Looking at some of the technical specs of today's wireless speakers, one cannot help but be at a loss in trying to compare different models. I will give a short overview of the output power spec in order to help you better understand the meaning of this term and how they relate to the performance of an speaker.
Some of the terms which speaker manufacturers publish often are misleading and do not necessarily give a good indication of the actual performance of the speaker. Now I will give some details about "speaker wattage". This spec is often misunderstood. It is important to look fairly closely at how the manufacturer shows this parameter.
"Wattage" shows how loud your loudspeaker can sound. You want to pick the speaker wattage based on how large your listening environment is. For best audio quality, you may want to go with a speaker that has higher power than you need since many speakers will show increasing distortion as the audio power goes up.
There are two common ways to display loudspeaker wattage. These are "peak power" and "rms power". "Peak power" describes how much power the speaker can tolerate for a short burst. On the other hand, "rms power" describes how much power the speaker can tolerate for a prolonged amount of time without being damaged. The peak power rating in the past often led to manufacturers showing large wattage ratings for small speakers. However, in reality those speakers would not be able to endure larger amounts of output power for larger amounts of time.
Today most speakers will specify rms power which gives a better indication of the speakers' true performance. However, please ensure that your speaker has enough headroom to avoid clipping of the audio. This is because at certain points in time the signal will have bursts of power which by far exceed the average power of the signal.
Usually the impedance of the speakers which you connect to your amp will determine how much power your amp can deliver. Speaker impedance is measured in Ohms. Typically speakers have an impedance between 4 and 8 Ohms. An audio amplifier which has a fixed internal supply voltage will have a maximum output signal swing that is limited by that supply voltage. If you are driving an 8-Ohm speaker then your amplifier must deliver twice the output voltage than when driving a 4-Ohm speaker in order to deliver the same amount of power to your speaker. Usually maximum power is specified for a 4-Ohm speaker impedance. However, ideally the manufacturer of your amplifier will tell which speaker impedance the amplifier can drive. Please note that some amplifiers cannot drive speakers with very low speaker impedance.