Here is a technical answer. Watts is a measure of power. Amps is a measure of current. The relationship between the two is Power in Watts is equal to Current in Amps multiplied by Voltage in volts. Power = Current * Voltage. Generally speakers are rated in Watts. This is the power that the speaker can handle. Now, you will need an amp that puts out 30W to reach the maximum output of a 30W speaker. Another consideration in speakers is the impedance. This is usually stated as 4 Ohms or 8 Ohms. Ohms are a measure of impedance. The equation governing this is voltage = current times impedance. One can also say current = voltage divided by impedance. This is important. If you drive an 30 Watt speaker rated at 8 ohms with a 30W amp rated with a 4 ohm load, you will only get 1/2 the current and therefore half the power. To get the maximum out of the speaker you have, you must get an amplifier capable of producing 30W given the speaker's rated impedance. I hope that makes sense.
