The Crossover Design Cookbook Chapter 1: Simple Crossovers
Amazon.com: ACEIRMC 2pcs 400W Adjustable Multi Speaker Treble/Bass 2 Unit Audio Frequency Divider 2 Way Crossover Filters Updated Version (2pcs) : Electronics
Crossovers
200W 400W Speaker Subwoofer Crossover Audio 1 WAY Filter Frequency Divider Bass | eBay
Understanding + modelling passive filter (crossover) circuits: Component position and effect - Electrical Engineering Stack Exchange
LCR-RC
FIR Crossover Design: FIR Designer software for speakers - Eclipse Audio
Current Source Crossover Filters | audioXpress
Audio crossover filter - MATLAB
Best Active CrossOver Filter Circuit for Speaker Boxes
Speaker Crossover Filter — Joseph Conley.com
Linkwitz–Riley filter - Wikipedia
A Bessel Filter Crossover, and Its Relation to Others
An Overview of Filters in A Crossover Network | GBC ET Technician