Strange audio problem

[deth502]

Hey guys, I am enjoying my new phone but have noticed something happens to the audio when listening through headphones and was hoping someone might be able to explain why its happening.

Basically whilst listening to music via headphones (Boomsound is on), sounds good, if I hold the home button, and select Google, the audio changes and sounds better... at least to me. Is there a reason the audio levels change?

Thanks