Cheap/free Traffic Cone I-phone Amplifier

A cheap or free (depending on how unscrupulous you are) method of creating an amplifier for your i-phone using only a traffic cone

materials-
Traffic cone

tools-
pen
cutting tool of some sort 

additional-
I-phone

as the speaker from the iphone is located at the bottom left hand corner (facing you) you want to mark it roughly 1 half to 2/3rds across the top of the cone down to just above the quater way mark close to the narrowest end of the cone. the gap should be roughly 1.5 cm wide and at an angle

using your cutting tool of choice cut out your marked area.

and there you have it, an incredibly cheap i-phone amplifier. the sound is a little bit tinny but at that price what more can you ask for