To use a boombox, click on About Me on your task bar. Then click on the Consumables button (it looks like a potion bottle). You can then add a boombox to your Quick Item buttons. To do that, select which Quick Item button you want to assign it to (1-4) by clicking on the Quick Item # in the lower part of the windown. Then click on the boombox. It will be added to that Quick Item button.