Its hard to say without seeing the venue - composition of the audience etc.

Neil Dalton and Rob Henry have within the last year opened a similar sized venue at a brick kiln that has been converted to an auditorium in Swadlincote and not had a single empty seat.

It might be an idea to check their guest list - they seem to be establishing themselves very quickly.

Neil is a very nice guy and I am sure will give you some tips. people were starting to despair of ever getting a really good acoustic venue in the area.
I'll just pop down the relevant contact paragraph from their e-mail circular. Hope this helps.
'The doors open at 7.30 pm and tickets are £8.00 and are available on the door on the night or, beforehand, from Sharpe's Pottery Museum during their opening hours (10 am to 4 pm) or can be reserved by telephoning either the museum on 01283 222600 or the Real-Music Club on 01283 701656 or online at www.wegottickets.com/evenue/525.