Bang & Olufsen Red Line 45 bass reflex conversion kit

thingiverse

This is an attempt at recreating the bass reflex conversion kit for Bang & Olufsen RedLine loudspeakers. The foam surround of the "ABR" in these speakers invariably failed after a few years. To solve this problem a kit was released to convert these to bass reflex but this is no longer available. More details are provided here: https://forum.beoworld.org/forums/topic/red-line-45-bass-reflex-conversion/ The ports are named after the equivalent area of a circle of the given diameter. This model was created from a picture of the kit and it was difficult to gauge the height of the tube from this. The original port may have a different area. The 44 mm port has been tested on a Red Line 45 (6504) and gives an fb around 40 Hz. Red Line 60 might optimally need another tuning. The FreeCAD file contains more port variants. The replacement plate is available in a full version and one cut in two halves. The port was printed upside down without support.