no it will be all most same ..as main domain have good back link I think

Thanks, anyone else got anything to chime in. Thanks

I think subdomain is the same as pages or posts so should have the same backlink juice as the domain.

A subdomain has nothing to do with the main domain. PR and authority does not just magically flow to pages on a domain. It flows through links.

Just think of a sub domain as another page on your main domain. It doesn't share PR or anything like that. It will need to be worked on.