A simple venturi set up for a cooling fan sytem?

I'm trying to make a cooling unit for some computer case fans, i could buy something to cool the system but i'd rather make it myself as i like a challenge. I'm thinking of two openings to fit the fans and a venturi in the middle. Would a venturi in effect restrict the volume of air or would i get the same volume because of the increased speed in airflow? And would a venturi increase the noise, or would baffling be of any use?