So, you’ve been told that studio monitors should not be set too loud, but what does that mean? Sound waves cannot travel through a vacuum, so there is no way they can. Even though there is no escape from the earth, they still vibrate and are affected by air pressure. That’s why it is important to use studio monitors at levels that produce minimal loss of sound when they are being monitored. But how loud should studio monitors be when mixing? To answer that question you have to understand the difference between an isolated sound (with no surround sound effect) and a full band signal.
A full waveform signal has more than one frequency. This is a good thing because it produces a higher quality sound. The problem occurs when one of the frequencies is very strong and other frequencies are not as strong or dominant. A compressor on a mixer will remove the unevenness in the signal so that all sounds within a particular range of frequencies are produced with the same level of quality. It is this quality that allows for the loud sound effect we all associate with a full band signal.
One way of matching the signal level is to use a unity gain (unbalanced) monitor. This is usually set to high gain because it has the maximum allowable signal level. This is the preferred method of monitoring a vocalist and recording an instrumental track, unless of course you are a music producer.
If you are using a compressor to enhance the volume of the vocals, then the unbalanced monitor would be better achieved by using a limiting device (lpadiaphor) such as the Line 6 Podcasters or other models with fast response times. A compressor with a quicker attack time will minimize any drastic changes in signal level after the fact.
Another common problem when tracking a live band is to achieve an appropriate mix using the majority of our available monitoring bandwidth without being able to match the level of output from one speaker to another. In the case of the vocalist, this is often caused by a lack of floor space or a room set up with poor acoustics. In the case of the engineer, it can also be caused by trying to use multiple channels for tracking. Sometimes the engineer has more than one input signal source with different speakers and faders, so that they can monitor the full band. This is called monitors for “many speakers” or “many mix channels”.
The above example underlines why you will need a decent amount of headroom when using studio monitors. Headroom is the difference between levels. Some compressors have automatic gain adjustment, which means they automatically adjust the gain for you, but if you’re using one of those units, you’ll need some form of headroom. Some compressors have “lp” buttons (this is the equivalent of your “lp” fader) which can be used for a short burst of gain.
It goes without saying that in any situation, the dynamic range of any monitor should match the input source. That being said, make sure to get professional advice before setting up your monitors. They may be able to assist you with a good monitoring setup that getting the sound you want from your monitor(s). Monitor mixing is an art, and it takes considerable experience to be able to do it well. If you don’t have the experience, consider hiring someone who does.