First, make and incision in the outside-flap's lining and slide both of the speakers inside. If you want to be an overachiever, you can sew in a zipper or Velcro on the inside to close up the hole like I did
Make two overlapping flaps and sew them on either side of the slit to close up the incision for the speakers. Sew Velcro on either side of the flaps.
Cut a hole in the top part of the zipper and another in the outside pocket. To get the wires one hole to the other hole without make any holes in the lining, insert a straw in one hole and out the other. Then run a thick string, like shoelace string, to the other side and remove the straw. Tie the 3.5 mm audio jack to one end of the string and pull it through to the other side.
Now you have the mp3 connector inside the pocket and you are done! Enjoy your music and be proud that your speakers are hidden, completely discrete, while still crystal clear room-filling sound.
However, if you have a Jansport, it is easy to slip the speakers in the outside pocket, or secure them at the bottom of the bag and run the mp3 jack to the smaller outside pocket.
Another option is to install the speakers in a three ring binder. Just put the speakers inside and use cardboard or tape or some combination of the two to seal the edges. Make sure to make hole for the sound vibrations to get through.