599) What is the real difference between a Hollywood flat and a hard (Broadway) flat? 600) How many Ohms resistance should a mic on a Clear Com Headset have? 601) What is the most common cause of Headsets sounding tinny? 602) What is the difference between HQ and Stage smoke? 603) If your headset sounds soft to you when you talk, but can hear others fine, and they can hear you, and changing headsets does not correct it, what can you do with the beltpack to correct it? 605) Pin 4 on a dual belt pack is for the common, 30VDC, Channel A or Channel B? 606) Headsets use 4 pin jacks, what is the maximum length of extension jumper allowed?