Marine speakers are designed to survive in the hostile environments of extreme temperature changes, vibration, moisture, and dirt found in boating and off-road motoring. Not only must the material of each individual part — like a speaker's frame, surround, cone, and coil — resist contamination, but the wiring and adhesives that hold all the pieces together need to resist corrosive damage and remain functioning.Normal car and home speakers just aren't up to the task.