I love the burbling sound of the triples, my Ultra was a triple as well, but only a single stock pipe. These triple pipes and the dynoport can make it alot harder to identify all the sounds the engine makes...the crackling is what I sometimes fret over if it's pre-ignition or detonation as some pops and crackles are louder and more distinctive, but I think it depends on the surface and what the exhaust is resonating off of and which side of the sled I'm leaning over. Some more time in the saddle and I'll develop a greater sense of it all.