Shown is a JBL E140-8 musical instrument speaker that was designed for bass guitar and PA use. I removed them to replace the foam air filter on the back of the speaker that had degraded and fell into the speaker's voice coil area. I contacted JBL on the procedure and they gave me very good instructions on the cleaning and removal of any foam particles. These are heavy duty low frequency speakers with a 18 5/8 lb. magnet structure. I can't replace the E140-8's because they are no longer produced and finding a company that produces a speaker with the same specifications is almost impossible. Fs = 32 Hz, Qts = 0.17 Update: I did find a low frequency driver with similar specs, BUUUUUUUUTTTTT, it's $519.00!!! UGH! I'll just stick with my 30 y/o speakers.