Why close Reaper to play MP3?

Hi all- I'm sure once again I'm missing the obvious, but here goes my question: If I'm working in Reaper and then decide I want to reference an MP3 outside of Reaper why is it that I have to close Reaper to get my MP3 to have audio? Ex. 1. Reaper open with some guitar takes, and I can hear everything fine. 2. Want to hear a riff that's in My Music folder on my desktop. 3. Minimize Reaper>Double click on My Music folder> double click on song I want to hear. 4. I can see the bar moving but no sound. 5. I then close Reaper and replay the MP3 and I get sound. I have all my sounds (Sounds & Audio Devices) set to play through my Lexcion Omega. I figure I have some sort of conflict but I can't figure out what/where. I searched the forums but couldn't seem to find an answer. Thanks in advance. Cheers

You can assign Reaper to a dummy audio device (or vice versa?). Just left click on the upper right hand corner where your audio device info is shown. Select dummy audio device (or something like that). You're clear to listen on your other app. Kyle

just enable "close audio device when stopped and application is inactive" under preferences/audio/device ...

just drag the mp3 into your session into a new track. instead of routing that track to master, route it directly to your soundcard output. then mute the track. if you want to compare it to the rest of your session, solo it (make sure nothing else in your track is soloed). it's a good way to do compares.

I can play mp3's or stream audio at the same time as having Reaper open with only having "Close audio device when stopped and application is inactive" checked