Product descriptions typically include a “Noise Reduction Coefficient (NRC) rating” between 0 and 1.
The higher the number, the greater the absorption.
While this number may seem important, the truth is…it’s pretty much worthless for recording studios. And here’s why:
The test to determine this number only measures absorption at 4 frequencies:
- 2000 Hz
- 1000 Hz
- 500 Hz
- 250 Hz
Which means that no measurements are done below 250 Hz, where virtually all problematic frequencies in the studio exist.
That is why a different metric, known as Sound Absorption Coefficient (SRC), gives a much better representation of true performance.
Because this number measures absorption at a specific narrow band of frequencies. Unfortunately, it’s pretty uncommon these days to see SRC numbers actually posted.
One thing to keep in mind, when trying to absorb sound and prevent it from moving through walls that the only thing that stops sound (particularly the low frequencies) is mass. There is one item that sound shares commonalities with and that is bullets. Just like a large caliber bullet is very difficult to stop so are low frequencies. This is why when you are sitting at home and you notice things vibrating in your house when a car goes by playing bass heavy music that it vibrates things in your house. Low frequencies have a lot of energy behind them to push them and this is why they are difficult to tame unless you build your walls with that intention in mind.
- On 08/09/2024
