What is ur device? can u try some volume managers, e.g DSP sound routers or else, does the normal ring more loud or the problem is only with skype? I think ur DAC is not Full-open (on some chiniese devs this is regular issue)
Thanks for the tip for the iPad! I am on a Macbook Pro and I have the same issue but don't see where I can change the volume. My computer volume is high but I still don't hear the Skype ring. Speakers and call quality are perfect, just no ring volume.