Amazon.com: DS18 XM6LD 6-way Active Crossover - High/Low Pass, 2, 4, or 6 Channel Selector, with Remote Subwoofer Control - Perfect Frequency Distribution System Ensures Clarity and Peak Efficiency, BLACK : Electronics
EQ901 PS Equalizer & Active Subwoofer Crossover Upgrade Replacement for BOSE 901 | eBay
Active Subwoofer Crossover
Rolls SX45 Stereo Two-Way Mini Crossover w/Sub Output
CX311 – 2way Crossover with Subwoofer Out – ART Pro Audio
Amazon.com: 4 Way Active Crossover 15V Audio Signal Line Driver Bass Control Audiopipe XV-4-V15 : Electronics
Amazon.com: Planet Audio EC20B 3-Way Electronic Crossover with Remote Subwoofer Control : Electronics
Source 3-Way Active Crossover With Remote Control, Audio Crossover 3-Way on m.alibaba.com
SPL Crossover Active Analog 2-way Crossover (Silver)
RDL STCX2S Subwoofer Crossover Filter | Full Compass Systems
Crossover – SPL
JL Audio CR1 Prototype subwoofer specific precision active Crossover audiophile component | Reverb
XV-3-V15 BP 3 Way Active Crossover with Bandpass Filter
CR-1 Active Subwoofer Crossover - Electronics - Home Audio – JL Audio