WE ARE WAITING FOR SAMPLES FROM JERN JERN http://jernspeakers.com/jern12-xf-loudspeaker/They are unfortunately made of iron so they will ring like a bell. The speaker is even shaped like a bell so not very good design.
Theres no response curve provided on their site, they have -6db @65 hz which is terrible and are overpriced. Best to be avoided.