How to Prepare Your Mixes for Streaming, Vinyl & CD mastering
1. What file format do we need to supply for mastering?
Whether your mixes are being mastered for streaming, CD or vinyl release, 24 bit WAV files are the standard format to present at mastering. (32 bit is also acceptable) Sampling rates from 44.1kHz through to 96kHz are all perfectly acceptable. If possible, we also like the mixes to be labeled in the following manner – ‘01. This is it 24/48’. This tells us that the song called, ‘This is it’, is the first track on the album. It also lets us know that the bit resolution is 24 bit and that the sampling rate used is 48kHz.
2. Listen Carefully to Your Final Bounces
This may sound like an obvious point to make, however faulty bounces are the number one reason for hick ups and delays at the mastering stage. Don’t assume that your humble PC is going to output your 132 track mix perfectly every time. Always listen to your final mixes from the beginning to the end before sending it to mastering. Make sure all tracks are playing correctly, and that there are no clicks, pops or mutes in the audio. This is especially important if there is heavy use of plug-ins on the mix.
3. Do I Normalize my mixes?
Don’t use any kind of normalizing on your mix-down. It’s simply not necessary, and some applications can actually degrade the audio with this process. A mastering engineer will never complain about to much headroom.
4. Do I need to limit or compress the stereo mix before mastering?
Compression on individual channels is pretty much essential in modern music production, however avoid placing a limiter or ‘finalizer’ plug in on the stereo buss. Don’t be concerned if your mixes are not peaking at zero or sound quieter than commercial reference tracks you may be listening to. Your mastering engineer will no doubt have access to some of the world’s best compressors on hand, so he or she will take care of the final volume at the appropriate stage during mastering. Some creative compression on the stereo buss is fine, just don’t use compression for the sake of raising the overall level of the track. If you’ve been mixing into compression and feel it has become an integral part of the mix, it’s best to send 2 prints of the final mix. One with and without the stereo buss effects.
The waveform below is an example of a mix with little, to no headroom. Not an ideal mix to be presenting the mastering engineer with. Mixes like this have so little room to work with, it simply means that the mastering engineer cannot work as effectively on the mix.
Try and aim for a mix that has at least 5-6 dBs of headroom. An RMS (or average level) of – 15RMS is a great volume to aim for in the final mix. Most level meters in modern recording software will have comprehensive meters to show you RMS levels, but if yours doesn’t, there are plenty of free metering plug-ins that are extremely useful.