This step is not compulsory, but is recommended for additional water proofing. We mark on the back of the door trim the approx. size of the hole in the steel door frame and apply a waterproof coating to the back of the door trim + the inside edge of the speaker hole. This is so that the area potentially exposed to rainwater inside the door frame is waterproofed.
Hold your speaker in position and check the speaker magnet does not touch the door frame. If it does, you may need to shift the SDP a couple of millimetres toward the rear of the door trim. Important note- once you have the SDP in position, check that it does not touch on the plastic cover at the bottom of the B-pillar.
The following 5 steps will be useful if you are installing tweeters in the SDP. The mounting washer is an ideal place to mount the crossover. This position lines up with a large hole in the door frame, so there is plenty of depth available. This position is also waterproof as it is protected by the plastic sheet.