I have an o/r H and 2 40 Series.....All of my friends can hear me from 3 blocks away and they are obnoxious!!!! (but I love it) They are really loud, but I don't know if you can find the 2 chambers anymore (or so I have been told).....but I got mine on ebay REALLY cheap, just type in Flowmaster 40 series and they should come up if the company still sells them. I think I got both for 75 bucks!