To increase the volume of an electronic device. E.g. He cranked it up a little more and CRACK, there went both speakers! Kelly cranked up his stereo until we were nearly deafened.
Fig. to accumulate something; to collect or acquire something. E.g. They all racked a lot of profits up. We racked up twenty points in the game last Saturday. To obtain a large amount of something . E.g. We racked up a lot of miles on our last vacation. Laura is starting to rack the money up now.