The speaker and your phone or decibel meter's locations are CRUCIAL for this test to work correctly. In order to place both at the exact same spot each time, we used foam board and cut out pieces on both ends, which included an opening for the speaker and an opening for the mic/cell phone.
In order to keep both in place on the testing unit, we used hot glue and tape. This instruction is completely dependent on the speaker and mic you use.
Once complete, your assembly is ready to go!