Can anyone recommend what / where to get a replacement tweeter for the MarkBass Mini CMD 121P I did a gig last night and the sound tech noticed a lot of hissing from the tweeter. We turned down the treble to help it. After searching online this seems to be somewhat normal with the piezo tweeter. Can anyone advise me on a more permanent fix - like replacing the tweeter with a different kind (non- piezo) tweeter. Thanks!