Currently we know of no way to switch on JBL Go 3 low frequency mode. But if this were possible, it would make the speaker vibrate much more. Plus it would add a louder bass quality to the audio. Thus if they ever added this, it could work something like the following…
How to Switch JBL Go 3 Low Frequency Extra Bass Mode OFF and ON – Proposal
First of all, by default, the Go 3 would have its extra bass mode turned ON. This is like many of the other speakers in the JBL line. This mode would add more treble and lots more bass to the audio output. It’s like switching on the Loudness control on vintage stereo systems.
How to Turn JBL Go 3 Extra Bass Low Frequency Mode OFF — Proposal
For example, find the Bluetooth and Volume Down buttons on the top of the speaker. So find these circled in the picture above.
Then, you could turn this extra bass mode OFF by pressing the Volume Down (-) and Bluetooth buttons. Hold them in until the pilot lamp blinks a few times, as we show in the next picture.
Finally, to turn low frequency mode back on, again, you would press the Volume Down and Bluetooth buttons. Then, hold them in until the light again flashes a few times. You would release the buttons after that.