The Importance of High Quality Audio for Your Video Production
The importance of high quality audio really can’t be overstated; it’s something we all take for granted whilst simply watching TV, catching a movie or just listening to on our Ipod (other players are available!) Unlike with vision, we don’t ‘notice’ when sound is produced correctly, we just accept it. With vision however, people will say ‘that was shot well’ or ‘well edited…’
Video is all around us. Smart phones, tablets, smart TV’s can all deliver HD video 24/7. We have come to appreciate and expect HD video content, and have become increasingly selective of the quality of video production we’re prepared to sit through. If a production doesn’t hit you with engaging visuals within a few seconds, we switch off and flick to the next channel.
But what about the audio?
Even the most modest device now has the ability to play HD audio. Many media systems are equipped with surround sound with crisply defined high frequencies and trouser flapping bass. So if the audio doesn’t cut it, you’re quickly going to lose your audience.
Thankfully, with the right tools and knowledge, high quality audio can now be captured, edited and mastered with a relatively modest budget.
(For the techies amongst you) the process looks a little like this: As with professionally produced video, work with principle of cr*p in = cr*p out. You should aim to capture your audio with the best microphone possible, in the best acoustic space possible. For voice-overs a vocal booth is a good starting point. An open sounding microphone such as a large diaphragm condenser will capture the most natural sound; this needs to be coupled with a pre-amp that raises the level to the line level required. At Primo Studios we use a Neumann microphone with Apogee pre-amps and digital-audio converters. The apogee has a soft saturation mode that gently limits the signal to capture the hottest signal without nasty clipping. The Team at Three Motion use the industry standard professional AVID compression tool – DIGIRACK
Whilst most film shoots will require the microphone out of shot, when a boom microphone is not possible, a decent ‘lapel’ microphone may be a better option. Even a high quality lapel microphone will capture the sound of the room, so I advise wherever possible choose an acoustically treated recording environment. Once ambience has been captured on a recording it’s very difficult to remove it and although there are many plugins that claim to de-noise they can result in audio artefacts that are less desirable than the original noise you were trying to remove.
If you don’t have the luxury of an acoustically treated room, try to at least steer-clear of reflective surfaces such as floor tiles and flat walls. Heavy fabrics, sofas and deep pile carpets will go some way to absorbing at least high frequency reflections.
So you’ve captured your audio hopefully in a great environment with great gear. You’re going to need to clean it up for maximum impact. I start by rolling off any low frequency signal that doesn’t have any useful content. Low frequency rumble from passing cars etc eats up headroom and results in a muddy mix that lacks clarity. We advise a sharp high pass filter, sweeping up from the lowest available frequency until it starts to sound unnatural and then back it off until it still sounds full without losing any detail.
After cleaning, we can start the process of levelling. Compression and limiting can remove any harsh peaks in level and allow you to increase the overall gain of the signal, effectively raising the volume of quieter audio on the track. Judicious use of compression and limiting will help listeners focus in on some of the quieter sections so that none of your message is lost. Be careful though, over do it and your audio will become monotonously loud and completely loose impact. I advise a gentle compression setting on each individual audio track and then another one on the master buss to ‘glue’ the composite tracks together. Again anything that has a soft saturation mode usually creates the most natural results. Finally I usually limit after the compressor but only by a couple of decibels, again to keep everything sounding natural, clean and open.
This article provides a brief insight into the lengths and techniques that can be deployed in the production of high quality audio. The principles are common place in both commercial music and in professional video production. If your video audio doesn’t cut the mustard, there’s a good chance it hasn’t been treated by a professional.
If one thing’s clear, capturing and producing quality audio is equally as important as the visuals. Whilst a poorly composed shot is unforgiveable, inaudible audio is unforgivable.
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