Where to buy replacement Linaeum ET 6 tweeters?

My son has just fried both the Linaeum ET 6 tweeters in his Genexxa LX5 Pro speakers, purchased from Tandy in Australia about six years ago.Replacement units do not appear to be available here.The tweeters were manufactured in Japan. They were sold by Radio Shack in the U.S.as the Optimus LX5 Pro speakers. I cannot track down replacements being available from from either of the two company's web sites.

Can anyone help and point me in the direction of a source for a pair of these tweeters.

Many thanks.