We used to have problems with very low frequencies and background processes (like music playing/streaming ect) when the phone was idle/screen off specifically with DHD's and Sensations - from my memory - and possibly other devices... especially when undervolted as well. Regardless that our devices are a dual core s4, 192MHz x2, is still quite a low setting.
I'm running 192 min. and I listen to music daily at work. I haven't had an issue waking the phone up yet. I'll let you know if that changes though.