Originally Posted by rick240
To build on, and contradict what BeeMan said, you will want to run all of the wires in the wall. Be ready for dry-wall repairs as part of the install (i.e. budget for it).
What, miss a chance to contradict the BeeMan?
No contradiction. FWIW, I ran my wires without any sheetrock damage and in most cases, everybody can do the same. As always, it depends on speaker placement such as over windows and doorways because of headers getting in the way. Pretty much, unless dealing with a concrete floor with no attic access, everything else can be done damage free. Think 1/2", 18" long drill bits that can be had for $50-$75. Wall openings next to the floor can be easily made for access to the floor plate for drilling purposes and covered again with a solid matching color cover plate to match your existing wall outlets (or painted to match wall color) for later access.
Wall top plates are easily accessible from the attic if one is dealing with concrete floors. A word to the wise, this day and age, eighteen inches of insulation is miserable stuff and moving it around messes with the R-rating (integrity) of the insulation moved. FYI, corded drills are better than battery operated drills, more torque for drilling old dried wood.
If need be, fishing walls can be done with standard electrician fishing lines, purposed to pull wire through conduit.
If in a convenient location, the removal and replacement of existing electric junction boxes, a huge pain, will alleviate the need to create additional access openings and gives one immediate access to the floor plate for the purpose of drilling an access opening to run the wire under the house. All easily doable if one is capable.
Hope the above gives folks some DIY ideas on putting wires in the wall.