If you're only going to a small hall, why not use one of the Reverb settings?

You will find these by pressing:-

PROGRAM MENUS (on the right of KN under the Red Record button)
This will take you to the first of 2 pages of suggested reverb settings for various sized venus.

I sometimes play in a Community Hall and find the setting 'Large Hall-1' (on page 2) is more than adequate for the job, but of course, it does depend on the hall itself e.g whether it has wood flooring or a carpet.

Try it out at home - you will be surprised at the differences.

Good luck!

Audrey