I know decibels are a measure of a speakers effciency. Higher the number, less power required to achieve a desired SPL. When and how much makes a difference. I have a pair of Wharfedale diamond 8.1 bookshelves rated at 86 dB at 1 meter. I am looking at replacing them with a pair of Klipsch B-2s rated at 92 dB at 1 meter. How significant is 6 decibels from 86 to 92?