Negative SPLs in SPPS 'Sound levels per source' table

[Mark Kubis]

Hello

I have a model that has 15 separate simultaneous point sound sources and I have done an SPPS energetic octave band analysis.

When looking at the table 'Sound level per source SPL' for a Punctual Receiver there are some negative SPL values for some sources at some octave bands. Why is this?

Should I assume these negative values are zero? If so, the remaining sources that have positive values if manually summed (logarithmically) result in a value that is different (lower) from the Total value given in the table.

Any suggestions that would explain this would be welcome.

Thanks
Mark

[Mark Kubis]

After giving it some thought I think that negative SPLs mean that they represent sound pressures lower than 20 micro pascals being the threshold of healthy human hearing. A SPL shown as negative infinity (-inf) means zero sound pressure.

[Nicolas Nico]

Hi,

Sorry for the delay. Negative SPL values is possible, the sound source are not audible. Can't help you without any further details (no data table/ no input data)

best regards,

Nicolas

[Leonardo F.]

Hi Mark,

Maybe you already solve it.

At first time it happened to me too.

Sometimes i forgot to set some value to the sources after put into the scene.

-->sound sources --> source1 --> sound power --> Global LW 

Hope it help.

best regards,

Leonardo