You can change how loud the bass is on the JBL Xtreme 3, by turning on its bass mode. When active, this super bass mode makes the passive bass radiators vibrate a great deal more. Plus, it adds a deep rumble trait to the playing program as well as a bit of extra treble too. This enhanced bass travels pretty far from the speaker.
How to Turn On JBL Xtreme 3 Bass Mode
By default, the JBL Xtreme 3 has its bass mode turned ON after resetting. This adds some treble and increased bass to the audio output as compared to when this mode is OFF. Also, the midrange levels sound like they drop a bit when bass mode is active.
You can turn extra bass mode ON by pressing the Volume Down (-) and Bluetooth buttons. Hold them in for about ten seconds. Then release them when the Power and Bluetooth buttons, and the surrounding oval, all light up white. We point at this with the green arrow. E.g. Find all these buttons on the top of the speaker, as shown in the picture above.
To put bass mode back to what it was before, then again, press the Volume Down and Bluetooth buttons. Hold in until the oval, along with the Power and Bluetooth buttons light up white.
Then release the buttons. Finally, when the the oval goes out, the low frequency mode is active once again.
Warning
The drivers really thump when you switch ON the low bass mode. So use care in how loudly you play this speaker with this mode ON. Doing so avoids damage to the drivers inside. In fact, if the bass is ever crackling, tapping, or otherwise distorting, turn it down