Learn about how to create a CD-compatible bounce, why to use a maximizer, and how and why to add dither.
- [Instructor] As you put the finishing touches on your mix, it's time to start thinking about creating the final media. One common asset that you often need to create is a CD compatible stereo bounce. Let's go over some considerations for creating a final bounce for CD. While mixing, you've probably taken steps to keep gain stages in check, this is especially important when using external hardware inserts. Although I haven't addressed it overtly in this course, prevailing wisdom says to keep the meters on the master fader far from clipping, even if that means pulling the levels down across all of your tracks.
If you practice this approach, you'll likely be mixing at lower levels than you ultimately want for the final bounce. To make sure the bounce has adequate levels we can use a maximizer plugin. Here I'll put the maxim plugin on the top insert of my master fader track. Maxim is a dynamics processor that comes with Pro Tools. And the purpose of this and other maximizer plugins is to increase your overall output level while simultaneously preventing clipping at the main outputs.
In this plugin, you can adjust the threshold setting while playing back the session to get a consistently loud output. (upbeat music) As you adjust the threshold, keep an eye on the histogram here, the bars in the histogram will turn red to indicate a reduced dynamic range. (upbeat music) And you generally want to avoid too much of that.
So be sure to keep an eye on this during the loudest portions of the song. (upbeat music) You can also reduce the sealing slider just a little bit to prevent clipping at the master fader. Usually half a DB or so is appropriate to maintain full amplitude while avoiding any potential playback issues. (upbeat music) The other thing we typically need to do is to add a dither plugin to the master fader.
This is important when creating a CD compatible bounce from a high bit depth session. For example when you create a 16 bit bounce for CD from a 24 bit session, Pro Tools performs a bit depths reduction for the bounced file, that means the mix loses the bottom eight bits of dynamic range. Now the bottom eight bits is where all of the low level signals are represented and removing them without using dither can have an audible effect during quiet areas of the mix. Suppose the song ends with a final sustained cord that rings out and gradually decays into silence until the last remnants of the room acoustics and any reverb and delay tails dissolve into the noise floor.
After doing a bit depth reduction you may find that somewhere toward the end of this ring out, the audio suddenly vanishes. That can occur once the signal drops into the bottom eight bits. Dither helps avoid this issue by adding an artificial noise floor. This not only helps mask the dropout, but it actually allows some of the low level signal to remain audible by summing it with low level noise and increasing the overall amplitude in quiet areas.
So whenever you're doing a bit depth reduction, you'll want to add a dither plugin to the master fader. Here I'll choose the power dither plugin which is pretty much the defacto choice for dither today. The power dither plugin provides three options for noise shaping curves, noise shaping type one, type two, and type three. Types two and three have psycho-acoustically optimized noise shaping curves which are good for stereo mixing and are generally appropriate for rock and pop music.
These options essentially make the added noise less noticeable while still being effective for music based material. When you're mixing music with a wide dynamic range, such as classical or orchestral music, select type three for best results. Here I'll choose type two. One more point, you should not add dither in situations where you are not performing a bit depth reduction during the bounce as dither will then be adding unneeded noise. With the processing on the master fader set we can now complete the bounce.
In a case like this, you'll want to set the range for the bounce first in the Edit window by making a timeline or edit selection to avoid the silence before the song starts. And I'll select to the end of this track which is the longest track in the session. Now you always want to check the end of the selection carefully to ensure that you've allowed time for reverbs and delays to decay naturally. When you're ready, select the Bounce to Disk command under the File menu.
And for a CD compatible bounce, be sure to set the bit depth to 16 bit and the sample rate to 44.1 kilohertz. Then select other options as desired. And that's it, by preparing your session properly, your bounced file will be optimized and ready for burning to CD. Remember to use a maximizer on the master fader to optimize levels and add a dither plugin to retain low level audio during a bit depth reduction. Be sure to avoid dither if you're creating a full 24 bit bounce for mastering elsewhere so that you don't add unnecessary noise.
Following these tips will ensure that your final stereo mix reaches its full potential and delivers the impact that you and your clients expect.
- Starting a new session
- Customizing settings
- Optimizing the performance of Pro Tools
- Importing loops and tracks
- Working with meter changes
- Recording multiple takes
- Changing the track timebase
- Editing MIDI clips
- Warping sound and tightening rhythm with Elastic Audio
- Using the Smart Tool
- Color coding tracks
- Editing on the grid
- Working with AudioSuite plug-ins
- Working with sends, plug-ins, and master faders
- Working with track subsets
- Finalizing and exporting media