As a rough estimate, doubling that small area would change its sound radiation by 3 to 6 dB. That's a small increase from (my guess) a very small number. The amount of sound from the rest of the unit would (my guess) be much larger, and would dominate the dB level. In other words, you are doubling a number that is 1% of the total, perhaps.
Incidentally, adding two dB levels (from two surfaces) is tricky if you're not familiar with it. dB levels don't add directly. dB levels are log functions, and you need to take anti-logs of each surface's level, add them, and then take the log. Doubling a small source that is combined with a much larger source won't increase the total by 1 dB. Again, I'm making assumptions here.
TSN79 said:
So you're saying that in order for sound to pass through a material, the material needs to vibrate to a certain extent?
Yes, in fact if a panel doesn't vibrate, it doesn't make sound at all. Compare the sound of an acoustic guitar to an electric guitar that isn't plugged in. In the acoustic guitar, the vibration of the strings feeds into the body of the guitar, and its light, thin surface vibrates. It acts as a sounding board, or speaker.
In contrast, the body of the electric guitar is relatively dead, because it is stiff and heavy. The string vibration produces little vibration of its surface, so very little sound.
Another example is when you're in a hotel next door to a loud neighbor. When they make noise, it vibrates the wall between you (like a microphone does when you talk). Then the wall vibrates on your side (acting like a speaker). You don't directly hear the noise the neighbor makes. You hear the result of the vibration their noise caused. Hope that helps!
