The Crossover - Brain of your Loudspeaker System | Audioholics
400w Speaker Crossover 2 Way Audio Tweeter Bass Filter Frequency Divider | Fruugo JP
Crutchfield Bass Blockers Pair of inline high-pass filters (5000 Hz cut-off) for tweeters at Crutchfield
Low pass filter on tweeter | AVS Forum
2PC 3 Way Speaker Crossover Filter 150W Cabinet Accessories For HiFi Tweeter Car Woofer Home Theater Karaoke Studio DJ Audio - AliExpress
Midrange and Tweeter wired in series + inline High pass filter before tweeter? | DIYMobileAudio.com Car Stereo Forum
Non-BO tweeter seems to have the hi pass filter (passive crossover) attached right to the tweeter. Makes for an easy switch to an active crossover since you can reuse the existing wiring