HDMI Splitters: Everything You Need to Know!

Flexibility is good when it comes to your home theater system. There are all kinds of tools, especially surrounding HDMI, that allow you to do clever things like stream an HDMI signal wirelessly (our article) or even extract the audio from an HDMI cable (again, our guide) so that you can send it to the speakers of your choice. One neat tool that some find useful is an HDMI Splitter.

HDMI Splitters allow you to take one video source and split it into multiple locations. This may mean running a cable signal to two rooms, or it may mean connecting ten or more TV screens together. There are limitations of HDMI splitting, but for the most part, they do exactly what you’d expect.

There are a lot of questions about HDMI splitters – not to be confused with HDMI switches which we talk about elsewhere – including how they work, whether they’re okay to use, or whether or not they degrade the video quality. Here are some very common questions and answers about HDMI splitters.

How HDMI Splitters Work

HDMI Splitters, such as this one from Amazon, are a handy tool that can save you hundreds of dollars (or more!) There are certain situations in a commercial space like an office or restaurant where the owner may want a dozen or more screens all showing the same thing, and although HDMI Splitters can do this job (and do it well), what we’re going to discuss today is the smaller-scale of HDMI Splitting.

There are at-home uses for HDMI splitting that can save you, the normal consumer, a bundle if you simply want to get your content onto different screens. For instance, if you have a home theater room and also a bedroom TV; if you have a rec room, a den, or living area that all have screens–any case in which you need to get the content you want on both screens at once is where an HDMI Splitter comes in handy.

This can be really convenient if you have a service like DISH Television or Cable TV that only goes to one place, for instance, one cable box. Services like this charge you for a second cable box, and so simply splitting that signal to two places can save you literally hundreds of dollars in hardware and subscription costs.

But unlike other cables, HDMI splitters have to do some heavy lifting. HDMI signals carry audio and video…sometimes very high-quality audio and video. And more than that, they also carry two-way communication between the screen and the content source. This is accomplished using signals referred to EDID (which we have more info on here).

Long story short, there are some things that need to go right for HDMI splitting to work. It should be no surprise to you that there are powered HDMI splitters like the OREI 4k 1 x 2 HDMI Splitter (on Amazon). These are really small, specialized computers that have to reproduce the HDMI signal (high resolution, EDID, and all) before sending it forward to two devices.

If you have questions about quality, lag, and how these devices can affect your setup, you’re not alone. Let’s dive in.

Pros of HDMI Splitters

• Cost Savings – HDMI Splitters can allow you to take a signal from a content provider you’ve paid for, like the cable company, and split that to multiple screens. This means that you only need one subscription and cable box to, for instance, display a big football game on the Television in your main room as well as the one in the bedroom.
  
  For a device that can easily cost less than a hundred dollars, HDMI splitters can pay out very quickly if they can help you avoid another contract or subscription cost over time.
  
• More Simplicity and Control – If you’re here because you’re managing more than one large, nice screen in your home, then you know what a hassle it can be to wire up home theater systems in general. When it comes to getting all the content in the right place, it’s hard enough for one primary screen which may require a surround sound system, a receiver, and other hardware.
  
  With an HDMI splitter in the mix, you now have a new tool that allows you to do some very interesting things. Consider pairing your splitter with a few Wireless HDMI units (more details on that in our post here). With these tools in play, you could now run all your content to one place, one closet with all your hardware for instance, which simply broadcasts the HDMI signals out wirelessly.

Cons of HDMI Splitters

• Resolution Limits – One drawback to using HDMI splitters is that the splitter itself limits how the HDMI’s EDID info can be used. We have another article explaining EDID in more detail, and it’s also mentioned above, but without going into too much detail, the main idea is that the screen you’re linked up to, phones home to the HDMI source to tell it what resolution it is.
  
  If you’re using a splitter and sending a signal to two screens, obviously they may not be the same resolution! Even powered HDMI Splitters stumble at this step. With two different EDID resolutions being reported back, the splitter has to adjust the resolution down to meet the lowest one. This means a splitter hooked to a 4k TV and a 1080p TV will be sending 1080 to both of them.
  
• Cable Interference – Because you’re using a splitter specifically to run the video somewhere at least somewhat distant from the source, you’re probably using extra-long HDMI cables. HDMI cables’ maximum effective length is around fifty feet, and after that, the length of the cable itself can start to allow interference into the signal. If you’re planning on splitting a signal and running it across the house, that fifty feet adds up quickly.

How HDMI Splitters Deal with Quality and Lag

If you’re considering HDMI splitting, then maybe you’ve done a lot of thinking around your home video/audio set up already, and it won’t be surprising for you to hear that the quality of each component in the chain is critical.

Quality

If you want to stream a 4k video source to your TV, your TV has to have a 4k panel, and the HDMI cable has to be able to carry 4k video. None of these are really a problem now that 4k is basically standard.

However, when you split a signal, you’re introducing another piece of hardware–another link in that chain of the video being managed. There are 1080p splitters out there and, you guessed it, they’ll downgrade your 4k video stream down to 1080 if you use them.

This isn’t too hard to avoid: simply look for a splitter that is rated for the output that you need. Earlier in the article we discussed how a splitter will be somewhat limited by the least capable downstream screen, but this hardware discussion is something different. If you’re streaming 4k to two 4k monitors, the splitter has to be rated for 4k for it all to work.

Other than that, as long as you’re using a powered option there should be no other quality issues to worry about. There may be some lag or latency that you will most likely not notice, but there aren’t any other drawbacks of splitting a signal from a video quality standpoint.

Lag and Latency

When it comes to Lag, aka Latency, the HDMI Splitter can add significant lag, but that’s really only a problem if the unit is non-powered. If you’re using something like the Enbuer 1×4 HDMI Splitter (on Amazon), or basically any splitter that connects to a power source, you can be confident that it’s got the right internal equipment to duplicate the HDMI signal without any extra processing or funny business that would slow it down.

There’s no getting around the fact that the HDMI splitter is a new link in the chain of the video signal, so it is going to add some adidtional delay, but with a powered unit this delay is no more than a couple milliseconds (ms). A delay like 2ms is really nothing to worry about. That’s just two frames of a 60hz signal. If these terms mean nothing to you, then don’t worry: that means that you’re exactly the type of consumer that doesn’t need to worry about any of this.

For the intense gamers out there, you’ll need to look for a splitter that specifically advertises the refresh rate you’re looking to match. If you want to split to 120hz screens, that means you’ll need all the other tools to do that right, and the splitter, as discussed in the quality section, has to be as capable as all the other components in the chain.

Summary

As you can see, there are several details you have to get right when using an HDMI splitter, but the good rule of thumb is to use a powered unit whenever you can. If you make sure you cover that, then the other details should all fall into place.

In addition to getting a powered unit, you may need to verify the splitter is verified for the resolution you’re hoping to use, while also keeping in mind that the downstream video receivers (your screens) will need to have that resolution as well or the signal will be downgraded at the splitter.

In general, though, these are handy tools that can expand your home theater system at a very fair price. Splitters allow you to save money and also have more options when it comes to your home theater system.