Mine has a sound like whats been described...I pretty sure it is lifter noise as it is non-existent when cold. Each of my bikes has had it to one degree or another in the same rpm range described above. I switched to synthetic (amzoil) and that made a difference each time for me anyway.
It's not just the FI bikes my carb models have always had it too. It's the rockers slopping back and forth on the shaft. Or loose valve train tolerances. You can try to quiet it down but it takes some skill. Tear down the top end and shim your rockers. That's wear most of the noise is coming from. it's a harley after all they all do it.
My 09 was pretrty quiet when I got her. Changed to all synthetic oils at 1000 mile mark, tick, tick, tick...changed back to HD 20/50 and Formula + in chain case and tranny, no more tick, at least I cannot hear it....go figure... ALL Harleys have their own 'individual' noises. Some we get used to, some we gotta hunt and kill!