(I imagine this question is asked often.)
I understand mixing Ohms is basically a no-no. One speaker will overpower the other.
WGS suggests mixing Retro 75 watts with Reaper 30 watts, or 50.
Is there a downsize to this? Wouldn't it be safter just matching up Watts evenly. Or does it not matter and you add up total and not overload?
My 2X12 is designed for 100 Watts. Should I be concerned if I load with 105 Watts?
Mixing wattage is fine ... but remember that in a 2x12 each speaker will need to be able to handle 1/2 the amps wattage (1/4 in the case of a 4x12) ... so a Retro 30 (75watt) and a Reaper (30-watt) would only be appropriate for an amp of up to 60-watts RMS. As the weaker link, the Reaper would blow long before the Ret.
A Reaper HP (50 watts) & a Ret would be good for up to 100 watts RMS.