I was gifted two Anker bluetooth devices, A3142 and an A3143 with two different but easy to fix issues.
The A3143 had a broken speaker mount (internally) and the A3142 had a It faulty battery protection PCB and charging circuit, but no mechanical problem.
After fixing both, I've noted a strange thing: The A3142 (which is technically more powerful than the A3143) is sounding quieter and the volume seemingly drops when the music gets louder in bass frequencies (the volume is fluctuating) while playing in max volume. The A3143 doesn't have such issue.
This fluctation is quite familiar to me in sound systems that try to equalize or limit the output power.
I've disassembled and re-assembled the A3142 to check if the sealing was air-tight as it should be and if nothing was loose, and everything was ok.
I also checked the health of the batteries and they are almost perferct, they're holding the voltage still while playing and they are discharging as slow as they should.
The speakers are also completely fine, everything seems to be ok, but the volume still fluctuates when playing in max volume (and only when trying to play bass sounds). In lower volumes it sounds just fine.
So, my question is: Is there any volume equalization or limiting mechanism in it? Or some mechanism that tries to limit the output power when in low battery?
And if there is, is there a way to disable it?
Thanks by the help!