Thanks for the replies. The gain structure is very different to an Ashdown, I've had CTM100, ABM600 and a Retroglide through this cab and the volume was roughly at 11 or above using those.
The pad is already on. I could use my pre amp to lower the signal to the head but that's not what I'm asking.
Using the same head set at the same volume but with a smaller cab.. 2x10 or 1x15 will I be noticeably quieter?
As brilliant as the cab is, I'm not precious about the Four10, It'll be up for sale tomorrow if the answer to the above is yes.
...and no I don't play in a library, although we have played at The Library in Leeds.
Cheers