More and more clients are coming to us wanting Video Description mixed for 5.1 surround sound, so we enlisted CaptionMax Video Describer Caiti Laszewski to explain the ins and outs of mixing for 5.1.
What is a 5.1 mix?
A 5.1 surround mix is an audio mix made of six sound sources assigned to a field of left, right, center, left surround, right surround, and low frequency effects, or LFE, channels. The LFE channel, containing only the lowest frequencies, is typically played through a subwoofer and is represented by the .1. The remaining channels can contain a full range of frequencies, and they make up the five main channels of the mix. The 5.1 mix is meant to envelop the viewer with the program’s soundtrack, bringing the theatrical surround sound experience home.
How we mix to 5.1
For mono, stereo, and 5.1 mixing, we take the client’s completed mix of program audio and combine it with our descriptive audio track. We strategically alter the volume of the client mixes where our description comes in to allow the descriptive audio to be understood as clearly as possible without covering the essential elements of the program audio.
We complete all of our 5.1 mixes using Pro Tools software in a surround monitoring suite. This allows us the most flexibility in description timing and volume when combining our audio with the client’s mix, resulting in the best possible finished product. The granular control Pro Tools affords us allows our description to come through as clearly as possible, even when it covers extended sound effects (like gunfire or prolonged explosions) or stretches of subtitled dialogue.
Differences between a 5.1 mix and a mono or stereo mix
In a traditional mono or stereo mix, dialogue, music, and sound effects are mixed together and audible on all channels. This means that the volume of the entire mix needs to be lowered to allow description to be heard clearly.
A 5.1 mix sends all dialogue (including descriptive audio) to the center channel, allowing music and sound effects to come through from the other channels. In a surround mix, the volume of any program content in the center channel needs to be lowered so description can pass and be easily understood. Often, the left and right channels need a slight reduction in volume to ensure description can pass clearly over any music or effects on those channels.
Benefits of a 5.1 mix
Mixing in 5.1 gives us the flexibility to decide when, how much, and on which channels to lower the volume of program audio. Occasionally, the center channel is the only channel requiring volume alteration, and all the other channels can be left alone without a negative impact on the clarity of descriptive audio. In a mono or stereo mix, lowering the volume of the mix as a whole means covering music and effects. In a 5.1 mix, more of these secondary elements can be heard, helping our description blend with program audio. It’s a more labor-intensive process, but it’s worth the work to help the consumer have a more seamless experience of the finalized program.