Welcome to Voice Over Simplified with me – Katelyn Dawn where we talk about everything voiceover and today we are talking about How To Reduce Your Noise Floor!
So, you want to provide flawless audio to your clients, and that means having a super quiet noise floor! The problem is maybe you don’t understand what a noise floor is, or how to get your noise floor to at least -60dB or quieter! I’ll share what I know and how I was able to achieve a noise floor of around -75dB!
What is a noise floor?
A noise floor is the ambient noise that sneaks into your recordings. Ambient noise includes things like your furnace or AC, space heaters, fans, buzzing from your fridge, or other appliances that are plugged in (even when they are off), traffic from outside, etc. Ambient noise is picked up through your microphone and you want to limit the ambient noise as much as possible.
What is the goal with my noise floor?
The volume of your signal – be it your voice or ambient noise – is measured in decibels or “dB”. The ideal levels when you are recording are as follows:
Voice (Peak Volume Level): -12dB to -6dB
Noise Floor (RMS Volume Level): -60dB or lower
If you are interested in recording audiobooks, for example, your audio will be rejected if you are unable to achieve a -60dB noise floor.
How do I figure out what my noise floor is?
1) To figure out what your noise floor is, you need to record your environment (no talking just “silence”).
2) Be sure that you are recording your environment at the same volume (or gain) level on your interface that you use to achieve your -12dB to -6dB peak levels when you are talking.
3) When you listen back to your recorded “silence”, you can then see what your noise floor is doing.
Just remember that a person who speaks quietly and has a peak of -12, and a person who speaks loudly and has a peak of -12db will have a different noise floor measurement because the interface gain input will be different. This is why it is important to speak louder and get as close to the mic as possible without compromising your sound. These are important choices to make to increase your signal to noise ratio.
Where do I find my noise floor in my DAW?
There are two types of measuring volume: Peak volume levels, and RMS volume levels. Now, I’m not an audio engineer but have consulted my uncle Kirk who is an audio engineer (and a genius I think).
Your peak volume levels are the highest points in your waveform that your audio will ever reach. These are the volume levels that you never want to exceed -6dB when recording.
RMS (Root Mean Square) volume levels take the average volume throughout your recording and this is the measurement you do not want to exceed -60dB when you are not talking.
Each DAW (Digital Audio Workspace) is different, but I use Logic Pro, and you can find this information in your MultiMeter found in Effects > Metering > MultiMeter. Here you can adjust the graph to show a level meter below -60dB.
If your RMS signal is showing -60dB that is great. If not then you will need to fix this…
How To Get Rid Of Ambient Noise Sources:
1) Remove obvious noisemakers.
In order to remove or mask the ambient noise that is coming through your microphone, you need to start with obvious things like turning off appliances that create noise, if there are items that are plugged in but not being used just unplug them because they can create a buzzing noise. Close all your doors and ask your family to be quiet. Now test your noise floor again.
1) Treat your space with sound-absorbing materials
The next thing that is super important is treating your space with sound-absorbing panels, sound-absorbing studio blankets from somewhere like Vocal Booth To Go which you can use inside your vocal booth, or as a sound-absorbing treatment on your windows and doors.
You can create a vocal booth for a couple hundred bucks!
These are the types of things that are paramount to reducing your noise floor and creating super clean audio.
Once you do each of these things, test your noise floor again and see how much each thing improves it.
Does my Microphone make a difference with my noise floor?
A high-quality large-diaphragm condenser microphone will amplify your noise floor. You want to find a large-diaphragm condenser microphone that has a cardioid polar pattern.
What is a cardioid polar pattern?
A cardioid polar pattern will pick up audio that is directly in front of the microphone. You don’t want a microphone that picks up audio from every direction (noise floor hell). With this in mind, you also want to point your microphone away from windows and doors and anything that will make noise. My microphone is facing the opposite direction from my window and aimed towards my closet (even though it is in my vocal booth).
Where should I be in relation to the microphone to reduce noise?
You want to be in front of your microphone where it will be picking up your voice, and you want to be about 6-8” from your microphone.
Get as close as you can to get the “hottest” signal, but not so close that mouth-noise and plosives become an issue. Speak at a nice volume.
You do not want to be recording with your interface set at a low volume because you will have to increase the levels afterward in your DAW which will bring up your noise floor.
Your Last Resort For Dealing with Ambient Noise: Audio Effects
While you need to do everything you can to reduce your noise levels while you are recording, sometimes audio effects can help. These are the do’s and don’ts with audio effects:
DO: use an EQ roll off
A lot of ambient noise can be found in your super-low audio frequencies below 75kHz.
The human voice lies anywhere between 85kHz for the bassy males to 255kHz for the ladies.
Open up your EQ settings and make a “low pass filter” which makes anything less than say 75kHz go away.
Here are the settings I use in my EQ filter roll-off, or my EQ “low pass filter”.
You will want to adjust this if you have a super low bassy male voice but play around with it. This is a great way to clean up some of your ambient noise without negatively affecting the rest of your audio frequencies.
DO: use a noise gate IF you know how and when to use it.
A noise gate reduces the volume of your signal when you want it to engage. Say your noise floor is -60dB, you could make a setting that says whenever my signal reaches -55dB (during silent periods), reduce the volume by 20dB. But you want to adjust the attack, hold and release parameters so it sounds natural.
A noise gate is kind of like using salt when you are baking cookies. A pinch of salt brings out the sweetness and flavor, but too much and it’s gross.
You want to use a noise gate SUBTLY because it is super easy to pick up if it is too aggressive – especially where breaths are. Do NOT use a noise gate unless you understand how to use it.
DON’T: Ever use a noise reduction tool. Ever guys – seriously.
Avoid it like the plague. This is a tool you use if you are given crap audio to begin with and you need to try and restore it as best you can with a tool like izotope ozone or something.
Never use it in your recordings. Ever. Noise reduction affects your entire recording. If you feel the need to use a noise reduction effect – dont, and go back to treating the ambient noise in your space.
I hope this helps make sense of what a noise floor is, how to treat your space to achieve a low noise floor, and a brief understanding of the appropriate effects you can use in editing your audio to assist in achieving the lowest possible noise floor that you can!
Thanks for reading and happy recording!