Tweeters????

Question

Hi, I have a pair of KLH 1230-SB's and the tweeters don't seem to be working on either of them.....the midrange and subs seem to be working fine.....the reciever i am using to power them is an AIWA AV-X270....They don't sound as good as i expected them to....usually i can figure out what's wrong with this type of stuff, but i can't figure this one out.....PLEASE help me!!!