I went with the Q4 on my bike as well, and even though its not that loud, its still at the upper limits of what i consider tolerable noise.
Since many offroad riding areas have noise limits and offroad motorcyle riders are not exactly the darlings of the environmentalist whacko-close the trails crowd, why would you want to on purpose make your bike obnoxiously loud?
It's a free country and you can do as you please, but ripping by some trail hippie on a woods hike with your 110 dB exhaust roaring may be the thing that finally inspires coffee shop talk to become action in the form of writing their congress critter to ban motorcycles from parks and other multi use riding areas.
Like it or not, you are an ambassador for your sport everytime you ride in public areas. Because many in the cruiser crowd have been unable to self regulate when it comes to slapping 12" long straight pipes on their hog and rattling windows for a 6 block radius, government is starting to take action. When a bunch of other states follow Californias lead in basically banning any exhaust mods after 2013, there will be a lot of crying and wailing and gnashing of teeth and talk of "treading on my freedom", but it wont do any good because we are an awful small part of the population. And it all could have been avoided if people could have just used some common sense and courtesy.
2008 B-King - Bone stock
2007 KLR650 - Moab shock - Progressive springs 10wt oil - Happy Trails fork brace - Steel front brake line - ProTaper Evo - Acerbis Rally Pro guards - Uni Filter - KLX needle - De-Snorkled - Slide drilled - FMF Q4 - DooHickey done - Swingarm pivots drilled/tapped for grease Zerks - Custom (homebuilt) mount and Pelican 1450's.