10-06-10: FranksThere's no debate that large woofers require more power, but I want to point out the Model IV has a 12" woofer -- not 15". The amount of power you need depends on how loud you play. If you tend to rock out, then 200 watts makes sense. If you play more conservatively, you can get by with 80 watts quite nicely. The other issue to take into consideration is the impedance. The Model IV is 8 ohms nominal, 3 ohms minimum.
The Alon 4's are different then the other Alon models in that they have a 15" woofer and are very power hungry.
You might want to check this out: Alon Product Manual