[m1ku]

I'm using my UE600 earbuds and Nexus 4 (cm10.1, dsp manager, play music app). When I play some songs, it has this strange and annoying sound, sometimes high pitch or a loud boom depends on the song, for a second or less before playing the song. It did not happen on my computer with the same earbuds. What is it?

 

[squallkiercosa]

I do have a Nexus 4 (stock) and I don't hear anything like it. Try using other music app and deactivate the EQ. 
 
There's a thread about the Nexus 4. Try posting to get more feedback.
http://www.head-fi.org/t/634048/google-nexus-4

 

[z7nz]

I suggest installing a different kernel, probably Franco kernel which has sound improvement option (if you buy his app from playstore) and see how things go.
Or try this app: noozxoide eizo-rewire (free from playstore). I'm not sure if it resolves your problem, it's an audio improvement app, makes your phone sound fantastic