I've not used SetCPU since my S2 days Syd, so I wouldn't know.
Are you getting rectal retorts on KT and Alucard too?
The following has always worked for me to get rid of any trouser coughs:
KT:
* Never had any pocket frogs using ondemand or interactive
* Used to experience eggy chuffs on ktoonservativeq, but after setting disable_hotplug_bt=1 and disable_hotplug_media=1 its been 100% flatulence-free
Alucard/Googy:
I used to get air biscuits constantly even after no end of messing with hotplugging options, but has been bereft of bottom burps for a good 6 weeks or so now since recent kernel versions. As you're still experiencing googy guffs then I would suggest changing hotplugging to possibly msm_hotplug and msm hotplug booster to 2 cores boosted. Sched_mc is another possibility. Might also be worth tweaking your internal/external read-ahead depending on where you're playing your music from. It's a case of fiddling until anal announcements are reduced or eliminated.
If your S4 is still squeezing out smelly shards even after all this, then for test purposes at least, it would be worth trying another ROM (eg. SlimKat/SlimSaberKat or even, heaven forbid, a TW ROM!)