Hi! In another post, Waveraver and I made a head about the meaning of sound pressure. He says that volume and sound pressure is the same, I say that sound pressure is about pressure fluctuations in the air. I’m not quite sure. What do you mean???? PS: @Waveraver: Shouldn’t be directed at you, but I’m just interested in what sound pressure is now, or SPL is… What is SPL?? 🙂