Calculating sound attenuation with rolloff


I was hoping someone could help me make sense of sound attention calculations, because the more I try to look into it the more confused I become.

So from what I can tell the main way that you're able to calculate attenuation is with the formula

Attenuation = Volume-20*log(Distance/Maximum distance)

Which makes sense, and I see that a lot of places also mention a minimum distance, which I understand as being the distance below which attenuation is always 1, that is, attenuation doesn't apply until after that point.

However my problem comes when I tried to work out what rolloff does. From what I understand it's just controlling how fast the volume drops over distance, however this turned up an entirely different equation:

Attenuation = Minimum distance*(1/(1+Rolloff*(1-Distance))

And this is incredibly confusing to me, as it's really, really unclear as to where, how or if these two equations interact. More confusing is that occasionally that formula returns a value > 1 at Minimum distance. I haven't seen any variation of the first equation which includes rolloff, which makes me more convinced that there's some connection between the two that I'm just not understanding.

I'm sorry if this is a stupid question and I've just massively overcomplicated this, but I'm very lost and any further research seems impossible because I feel like I'm lacking the terminology to articulate what I'm looking for


Posted 2021-01-14T10:35:25.760

Reputation: 1

1Are you talking about using an attenuator in an electrical circuit or the decreasing in volume the further away you get from the source? – Timinycricket – 2021-01-20T06:53:02.217

No answers