Cable splitters are used to connect multiple TVs, computer monitors, or other devices to a single signal source. There are differences between the various types of splitters, but a few general rules apply to them all. Splitters only go from one input to multiple outputs; if you need to go from multiple inputs to one output, you need a switch instead.
When a signal goes through a splitter, it is divided and becomes weaker. Imagine an HDMI splitter as an example. Modern HDMI cables are capable of a 4k signal, which works fine if you are using a single HDMI cable by itself. However, say you use a 4-way HDMI splitter to run four cables to four TVs. Each signal would only have half the normal strength so none of the TVs will have 4k quality.
Because the signal is evenly divided, the signal will become weaker for bigger splitters. A 2-way splitter will have signals with ½ the normal strength, a 3-way splitter will have ⅓ the normal strength, etc. This is true even if you are not using every port on the splitter. When a cable splitter is powered on, the signal is split between every port on the unit even if not all of them are in use. For example, if you have a 3-way splitter and are only using two of the ports, each of those two lines will still only have ⅓ the normal signal strength.
Coax Cable Splitters
Coax cable splitters are used to connect multiple TVs to a single coax line. These splitters are made with F-type female ports, the same type of screw-on connection seen on the backs of most TVs.
Coax splitters can be rated for different Radio Frequency (RF) ratings, measured in MegaHertz (MHz). The MHz range on the splitter determines whether it can be used for antenna, satellite, or both. Antenna signals run from 5 - 900 MHz. Satellite signals run from 950 - 2350 MHz. The exact MHz will depend on the TV stations in your area and how they send out their signals, such as whether signals are transmitted in high definition or not.
Power is supplied directly through the coax line; coax splitters do not need to plug into a wall outlet. Any port on a coax splitter that transmits power will be marked “Port Power Passive”. Some coax splitters can send power through every port while others have just one port that is power passive. If you need to send power through multiple ports, make sure to select a coax splitter that can do so.
Headphone splitters for 3.5mm cables are fairly common and come in two main varieties, 1 male to 2 female and vice versa. The 1 male to 2 female version is typically used to plug two sets of headphones into a single device. Just stick the male side into your MP3 player, computer, television, or whatever else you are using to change your single headphone jack into two. The 2 male to 1 female version is not as common and is frequently used to adapt standard 3.5mm cables into splitters.
3.5mm splitters also double as adapters to other types of connections, such as ¼”. For this variant, it is important to check whether you need a mono or stereo splitter. The mono splitters tend to be color coded (similar to an RCA adapter), making it easier to tell the two apart.
Video splitters are commonly designed as a box that other cables connect to. Smaller, pigtail splitters are available but generally only as a 2-way splitter. Anything bigger follows the box design. Below is an example of a 2-way HDMI splitter (left) vs. a 4-way HDMI splitter (right).
HDMI is one of the most common splitters today with most televisions, computers, and other devices being built with HDMI as the default audio/video port. HDMI can transmit small amounts of power, so small-scale HDMI splitters can work on their own without any external power for short distances. When hooking up an HDMI splitter and it does not work, it probably just needs more power than the HDMI cables alone can provide. HDMI splitters are equipped to use either a USB cable or a wall outlet charger to provide extra power. Other types of splitters, such as VGA, typically cannot provide power through the video cables and will always require an external power source.
When using a splitter to connect multiple monitors to a computer, keep in mind that the signal source is the same for every monitor. This means that the images will be the same on all the screens you hook up. A splitter can only be used to duplicate the screen. If you are trying to extend the screen, to do different things separately on multiple monitors, you cannot use a splitter. You must use a separate signal source for each monitor (i.e. a separate, independent video cable for each monitor).
ShowMeCables offers a few devices referred to as “ethernet splitters”, but these are not splitters in the traditional sense. An ethernet signal cannot be split like an audio or video signal. These devices are designed to be used in pairs to run a single ethernet line through walls instead of two. Details can be seen in the video below.
Although ethernet signals cannot be split, a similar effect can be achieved with a network switch. Network switches technically only send one signal at a time, but the signals are sent so fast that multiple signals transmit back and forth in a fraction of a second. A network switch allows users to hook multiple devices to the Internet through a single wall port. They can also be used to network multiple devices together, such as connecting a single printer to multiple computers.