FAQ What is the purpose of the front Apex Coupler? The front Apex Coupler is designed to provide optimal sound performance and integration between the upper and lower speaker cabinets.Can I remove the set-up blocks without any tools? Yes, the set-up blocks can be easily removed by following the instructions in Figure 3.5.Do I need to adjust the front Apex Coupler after removing the set-up blocks? Yes, make sure to lower the single front Apex Coupler into its receiving socket as indicated in the instructions.