Never done this before, but I've read people who have. The idea you propose shouldn't be a problem. Here's what I remember...
1. Good quality fishing wire is key, especially if you're battling insulation. Make sure what you buy is long enough for your needs. I'd look for this at a place like Home Depot (not sure where would be best in Toronto), or online retailers such as
www.partsexpress.com or
www.monoprice.com or
www.techtoolsupply.com.
2. Triple-check your drills/pulls... avoid studs and wires!
3. Don't run audio cables along the same path as other electrical cables. This can cause interference, and is usually not to code. (Basic rule of thumb -- high-current w/ high-current, low-current w/ low-current). Obviously shielded, in-wall rated wiring helps here as well.
This might also prove helpful.