General Advice
We recommend that you choose an amplifier that can deliver twice the loudspeaker's RMS power rating. For example, the Koala 12m requires an amplifier that can deliver 600 watts per channel into 8 ohms because it has a nominal impedance of 8 ohms and an RMS power rating of 300 watts. Loudspeakers are most often damaged when amplifiers are driven into clipping. More powerful amplifiers are less likely to be driven
into clipping because they have more headroom.
If you attach two loudspeakers to the same side of an amplifier you effectively half the ohms seen by the amplifier. Most amplifiers will put out nearly twice as much power if you do this. This means that a loudspeaker that can deliver 600 watts per channel into 8 ohms will therefor deliver 1000 watts per channel into 4 ohms.
It is important not to connect too many loudspeakers to one side of an amplifier. This will cause the ohms being driven to fall below what the amplifier can handle which will damage the amplifier. Most modern amplifiers can take a minimum load of 2 ohms.
