I just released an EP so I'm not gonna change anything on those songs now, BUT I would really like to know what I could improve on in the future! These are pretty poppy, and you'll pick up on it right away, so I'm shooting for the most hi-fi sound possible!

Sampler | Scott Ogilvy

By the way I'm fully aware that they have a bit too much low end mud (around 300-500Hz)
What other problems are there?

Thanks a lot!