answer is Yes, you can. Read my long post about IELTS here.
First time i got almost like your result:
listening 8, reading 6.5, writing 6.5 and speaking 7
Second time i got this:
listening 8, reading 8.5, writing 7 and speaking 7.5 - which is CLB9
And this is a tip how. It is long but take the advice, you couldn't go wrong by trying.
http://www.canadavisa.com/canada-immigration-discussion-board/ielts-preparation-t388867.0.html