Sennheiser IE8 here, and yes default player sounds really tinny even with them and im in no way a basshead.

You just have to wait a little for proper EQ to emerge or buy a cheap Fiio E5 portable amp for 20$ either way the amp will make your westones sound a lot more like they should.

The Fiio E5 is very small so nothing you will notice in your pocket, will give better mids and cleaner treble and it even got a bass boost that work without sounding bloated.