You can adjust the bass response of the JBL Flip 3, by toggling its Extra Bass mode. When ON, this mode makes the passive bass radiators vibrate more. So in turn, this adds a beefy extra low, “boomy” quality to the content playing.
JBL Flip 3 Extra Bass Mode: Explained
First off, by default, the Flip 3 has this mode ON. This adds a bit more treble as well. It’s like switching on the Loudness control on 1970s stereo systems.
How to Turn OFF
Turn this mode off by pressing and holding in the Volume Down (-) and Bluetooth buttons. Then hold for about ten seconds, until all the lamps on the top panel light up white.
Find these buttons near the top of the speaker.
How to Turn ON
To turn Extra Bass mode back on, again, press the Volume Down and Bluetooth buttons. Hold them in until the Power and Connect+ lamps light up again. Then release the buttons.
Finally, Extra Bass mode is ON once again. Further, if you did connect with a BT device, the Power button turns blue again after a few seconds. Also, if you hadn’t connected this speaker via Connect Plus, then the Connect+ button also goes dark as well.
Note that Extra Bass mode can drain the battery significantly faster. So if you plan on using the Flip 4 away from a charger, turn this mode OFF. This helps maximize the time per recharge you get. So you won’t have to worry much about the speaker running dead before your party is over.