This week we have been focusing on noise gates and vocal recording technique.
Noise gating is taking a sound and isolating it to get the sound we want. For example if we recorded a drum set and we listened to the top snare dynamic microphone. We hear the snare with a lot of background noise such as cymbals etc. Gating allows us to remove the background, but keep the snare sound on a track. the gate removes low volume signals from the track, so when setting up the gate you set a threshold, which is the volume level, so when signal falls below the threshold level the the gate closes and stops the noise coming though. This needs to be set as low as possible as we want to keep the main signal. If you set the threshold too high you will only hear the attack of what is being played e.g. the snare attack. This brings me to discussing attack time. Attack time is the time it takes for the gate to open when the signal exceeds the threshold level. Fast attack time like can create distortion caused by low frequencies. If the attack time is too long the attack/ percussive parts will be removed. That is why when gating drums a fast time is used, especially for a snare drum because of its impact. If you do not have a fast time it will not sound like a drum, but not too fast as it can cause clicks or distort the signal. The attack is how fast the gate is going to open. The last two parameters of a noise gate are the hold and release, these make the sound sound less robotic. The hold is how long is the gate going to stay open after the signal level has fallen below the threshold and the release is the opposite to attack and that is how fast does the gate close. When the release time is set fast it will sound robotic, however too slow the background will bleed into the signal.
https://www.youtube.com/watch?v=ON6LKV23uiE – Reference (Good explanation of what a gate is)
Another technique used to remove noise is a function within pro tools called strip silence. This function will detect audio when aset threshold has been made a remove strips of background unwanted noise.
Vocal recording technique:
After gating we started to record vocals. Vocals are usually recorded in a vocal booth, which is a small room, so the environment is dead so that later reverb can be add artificially in the mix. Sound reflections are kept away and there is usually acoustic treatment to achieve this. Most vocals are recorded with condensor microphones because they have high sensitivity and a big frequency response, however some singers also use dynamic microphones such as rock vocalists this has a hard hitting sound. The polar pattern is cardioid, as it rejects off axis sounds. Also typically used in a studio are pop sheilds these stop ‘P’ and ‘B’ sounds cause by blasts of air. This shield usually positioned about 150mm to 300mm from the mouth. The microphone we used in session was the Neumann TLM 103 | condenser | cardioid.
The last thing we looked at in this session was a quick look at the stereo technique AB. two Onmidirectional mics.