Yes, it is possible to customize the components of a DIY speaker kit. Many DIY speaker kits come with pre-selected components, such as the woofer, tweeter, and crossover, but some allow you to choose your own components or provide options for upgrades. For example, you might be able to choose between different types of woofers or tweeters, or upgrade to higher quality crossover components. If you are building a speaker from scratch and sourcing your own components, you have even more flexibility to customize the components to your liking. Just keep in mind that the specific components you choose will have a significant impact on the performance and characteristics of the finished speakers, so it is important to do your research and select components that are appropriate for your needs and budget.