DD AUDIO ADP-4

DD Audio Adapter Plate 4" to 4x6" PR (Pair) - Designed & Engineered in the USA Overview The ADP-4 adapter plate is designed to adapt 4 inch REDLINE Coaxial Speakers (RL-X4) and the 4 inch D Series Coaxial Speakers (D-X4B) to factory speaker slots sized 4 inch by 6 inch.