Peacemakers

Maybe one or some of you can help me understand the theory behind the "peacemaker" pipes...and there's another brand out there that I can't remember the name of right now. Anyway, I took advantage of a good day yesterday and went to one of my buddies' house. He told me that he is considering putting the peacemakers on his 07 softtail because his neighbors complain about his loud pipes so much. Here's my question...if there's a switch that moves a baffle from "closed to open" thus making the bike "loud or quiet", how is the proper backpressure maintained?

I understand the theory that they describe but am lost as to how the proper backpressure is maintained.

http://www.peacemakersexhausts.com/

Although I know the "backpressure is necessary" idea has been around forever, I don't know where it came from & it's also wrong - backpressure is always bad.

I looked @ the website & the idea is much the same as the one Buell uses - 2 different exhaust paths depending on throttle position & engine rpm. Buell does it with a "trick" muffler for more top-end power, "Peacemaker" does it for sound level, but the overall affect is pretty much the same - re-directing exhaust flow rather than choking it off. I have no personal experience with the Peacemakers, but they ought to work.

Thanks all...I've been listening to the "backpressure" saga for years now and wasn't sure about it's accuracy.