After all the information about the Magnum Horns I ended up buying locally and when comparing the notes on youtube ended up purchasing a set of Stebel Chromed Twin Electric Italian Horns for $38.95AU delivered to my door. They came with a relay and my next dilemma was here to mount them?
My '06 TBA is my daily ride and my commute often involves gridlock and slow, very hot running in bumper to bumper peak hour Sydney traffic so the factory horn location in front of the oil cooler between two very hot header pipes just didn't seem to make real sense to me for placing two chromed plastic horns. After some experimentation I actually ended up mounting them either side of my headlight & behind my summer screen. The red relay that was supplied with the horn kit resides where the OEM horn once lived and I will replace this with a chromed horn relay if I can find one. My TBA now has a much more threatening horn blast and maybe this could be another option for fellow readers thinking of alternative mounting horn locations?
