There isn't an ohm setting on any amplifier. A lot of people new to audio get this confused. There are only a limited number of ways you can wire your woofers that determine the ohms load. Which ever load you prefer/need to get the desired power to your woofers is the load you choose from the few choices. We need to know the number of woofers and their coil type/ohm rating. Think of it this way. You have a bad ass car (your amplifier), but you hook up 4 tons of dead weight behind it (4 ohm load) its going to slow the car down. Or in the case if your amplifier, it won't produce a lot of output power. Well if you lower the load, the car goes faster (amp puts out more power). If you don't have enough load, your car will break loose and you will end up in a ditch. (You're amp will get damaged) Although people run sundowns at 0.5 ohms daily, they have a good/great electrical system (or they should). If you're electrical isn't special, stay at/above 1 ohm.