Installed v&h tru-dual head pipes on my existing v&h slip-ons last night and wow are they a lot louder than the stock head pipes that wasent expected why so much louder?

 

I'm sure that the original crossover exhaust cancel out some fequencies.

 

Must in some way the pipe diamiter from what I could tell is the same I will just have to go get some hog tunes now I guess.