Speaker cabins for DIY, simple to build

I'm trying to get my own speaker cabins built, but I don't know which ones to build. I'd like a three piece set, top, mid and bass. For the top, I know what to get and do, but the mid and bass is confusing. I heard of double W-bin cabins and Karlson principles, but one promised me they are not easy-to-build. Anyone does have easy schemes for these or other power sets?

Thanks in advance...