And if EQ-ing the horns , new prams and drivers still won't do it for you....you can do like some here have done and add a tweeter by-passed in at 3k or higher. This tweeter OG mentioned a few weeks back is one I have used with 511/806 (home application).
Vifa BC25SC06-04 1" Textile Dome Tweeter 264-1028
(BTW-never felt a need to add tweeters to EQ'd 808 b's / 802 g's)