You perform a JBL Flip 6 reset as follows. Turn on the speaker. Then press the -Volume UP- and Play-Pause buttons. Finally, wait for all lights on the speaker to go dark, and when this occurs, the speaker has now reset. We detail this process below with picture.
JBL Flip 6 Reset, Step by Step
Resetting erases any earlier paired Bluetooth devices from the speaker’s memory. We may wish to clear these because this stops the speaker from pairing to any nearby Bluetooth devices afterwards. Also, you might reset to prepare the 6 for sale or re gifting. Or, just to stop it from pairing with devices you no longer wish it to sync with. So now to the routine in detail.
1. Turn on the Speaker
Firstly, press and hold the Power button until it lights up. Find this button in the next picture.

Then, the Power button lights up along with (briefly) the battery power scale. He

2. Wait for the Power Up Sound
The JBL Flip 6 makes a rising rock guitar strum sound when it powers up. The Flip is ready for use after this sound finishes.
3. Press the Volume UP and Play-Pause Buttons Together
See the next picture to find the Play-Pause and UP Volume buttons. These protrude from the fabric. The Play-Pause button looks like an arrow, and the Up Volume button looks like a plus sign.

The Flip 6 JBL then enters reset, as we see in the next picture. Note that all lamps light up during reset. Then they remain glowing for a couple seconds.

Then after a short pause, the JBL Flip 6 powers OFF. So all the lights go off, and it makes the power-down guitar sound.
4. Check that JBL Flip 6 Reset Worked
Next, power on the device again, as detailed in step 1 above.
Now this time, after reset, our JBL speaker comes up in Bluetooth discovery mode, as shown next. Note that the Bluetooth button blinks white to denote this. Now when the Bluetooth button flashes rapidly, this means that the unit is in pairing mode. Indeed, we expect it not to pair to anything after a reset.

5. Done with JBL Flip 6 Reset !
Resetting is now complete. You may now pack up the speaker for sale, or again pair it with your favorite BT devices. The unit will no longer automatically connect with any previously paired Bluetooth device that is in range. To restore automatic Bluetooth pairing, manually pair the Flip 6 with a tablet or phone. Then, any time that both speaker and that device have Bluetooth turned on, pairing with automatically take place once more.