Quote Originally Posted by Duffy View Post
...... I had no idea that the response of the ear to the frequencies of sound, and the SPL too I suppose, has such an affect on the sound we perceive; as opposed, I guess to the actual sound wave pattern generated by the amp and speaker and pushed thru the air. It sounds like what we hear is regulated by our human condition;
If you enjoy mulling that concept over in your mind, consider that the exact same situation occurs with what we see. I'll be brief cause it's wildly OT, but light is also a wave (yes I know it can also be a particle, but leave that out for now). When we look at a something, the colours we "see" are in reality just our brain interpreting the eye's response to different frequencies. Blue is not "Blue". Blue is what our brain comes up with when our eyes are hit with a frequency of around 650THz.

Think about that for a while.

I have some info around the rest of your post too, but work beckons. I'll get back to the physics lesson later