The JBL Charge 5 portable bluetooth speaker was just announced in 2021 but it's predecessor still has plenty of power. In fact, the main driver is fed with the same 30 watts as the new JBL Charge 5, which also has a separate 10 watt channel powering it's newly added high frequency driver.

In this video I'll show you a simple mod that will take your JBL Charge 4 to another level if you like using the LFM (aka low frequency mode or disable DSP). Anyone who got a JBL speaker and used this mode have probably noticed that if you "push in" one radiator, the other has more excursion. But also the bass response improves slightly. That's because the speaker wasn't designed for LFM (obviously) so they've tuned the enclosure for a higher bass frequency (about 65 hz I think). By closing one end (basically eliminating one passive radiator) we are retuning the speaker for a lower frequency. From my tests, with this mod the Charge 4 can easily go down to 40 Hz or even lower giving music a nice low bass punch. Other benefit is that the speakers driver is more controlled so it won't bottom out that easily due to high excursion thus being a bit more protected from damaging. Of course, using LFM is risky either way, so I'm not recommending using it if you're not sure what you're doing and you should always keep volume under 70% to avoid damage.

Background music:
   / retnikdubs  

Test songs:
Wizard - I don't mind
Yaboii - Dynasty