Which direction will you be coming from? As has been said before, BBR is at the bottom level of the Manulife Center.
If you are taking the Yonge line, get off at Bloor and walk one street west, to Bay. The Manulife Center is quite large and has lots of other shops. From the outside, you will see Varsity cinemas, William Ashley.
If you are taking the University line, get off at Museum and walk east along Bloor to Bay.
If you are taking the Bloor/Danforth line, get off at Bay and walk south to Bloor.
It will be really hard to miss the Manulife Center if you are anywhere close to it.
I can't help you with directions to the other places until I know where you are coming in from.
The other posters are right, the headphone area is quite noisy, but they are all out on display on a wall, giving you the chance to play with them all at once. You would probably be able to narrow your search here just based on comfort and price, and then look for a quiet place for your final decision.