How To Adjust Audio Player Width?

I’m using the audio shortcode:

My Audio Title Here
[audio mp3="https://www.mydomain.com/.......mp3"][/audio]

But my audio volume is on another line:

https://s10.postimg.org/cdz6aihft/Screen_Shot_2013_10_17_at_1_38_27_PM.png

How can I adjust the audio player width?

The only way i can do now is adding   to the end of my audio title ie:
My Audio Title Here       

Can somebody please help?

Thanks!