Unless you are a bit of an audio geek, you have probably never really sat down and studied your microphone’s specifications. In fact, most people simply buy a microphone because either it’s cheap, the guy at the store said it was a good one, or they read a few reviews on the internet for a good sounding microphone. Rarely do they actually consider the specifications and what they mean.
We did the same until we really got serious about our microphone choices and it took us a long time to wade through technical jargon spouted by the audio experts. It’s actually not that easy to find information about microphones that is spelled out in layman’s terms so this is our attempt below. Honestly, there is a ton of information on the net if you want to really get into the nitty gritty and hone in on each and every detail, but we figure most people here just want to spend the majority of their time making good quality ASMR videos and not studying the technical aspects of it all. So this is a easy to read guide just to help you feel confident about what you are buying when you go searching for a microphone.
This list will explain what each specification means for the most important specifications. We are not experts at this so if you feel something is missing in this list or it is technically incorrect, let us know in the comments below and we will add/fix it.
A decibel is used to measure the level of sound and it is based on human hearing. It is usually abbreviated to dB.
A dB of zero (or 0dB) would be no noise, at least to our human ears. A live rock concert might be up in the range of 120dB.
Self noise is the amount of noise the microphone makes. In other words, the level of hissing, humming or buzzing noise. Every microphone has a self noise no matter how good it is. The trick is getting a microphone with the lowest self noise possible.
The self noise is not always listed in a microphone specifications but when it is what you want to look for is a self noise as low as possible. It will be listed something like this in the specifications:
Self noise: 32dBA
One of the ‘worlds quietest microphones’ is the Rode NT1A with a self noise of 5dBA. Our Soundman binaural microphone on the other hand has a self noise of 32dBA and our Free Space Pro Binaural microphone has a self noise of 14dbA. So the quietest microphone in this case is the Rode NT1A.
Signal-to-Noise Ratio (S/N)
The signal-to-noise ratio is usually written in the specs as S/N and is just another way of determining the self-noise of a microphone. In this case, the higher the better. So a signal-to-noise ratio of 80 dB is better than 60dB. The higher the dB the quieter the microphone.
Sound Pressure Level (SPL)
The sound pressure level measures the intensity of a sound and it is measured in decibels (dB). It might read on the specs as ‘Max Input Sound Level’ or ‘Maximum SPL’.
At a human hearing level, the lowest sound we can hear is an SPL of 0 db. An average conversation would be around 70dB SPL and a rock concert might be around 110dB SPL. It starts getting really painful to the ear when it gets around 120dB and up.
For a microphone the higher the SPL the better especially if you want to record loud sounds. An SPL of 150 dB for instance on a microphone would be excellent and would mean the microphone could take in a lot of loud sounds before it starts to distort.
Fortunately, when it comes to recording ASMR sounds, we don’t need to worry too much about getting really high SPL levels as we are recording low level sounds.
The sensitivity is the voltage amount a microphone produces for a certain SPL. Makes total sense right?? If it does, you don’t need to read any further. Otherwise, if you’re like me, then read on. It took a lot of research to get this into layman’s terms that I could understand so I hope it works for you too.
To keep it simple, first of all, sensitivity is measured in decibels. It seems like everything is measured in decibels when it comes to these specifications.
Second of all, sensitivity is indicated as a negative number. So you might see a sensitivity in the specs of -28dB.
And thirdly, the higher the sensitivity the more sensitive the microphone. Aww, the poor microphone. It needs to toughen up a bit and not be so sensitive.
Remember now that we are talking in negative numbers so -40 is actually a higher number than -60. So a microphone with -40dB is more sensitive than a microphone with -60dB.
When it comes to ASMR we are looking for a higher sensitivity microphone because we are dealing with low level sounds.