A:Answer Hello, great question! If you are looking at wattage, we are going to guess that you want to know which speaker is the most powerful or which speaker is going to be able to play the loudest. Wattage can be misconceiving, so let's take a look at the speakers on a measure that will allow us to compare their audio performances on even ground: SPL rating. This rating gives you a rough idea of how loud the speaker will play with a specific amount of power at a specific distance.
The Stockwell II has an SPL rating of 80 dB SPL @ 1 m; The Kilburn II has an SPL rating of 100.4 dB SPL @ 1 m; and the Tufton has an SPL rating of 102 dB SPL @ 1 m.
If comparing all of the portable models, the Tufton definitely can pump out the loudest tunes. If specifically looking at the portable "II Bluetooth" speakers than the Kilburn II will be the loudest. All 3 of these speakers sound amazing, but the loudest is definitely the Tufton.