Rainbow SLX DE LUXE

Hi, who can tell me or give tips how to adjust my tweeters from rainbow slx de luxe so that it doesn’t sound too shrill anymore have already switched from +3 to 0 the tweeters I placed on the armature under the heater fans,ca at the height of the side mirrors. they don’t shine any windows or windows, me they shine at shoulder height. have made over the hu equalizer settings, but despite that nothing reasonable could happen which of you ha t this ls,and how did you set it or place it,so for me the ht still sound too shrill HU Alpine 9830 R Front Amp Audison VR 209