iOS application to play subs and music at the same time?



I’m looking for a solution.
I want to play subs and music at the same time on my iPhone.

As you may know, ios is very limited.
You can use the built in music/itunes app, but that’s about it to my understanding.

I know that there are some 3rd party apps out there but most of them are paid.
Which is not a problem, but i want to make sure they go together with the default music/itunes player.

Does anyone have any experience with this?

I saw a few apps that looked interessting.



When you figure that out let me know lol, i would love to be able to play my spotify music with the ultra sonics at the sametime on my phone, but sadly phones are limited


Only solution i’ve came across is a ‘‘DJ’’ app.
This will allow you to play 2 mp3’s at the same time.
It’s not very practical though, since it won’t allow you to lock your iPhone.