1. The option you have changed is not being used anyway - note the "#" at the beginning of the line. This comments out that line.
2. Buffering radio streams will only help if the problem is a result of erratic download speeds from the site. Increasing the value, therefore, will only help if your download speed from that site is very erratic. It will do nothing for you if your (time) averaged download speed from that site is not sufficient to support the stream rate.
On point 2, you can a) try determining how erratic the speed is, what the time averaged speed is, and what the actual stream rate needed is to see if it is even possible for you - but fundamentally, buffering is never a solution to a broadband connection speed issue, or internet speed issues generally; or b) find an Internet radio station "closer" to you to avoid latency, congestion etc. Many ISPs repeat radio stations and thus guarantee that you get a consistent speed limited only by your internet connection - research that.