Converting to dBSPL from Pa gives incorrect answer

[ubertakter]

Converting pressure level to sound pressure level gives an incorrect result. Example:

julia> uconvertrp(u"dBSPL", 35u"Pa")
124.86076097372589 dBSPL

The expected answer is 28.750252691799393.

I skimmed the source code but it was not immediately apparent how this value is calculated.

[sostock]

The result seems correct to me. dBSPL uses a reference pressure of 20 μPa, which according to Wikipedia is commonly used for sound pressure in air.

Using a reference sound pressure of 20 μPa, we get

julia> 20 * log10(35u"Pa" / 20u"μPa")
124.86076097372589

Why do you expect to get 28.750252691799393?

[ubertakter]

The result seems correct to me. dBSPL uses a reference pressure of 20 μPa, which according to Wikipedia is commonly used for sound pressure in air.

Using a reference sound pressure of 20 μPa, we get

julia> 20 * log10(35u"Pa" / 20u"μPa")
124.86076097372589

Why do you expect to get 28.750252691799393?

Yeah, no, you are correct. That's what I get for trying to work things out at the end of the day. Sorry about that.

I work with explosions a lot, where the threshold for injury (in terms of pressure) is much higher than the threshold for injury due to noise. Humans is weird.