NO, yu are limited to this stock JBL
digital amps limit.
Yu might be able to find a
Sub+Amp to supplement the OE setup, but that's about it.
And, that will just amplify more of the
innacurate low frequencies...
which the JBL is full of .
When upgrading a system...yu want clean and accurate sound....not really more power.
When accurate sound is reproduced...it is possible to raise the sound level more without distortion.
When upgrading any Head unit, the objective is to find the most accuracy yu can achieve for the Money.
Then yu apply a matching AMP and speakers to maintain that Freq. response.
If yu want to change your sound....try getting all new speakers for the OE JBL before doing anything else. Don't buy on price alone. Yu must match/alter speaker specs when changing the Stock JBL speakers out.This topic belongs in another more appropriate section of TS.
LT