This package includes two of the STP-1 crossovers from Skytec, allowing you to split the signal run in from a single amplifier into seperate sub/bass and mids/highs. This enables you to effectively split the frequencies so you can connect a speaker designated specifically for bass/sub frequency and another speaker that's only playing mid/high frequencies. This gives you a safer connection of speakers, and reduces the risk of blowing speakers by putting too much sub/bass through a speaker that simply cannot handle it. .
eBay