Mastering Explained - Peak vs RMS vs LUFS

INTRO I want to start with a disclaimer that a good mastering engineer is worth their weight in gold. They master music everyday and they are not as close to your music as you are. Having a trusted second set of ears can be invaluable to your music. They the room, the gear, and most of all the experience to make sure your mix is the best it can be before being released to the world. That being said, you do need to understand and even experiment with the mastering process to really improve your own mixes and productions. I am not going to go into the history of mastering here. I will not talk about the loudness wars either. I just want to give you some practical advice about mastering so that you understand what mastering actually does, and use that understanding to make better music! I use the following concepts and tools for every production I do.  

STEP 1 - Metering

Your EARS AND EMOTIONS ARE WHERE YOU START AND END, that being said, you will want to use and become familiar with 3 types of metering before you start mastering. True Peak, RMS (Average), and LUFS (Loudness). This will keep you from over doing compression and limiting, (unless you are intentionally goin for that that crushed sound) …its a real thing.

Peak - Think of peak as what your computer hears. Its a measurement of the loudest energy of your track from moment to moment relative to dbFS Full Scale. digital 0 is the limit of audio anything above that will result in added distortion. Typically this is something you want to avoid.

True Peak takes into account of what levels will be after the digital file is covered to an analog signal. True peak is a safe place to use as your peak meter setting. Aiming for -0.5 True peak should keep you out of trouble with most formats.

RMS is the average level over time…its connected to the way humans hear and perceive the level. Of course your best tools are your ears but depending on your genre and/or your client preferences here are some RMS levels to aim for -12db - 9db is an open dynamic mix - 9-5 Very Loud mix. - 5-3 is Crazy Crushed Loud.  

LUFS - Loudness Unit Full Scale - Basically a more advanced version of RMS. The Current Standard for Digital Streaming (ie Spotify) is -14LUFS integrated meaning the entire loudness over the lengths of the track Put the Level meters at the end of your chain so you can see what you are dealing with as things progress.

Note: if you are receiving a mix that is already LOUD (for example -7RMS and LUFS -12), you should probably ask for a mix without limiters on it because its already crushed. If they can’t or refuse you will need to proceed with caution on those mixes.