I have noticed that each bell by cs bell co by their number sounds the same. Example.. if you had 2 number 30s and rang each of them, both would sound the same. number 20s the same way. You couldnt tell the difference. Were these bells all tuned to sound the same by number? I would like to know I have a number 4 and i heard another no 4 ring and it sounded just like my bell too.