I you're satisfied with your system and its sound then you don't have to change anything.
If you feel you want something new you will have to try different things like different brands or types of speakers or amps and see if something suits you. This may not cost much more than your current parts but if you for example go from box speakers to horn you may have to change your amp too.
If you want clearly better sound you may have to change many or all parts of your system. My thinking is that you can start with for example speakers but should budget for something that costs 50% to 100% more than the ones you have to get a clear improvement. I personally just changed my amp to a much better one and it really lifted the sound. I could not afford to buy a complete new system at this level but if you have that budget then just knock yourself out. It looks like your speakers are below your amp so new speakers may be a good idea.
If you feel you want something new you will have to try different things like different brands or types of speakers or amps and see if something suits you. This may not cost much more than your current parts but if you for example go from box speakers to horn you may have to change your amp too.
If you want clearly better sound you may have to change many or all parts of your system. My thinking is that you can start with for example speakers but should budget for something that costs 50% to 100% more than the ones you have to get a clear improvement. I personally just changed my amp to a much better one and it really lifted the sound. I could not afford to buy a complete new system at this level but if you have that budget then just knock yourself out. It looks like your speakers are below your amp so new speakers may be a good idea.