Yes, you can try to deinstall the fluendo plugin and install the gstreamer1.0-plugins-ugly and bad, to see if this gives better result.
On the other hand,because pulseaudio is installed, is pavucontrol installed (I would suggest to do so)and is the alarm-clock shown there under playback ?
Maybe try out the settings in pavucontrol, it depends on how you want to play the sound.
e.g in my case
I have connected a HD-monitor with loudspeakers and a hifi system
If I want to hear the alarm clock over the monitor, I have to set the internal analog to off under Configuration in pavucontrol.