General soundboard question

Hi,

So i'm 16 and i am a live mixer at my church dealing with the live performance ect. i have been mixing for over a year and can get a good mix esaly but i know nothing about the science behind it all. I have a simple question, I have had this explaned to me but they told me alot that day and i dont want to ask again right now. On the mixer the sliders go from -80 to 40 above 0. If i rember correctly the media director told be that was Db and i am wondering how you can have a negitave Db? I use a Yamahaa 2200 i belive it has 56 channels if you are wondering what i am reffering to look next to the sliders. It would be great if someone could explane the scaling system to me. also at the bottom it has the sign for infinity so i also am thinking this scale may just be ohms used to reduce or, above 0, amplify the sound. any info would be great.

Thanks ahead of time and sorry for any misspellings or grammer errors.

It's db's. In this case, it's used to express the amount of gain you are applying with the channel strip to the input signal. 0db is unity, or no gain, or the channel strip output is equal to the input. A positive number means you are applying a boost, and negative number means you are applying a cut. the infinity sign at the bottom means the channel is off.

If you really wanna know about db's, go here:

http://www.phys.unsw.edu.au/%7Ejw/dB.html#recording