Sound depends on the signal content, amp, speaker , acoustic environment (=interacts with speakers) and what the listener likes.
If it happens that the amp power is high enough and the speakers are good enough for increasing the bass content of the signal you can insert a bass boost circuit. Change R1 to about 200kOhm and insert with parallel of R1 the series of another about 200kOhm resistor and a capacitor. That lifts bass 6dB with "shelving" principle. A good start for finding a good capacitor is 6,8nF.
Hopefully you can make elementary reactance calculations. Otherwise understanding this quantitatively is hopeless. Qualitatively the idea is to double the voltage gain and take it back gradually as the frequency grows.
As well you can add another 100kOhm in series with R1 and insert a capacitor in parallel with it. A good start for finding a good capacitor is 15 nF.
Nothing guarantees this kind of bass boosting is what you expect.The concept is complex and proper solution needs to know what you expect, what your signal has and what the speakers can output with power this low. I guess you must make C3 smaller to prevent sub-bass notes smudge everything after you have lifted things around 100Hz.