Audio Basics - Quiet audio recording
Hello all, OK so it is not VFX but as we all know sound will make or break a video/film. I am no expert, in fact I am 100% novice at audio, learning as I go. I wanted to share a tip that I learnt this weekend.
I recorded some speech using a mic at my desk, the end result was a quality recording (in my opinion) that lacked volume, when I transferred it to my phone and played it back it was barely audible. Therefore, I did a bit of googling to work out how when you switch on the radio or the telly most stuff sounds the same across the channels. How this works I am not very clear on, but what I did find out was the following.
When you view your recording in say Audacity you see a wave form, the peaks represent the audio signal, if your waveform is small your audio will be quite and if it is large it will be loud. To large and you get popping or bits blown out, basically not a good recording and the audio is lost. So how did I fix it? I used two tools in Audacity. First I ‘Normalised’ it, this with default settings increased the volume of the sample a fair bit and on its own would probable do. However, I wanted it a bit louder so I then used ‘Amplify’ which I experimented with +DBs. Basically to much and you loose the top end peaks (blown out), so I started at +5.0 which was too much and settled for +2.5 which was acceptable. Once I saved it out and transferred to my phone, it played back at an acceptable level.
If someone knows what this process is called (Normalisation?) then please share.