Generally if the original speaker is a well designed model for its price point, it is not a good idea to just replace drivers. The cabinet should have been designed to match the characteristics of the woofer for low frequency extension, compliance, efficiency and so on. Similary the crossover needs to match the characteristics of both the woofer and tweeter (and midrange if one).
Putting another driver in place ignores all of these factors. Even if it is "higher quality" driver, the chance that it will match the needed characteristics is simply a shot in the dark.
If you want to learn about speaker design, determine the original design specs and then pick a replacement driver based on that info, your odds of good results will improve. But the relationship between components in a speaker is complex and it is easy to overlook things. You may think you've covered all the bases and still find your change is not an improvement.
The key is to treat the speaker as an integrated whole where the parts match each other.
Putting another driver in place ignores all of these factors. Even if it is "higher quality" driver, the chance that it will match the needed characteristics is simply a shot in the dark.
If you want to learn about speaker design, determine the original design specs and then pick a replacement driver based on that info, your odds of good results will improve. But the relationship between components in a speaker is complex and it is easy to overlook things. You may think you've covered all the bases and still find your change is not an improvement.
The key is to treat the speaker as an integrated whole where the parts match each other.