If the subs are 4 ohm, connect all three positives to one pos. terminal, and all three negatives to one neg. terminal. Two sets are provided on the amp for ease of installation. By doing this, you would have a 1.33 ohm load. The JBL 600.1 does 600 watts rmsx1 at 2 or 1 ohm. That would give you roughly 200 per sub (I know they are rated only for 125, but I am running 300 and they sound great). Hope this helps.