Quick Audio Mastering with Reaper

audio statistics

audio statistics

STEP10.) With the audio statistics plug-in added; play the song from start to finish. The plug-in will automatically gather audio statistics data. After completing the statistics at the end of the song; take the average of the RMS total loudness values (L and R). You will need these data to set your limiter. After taking the average, remove the audio statistics plug-in from your master track effects because it’s not needed anymore.

RMS level audio stat

RMS level audio stat

STEP11.) Supposing you target an after-limiter average loudness of -16dB; this varies depending on your loudness expectations. In really loud masters, this can be -12dB and beyond. Take note that as you increase loudness, the dynamics can be affected so set a realistic loudness target that won’t damage the original mix dynamics. The rough formula for limiter threshold would be:

Threshold = RMS total values (average of L&R) + 16dB.

Therefore the threshold settings would be:

Threshold = -27.18dB + 16dB = -11dB

Add a limiter plug-in to your mastering track after EQ; and set the threshold settings. If there is an “out of ceiling” setting (such as Waves L1); set it at -0.3 to provide a little headroom.

Limiter in Reaper

Limiter in Reaper

As a golden rule, make sure you preserved the dynamics in your recordings. Read this tutorial on how to make radio friendly mixes.

STEP12.) Play the audio in Reaper. Monitor carefully for the presence of distortion, pumping, clipping and severe loss of dynamics in your work. Re-adjust your limiter or EQ settings if necessary. If all are OK, select the final section of your mastered audio. This will highlight only the important sections (see the white background sections on the screenshot below).

Sections for mixdown

Sections for mixdown

STEP13.) If all are set and the sound of your mix down is now big and broadcast ready; render the results by doing a high quality mixdown in Reaper. Take note of the following pointers:

a.) The sample rate should be the same as your source audio (mix down).
b.) The bit depth should still be 24-bits.
c.) When closing your mastering project, do not forget to save it always.
d.) You can re-measure the audio statistics after mixdown using the JS: schwa/audio_statistics plug-in , you have at least attained your target loudness which is near -16dB after limiter.

attained specified volume

attained specified volume

The resulting 24-bit audio is the final master, keep this as a backup. This is the source file for your distribution either in CD-audio or MP3.

Some tips on distribution

STEP14.)If you want to distribute your masters as MP3, you can read this tutorial on mp3 encoding with dithering and sample rate conversion. This is where you will implement appropriate sample rate conversion or dithering. As a rule of thumb, sample rate conversion should be done before dithering.

encoding a wav to mp3

encoding a wav to mp3

If you want to distribute your masters in CD audio format, unfortunately Reaper is not capable to create Red Book CD or burn audio to a CD. In this case, you need red book CD authoring software such as Sony CD architect. For more details, you can read this tutorial on red book CD audio standard.

Content last updated on June 14, 2012

  • Alphy James Sabdao Inosanto

    This was very helpful! Thanks, man!