You should try to contact JVC and get an answer from them.
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I have a package of 25 Memorex DVD-R 4X media and there is this warning on the package:
''Using new recordable discs (4X DVD-R) in 1X-2X Pioneer-manufactured DVD drives and DVD recorders may cause damage to the DVD drive or recorder and possibly to the loaded 4X disc.
The source of the problem is a firware ''bug'' in certain DVD-R/RW drives and recorders, and not with the media itself.''
And then it lists a number of Pioneer products that are affected.
They show a link to:
www.pioneerelectronics.com/hs/
Your JVC may have the Pioneer drive installed.
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Added note.......high speed media will not record faster on the JVC. Those type devices are set to record at 1X speed.
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I just purchased a JVC dual DVD-VHS player with dubbing. JVC says I must use discs that conform to lx-2x speed DVD-RW players or I could harm the player. If a disc has a higher speed, ie: 8x or more, will that work or does it have to be no larger than 2X? Also does anybody know the difference between DVD-RW and DVD+RW?
Thanks. I really could use some help here.

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