How many watts are needed for a decent surround sound system?

Without getting into a 45 minute technical lesson, Wattage is not the most important factor. Wattage
is simply a measurement of volume. The higher the wattage the more volume it will have. This does not
mean the quality of that volume will be the best. A properly balanced system (receiver, speakers,
amplifiers) with a relatively low wattage, can
out-produce a large wattage system in quality. Too much emphasis is placed on how watts a system carries. Properly balance a large watt system and you have an amazing system to rival anyone!