For bookshelf speakers in typical rooms, 30–60W per channel is sufficient. For floorstanding speakers or larger rooms, 80–150W is recommended. Speaker sensitivity matters as much as power — a speaker at 88dB needs half the amplifier power of one at 85dB to reach the same volume. The Audiolab 6000A (50W, AU$1,199) suits most bookshelf speakers. The Audiolab 9000A (100W, AU$3,499) suits demanding floorstanders.