Sound source power

According to ISO 140-4:1997 we have to make sure that the sound source power is sufficient. If measuring according to the “old” standard the sound pressure level in the receiving room should be at least 10 dB higher than the background noise level in any frequency band. If the level is only 6-10 dB higher than the background noise, WinMLS applies a correction for the background noise level. If the level is 6 dB higher or less, the results should not be used and WinMLS will give a warning about this when the final result is calculated.

Note: These background noise corrections shall not be used if using the new impulse response based method since the impulse response method automatically adjusts for the background noise. If using the new method it is therefore not required to measure the background noise.