Welcome to the forum!
The capabilities of that sub are here: http://www.klipsch.com/kp-115/details#description
I don't know what the 'B' designation is for. This speaker is pretty simple to troubleshoot really. If you are getting no sound from the speaker, remove the driver, and connect your speaker leads to it. If you still don't have sound, you have a dead driver. Call Klipsch and see how much for a replacement. If they don't have one, you will have to look for one. You can post a message in Garage sale here, etc. The driver is a K-48-K.
Good luck!