This is bizarre. My friend has a pair of Ohm C2s that he bought back in college. I believe he graduated in 1981, a couple of years after I did. One of the mid-ranges on his C2s went bad. He brought to someplace in Providence, RI to have it replaced. Well we just pulled out his C2s about a month ago and the mid-range that was put in was not an original Ohm mid, but it looks EXACTLY like that phenolic tweeter. I did some research on this thing online and a place called Simply Speakers still carries these for about 25.00.
But what the hell is it doing in my buddy's Ohm C2 as a replacem