Yes, a 10 ohm 1 watt resistor connected across the speaker posts will show the amp an approximately 8 ohm load and keep it happy. At only 12w per channel you may not need any attenuation resistors at all. I recommend you try a direct connection first and see if you hear any hiss. If you do have hiss you want to reduce then I recommend this configuration: a 7 ohm 5 watt R2 and a 1 ohm 3 watt R3. Going higher on the wattage ratings is ok.