The heafty ferrite cores are the only way to reduce Emmisions of teh unite while in operation. Many manufacturers in order to meet FCC Class B requirement for consumer electronics implement ferrite cores (the cheapest way) to "pass" testing. If they where to remove cores IEEE1394 port would emmit badly (causing additional interference to other devices, like TVs) and PV-HD1000 will only comply to FCC Class A rules. Manufacturers strive to comply with FCC Class B rules in order to get better exceptance in the consumer market. FYI, Scandinavian markets have the most "tight" regulations in the World for consumer electronics. PC monitors manufactured in Japan bare one type of classification and are shipped to US. If monitor is bound to Norway or Sweeden it will undergo specific modification (internal magnetic buttons, board-level design changes etc) in order to meet more fierce Emissions/Immunity specs. You can use 4-4 Firewire virtually from any manufacturer but your unit will not comply to FCC Class B spec with it anymore. You may or may not experience any "unwanted" interference to other electronic/radio devices in your household. The quality of playback/recording of TU-DST5* and PV-HD1000 with any other cable will not be affected.