We had a pleasant stay at Monella's apartment which is perfectly located in the centre of Bologna, yet silent on Friday/ Saturday nights. From there, you'll find most of the hotspots within walking distance.
Monella wasn't in Bologna that weekend but she promptly replied to our questions and gave us some valuable tips.
Definitely would stay again at Monella's place and can only recommend it if you're looking for something unusual (how often have you waken up under a fresco ceiling?).