the correct parts? Of course not.
A GOOD MIX SHOULD "FEEL" RIGHT ON ANY SET OF SPEAKERS. There are exceptions (such as reggae sounding right on a speaker without any bottom) but for the most part, your goal should be something that feels right no matter where you hear it.
STORY TIME: ONCE upon a time, I was mixing a TV theme song recorded by a very famous musician and produced by another very famous musician. During the song there was a break with the following rhythm: "da da da-da da da da-da". I was being slick (it was for stereo cable TV) so I panned each part of the rhythm from left to right. UNFORTUNATELY when they were creating graphics for the intro the stereo in the graphics suite had only had ONE working speaker and so they only heard HALF of the rhythmic part. They created the graphic that hit along with the half of a part, and when it was shown in stereo with the FULL part it looked stupid. We had to then go back and change the SONG to fit the wrong graphics that were made (it was the cheaper fix).