Day trippin mine were loud as **** at 45 mph between 2000 and 3000 rpm,my twin cylinder has a two brothers on it and it is louder at idle than the n 1000 but when you get on the gas its more mellow, it might just be me not use to the 4 cylinder note, anyway i had some zilla cash so i ordered the factory inserts for the brawlers and if i dont like the sound ill weld some plates with holes in it till i get the sound i want, we use to have to run a muffler on our headers on our dirt track racing karts and all they were was a piece of tube with plates with holes welded in there was like 3 plates inside, i experimented in the gray area of tech on the muffler and it was amazing with barely enlarging the holes with a drill bit the difference it made in sound, im doing it for my wife because i think it will be louder on the back of the bike, lets say i got alot of looks on my first ride and revved twice at red lights by ricers, the bike sounded a whole lot louder than there cars lol.