Whats this Concert rear connection

[the slob]

Can anyone tell me what the brown conector in the center is for?

http://img.photobucket.com/albums/v251/boraboy/RIMG0180-2.jpg

[theskuh]

alarm ground? Possibly? I know the symphonies have them

[LondonRS4]

It's a FAKRA RF connector. It's for an antenna of some sort.