I've been stuck on this one problem for a bit, any help is really appreciated. "A loudspeaker is placed between two observers who are 110m apart, along the line connecting them. If one observer records a sound level of 60.0 dB and the other records a sound level of 80.0dB, how far is the speaker from each observer?" I've been having a tough time grasping sound waves in general actually. These problems usually take me alot longer than the previous chapter on wave motion. So I was also wondering if anyone knew some good help sites with sound waves, I seem to only find ones with formula's on them.