Native Sound System on Nexus 7

[gp123]

I'd like to know more about the native audio system on Nexus 7. 

When I play audio app that does not have its own audio output (like a podcast or text-to-speech app) what controls the qualities of the audio output?  Is it Google Play or something else?  Is signal equalization or preamp possible, or is my control limited to only to Volume via Settings or rocker-switch.

If I install a music player with audio controls (like PowerAmp) is there a way to make this my default audio controller for all Nexus sound?

[matt]

On amazon market, the free app of the day is Music Volume Equalizer, it supposedly works with Google Play Music and other programs in the background.

sent from me n7 using tappitytalk 4