Best answer by Mathis
Hmm, odd! It should be fully compatible w/ IE11, yes. By plug-ins, do you mean things like AdBlock, HTTPS Everywhere and the likes? What happens when you try a different browser, or a private window of your IE browser. Does SoundCloud work properly now? Have you set up a proxy server of any sort, or VPN?
Just some ideas around isolating the root cause. I hope this helps.