This auction is for a copy of a set of  plans to build a JBL 4520 (C55) Bass-Scoop Rear Loaded Horn.

The plans are six (6) pages with a assembly instructions.

This is a rear loaded horn for dual 15 inch drivers. (JBL recommends a  D130 , 150-4C or 2205 PRO driver)

A short throw 4 m (13ft) folded horn, the 4520 provides maximum loading to 42 Hz for applications which require high level sound projection up to 25 m (80 ft).


It exhibits uniform response to 50 Hz and is usable to 30 Hz above 150 Hz the drivers operate as direct radiators.

The exterior dimensions of the 5420  (C55) cabinet are given as 50 1/2" H, 35 3/4" W and 29 3/4" D.