We have been featuring tips in audio post production in Pro Tools from Marcelo Cyro from the Oscar nominated animation - The Boy And The World and more recently other films. In this article Marcelo is going to explore how to create cinematic subharmonics to really get that LFE channel going.
The LFE channel in a cinema can be used to great effect and the name Low Frequency Effects does suggest what this .1 channel is intended for low frequency effects like rumble, earthquakes, enhanced explosions and so on, to help get the sense of the earth moving. It is NOT a sub for re-routing low frequencies from music etc to get bass extension. The main 5 or 7 channels should be full bandwidth and so there should be no need to use the LFE channel for bass management. It is there for effects. So with that off my chest, over to you Marcelo.
The low end is very important to give power to the sound but how to sound tight and not boomy? One little trick that I learned from my friend and partner at WeCanDo Audio Post is use a Aux Send that only goes to LFE, I prefer not to use the send from within a channel strip in Pro Tools to send audio from that channel to the LFE channel.
As you can see in the screenshot above, in this Aux Send I usually have a high cut in somewhere of 100Hz or lower, a Waves Rbass that give me a solid low end around 40 Hz or something near this! Then the way to make it even thicker is use a compressor that give a nice distortion content. Try something like a like an 1176 or one of my favourites for solid sub is the Softube Summit Audio TLA. This compressor distortion helps to give even more thickness to the low end and also help to sit well in the mix! This technique is very powerful.