ADTech, you are correct about Terminating Resistors. Most people don't bother to use them.
Ratman, why don't the OP just use a 4 way splitter? I never thought a Cable Modem needed a strong signal. Just asking.
Gar face, I got my splitters from tselectronic.
TV - LG 65B7P OLED / Receiver - Yamaha RX-A1040 7.2 / Blu Ray - Oppo BDP-83 / Turntable - Technics SL-3300 / Cable Box - Comcast X1 V4 4K /L & R Paradigm Studio 20 V3
Center - Paradigm CC-470 V3 / 4 Surrounds - Paradigm SA-15 V3 In Walls
Subwoofer 1 - Sunfire HRS-12 / Subwoofer 2 - Paradigm PW-2100