Hello Harosha. I just bought the same system, but haven't used it out yet. I am also thinking of adding a sub. If you do, it will have to be a powered unit as the Peavey won't support any added speakers, or you could use a separate powered mixer to drive the sub. The Peavey only has 2 speaker outputs, so you will have to use the channel 5 aux outs to feed the sub. Good Luck and have fun.