db / spl In Simple Terms ??

[Witterings]

Can anybody explain to me in simple terms what db / spl are and what difference say 110 or 120 rating would be ??????

 

[Lt. Bob]

A decibel (db) is the smallest amount of volume change a human ear can detect.
A 10db difference is roughly double percieved volume so 120db would be approximately twice as loud as 110db.

here:
http://www.sengpielaudio.com/calculator-levelchange.htm

 

[Witterings]

Lt. Bob,
Thank you for that much appreciated and very useful !!!!