I am trying to hook up a splitter for the incoming cable and internet service and trying to determine what device to connect to which of the outputs on the splitter. It happens to be a 3-way splitter even though I only need 2. I am going to have one output to the TV, and one to the cable modem. No set top box. What is the the best setup to prevent signal loss - especially for the internet - if the splitter has a 4 dB and two 8 dB outputs? If I should just get a two way splitter since I'm only splitting it that way, that's what I need to know as well.
My cable modem has a TV output so a splitter isn't needed.
If yours' doesn't then you need a bidirectional splitter. How much loss you can tolerate in the splitter will depend on how strong your signal is. A two way splitter like this one https://www.amazon.com/BAMF-2-Way-Splitter-Bi-Directional-5-2300MHz/dp/B0113JAN8K
doesn't make you chose which output is lower. If your cable provider supplies splitters than get one from them. That way they can't blame the one you bought for problems down the road.