An HDMI splitter is built to show the same picture on every screen, which is exactly what you are seeing now. To stretch one picture across two screens, replace it with a video wall processor whose input format matches your player, or drop the splitter and give each screen its own player. A worked example sizes the content for the processor route.
Your Android box feeds two 55-inch TVs through an HDMI splitter, and both TVs show the same picture. You wanted one picture stretched across both. The splitter is doing exactly its job: it puts the same signal on every output, so the same frame arrives at each TV. To turn two screens into one big display you replace the splitter with a video wall processor that cuts one frame into two feeds, or you drop the splitter and run a player per screen. This page compares the three arrangements, names the spec to check on the processor, and sizes the wall content with real numbers.
Why both TVs show the same picture
An HDMI splitter takes one input and sends the same signal to every output. Nothing on the Android box or on the splitter rearranges that: the same frame reaches both TVs, pixel for pixel. One source split into two different halves is not a setting you can find, because the duplication is what the splitter is built to do.
If both TVs should keep showing the same picture, the same promotion in a window and behind a counter for instance, keep the splitter; it is the right box for that job.
What a video wall processor does
A video wall processor takes one HDMI input, cuts the frame into pieces and sends one piece to each output. On a 2x1 wall each output feeds one TV. Typical 2x1 units output 1920 x 1080 at 60 Hz per port, some adding 1920 x 1200 as a second option.
The spec that decides the purchase is the input list, because two classes are on sale. Units built for 4K splicing list input support up to 3840 x 2160; cheaper units cap input and output at 1920 x 1080. Read what your Android box lists under its display settings and match the processor class to it. If content will cross the seam where the two screens meet, shortlist models that offer bezel correction and check the feature on the spec sheet.
The processor is a small box that wants an outlet and a spot behind the screens. Plan it along with the screens themselves: wall brackets and power supplies cover the mounting and power side.
Splitter, processor or two players side by side
| HDMI splitter | Video wall processor | Player per screen | |
|---|---|---|---|
| Picture on each TV | The same picture | One picture cut in two halves | Each TV its own picture |
| What the source must produce | One frame for both TVs | One frame sized for the whole wall | One frame per TV |
| Feed arriving at each TV | The source's own output | 1920 x 1080 per port | That player's own output |
| Spec to check | Number of outputs, cable length support | Accepted input formats: 1920 x 1080 or up to 3840 x 2160 | Player content and schedule |
| Middle of the wall | Identical picture both sides | The picture crosses the bezel | Two independent pictures |
| Extra hardware | The splitter you already own | One processor | A second player |
Where each arrangement wins
- The splitter wins when both TVs should show the same picture. You already own it, the cabling exists, and no content has to change.
- The processor wins when one picture must span both TVs. The canvas becomes nearly twice as wide as one screen, which is the difference between a poster and a banner.
- Two players win when the TVs need different content or different schedules. Each screen updates on its own and there is no seam to design around. A signage display with the player built in folds the player into the screen itself. Connecting the Android box to such a display is a dead end, because the HDMI port on an Android signage player is an output; why HDMI input on Android signage players rarely works explains that trap. When two players run one coordinated program, how players stay in step on a video wall covers the timing.
If the wall size itself is still open, start with what size digital signage screen you need, which covers viewing distance and letter height from scratch.
Example: one picture across two 55-inch screens
Inputs. Two 55-inch 16:9 TVs side by side, the setup in front of you. Per-TV feed 1920 x 1080 at 60 Hz, the standard 2x1 processor output class. Input class A accepts 1920 x 1080; input class B accepts up to 3840 x 2160; both classes as listed above. Letter-height rule: 30 ft of viewing distance per inch of capital letter height, 20 ft per inch where people read while walking past (FHWA planning figure). A 16:9 screen is 16/18.36 of its diagonal wide, where 18.36 = √(16² + 9²).
The rule in words. Wall pixel pitch equals wall physical width divided by canvas width in pixels. Letter height on the wall equals canvas pixels divided by pitch, and every inch of letter height buys 30 ft of reading distance.
Arithmetic.
- One TV: 55 × 16 / 18.36 = 47.93 in wide. The wall: 2 × 47.93 = 95.9 in wide, bezels aside.
- Class A canvas: 1920 px / 95.9 in = 20.0 px per inch. A capital drawn 40 px tall prints at 40 / 20.0 = 2.0 in and reads from 2.0 × 30 = 60 ft, or 2.0 × 20 = 40 ft for fast reading.
- Class B canvas: 3840 px / 95.9 in = 40.0 px per inch. The same 40 px capital prints at 40 / 40.0 = 1.0 in and reads from 1.0 × 30 = 30 ft. Drawing it at 80 px returns the 2.0 in letter and the 60 ft reach.
Result. The 1080p-input class gives the wall 20.0 px per inch, so its smallest practical capital is 20 px: 1.0 in on the wall, read from 30 ft (20 ft fast). The 4K-input class doubles the canvas density to 40.0 px per inch.
Decision. Take class A when the nearest reader stands 30 ft or farther away and every capital is 1 in tall or taller on the wall. Take class B when people read from closer in, or when the design carries detail finer than 1 in on the wall. One check before ordering class B: confirm the model accepts 3840 x 1080 input for a 2x1 wall; if the list shows only standard 16:9 formats, set the player to 3840 x 2160 and ask the seller how its 2x1 mode crops that frame.
The decision
Recommendation: Keep the splitter if the two TVs should show the same picture; duplication is its job and your setup already does it. Buy a 2x1 video wall processor only when one picture must span both screens: pick the 1920 x 1080 input class for content read from 30 ft or farther, the 3840 x 2160 input class for closer reading, and match the input format list to your Android box's display settings before you order. Run a player per screen when the two TVs need different content or schedules; that also removes the seam and the processor.
Questions
Does an HDMI switcher solve this instead?
No. A switcher does the opposite job to a splitter: it connects several sources to one screen and lets you pick which one is live. A splitter takes one source to several screens with the same picture on each. A video wall processor takes one source and crops the frame across several screens. For one picture stretched over two TVs the processor is the box; the switcher changes nothing about duplication.
Will a 1080p feed look soft on a 55-inch TV?
The TV scales whatever it receives up to its own panel, so a 1920 x 1080 feed fills a 4K panel with no black bars. Sharpness is judged from where people stand: a wall read from 20 ft or farther hides the upscale, and the real limit is the canvas resolution the processor accepts, which is the arithmetic in the example above. Feed each TV 1920 x 1080 and put the budget toward the input class.
Do both screens have to be the same size for a stretched picture?
Yes, when a processor cuts one frame in two: the two halves carry the same pixels, so a smaller screen prints them smaller and anything crossing the seam changes scale. Matched panels of the same size keep the picture even. Two independent players lift the restriction, because each screen then shows its own full frame and the sizes can differ.
Planning information, not legal or engineering advice. Rules differ by place: check codes and permits with your local authority and your licensed trades.