How many watts you need... depends on your system. The three most tell-tale indicators are: How loudly do you listen? How is your installation? How sensitive are your drivers?

SQ has never been loudness wars. It has always been: tonality, soundstaging, and imaging. If you do not know what those three are, Google is your friend. For what it's worth, most "SQ" judging sessions consume less than 200W in most cases.

I keep telling people. There's no SQ watts, there's no LnC watts. Watts is a measurement of rate of energy transfer. There's only OUTPUT. You can have a 2000W RMS mono amplifier feeding a 0.75 cu.ft sealed box and my 3 cu.ft ported box with 300W of power will STILL be louder.

People are overthinking your wattage needs and underestimating how powerful 100 watts really is. In fact, when you're simply doing background listening (80dB), you're using something like <20W of power.