For audio engineers there is a tool that can be used to limit the dynamic range of an instrument or a piece of audio. This piece of equipment is called a compressor. The compressor is one of the highest and most used tools in studio work, yet it is also one of the hardest pieces of gear to master.
There are different types of compressors that have different uses but it all depends on the context that it is being used in. For example you have the optical, variable — MU, VCA, digital, and so on. They each have their own unique characteristics. Even then you must also know how to use compression properly and when to use it. In some cases you might even need to chain compressors to get a certain outcome.
Let’s say a vocalist has recorded a track and the audio file is very dynamic. You can chain a compressor to help balance the sound and make it more prominent in the mix. One technique that can be used is to take a compressor, preferably one with a fast attack such as a FET style compressor, and give it a fast attack and release to capture the peaks of the vocal. Next, insert another compressor in the chain, preferably a compressor with a bit of a slower attack such as an Optical style compressor (LA-2A is a great opto-compressor). Use it to compress the whole track to achieve consistency. This is a great technique for engineers to use; however as engineers we must remember that there is no secret to obtaining perfect mixing every time. Therefore, you should add this technique to your repertoire, but keep practicing and trying out different methods until you get the best outcome.
For further information on this topic check out http://www.uaudio.com/blog/chaining-1176ln-la2a-compressors. Happy mixing!