Video Wall Setup

MultiMon has two ways to make several monitors show one picture: Split and Span. Both are driven from the mode dropdown in the main window.

Split mode

Split takes one source and cuts it into a grid of rows and columns, then sends each cell to one of your outputs. A 2×2 grid is the default.

Setting the grid

When the mode is Split, the main window shows rows and columns fields. Set them to the shape of your wall — 2 rows by 2 columns for a square of four screens, 1 by 3 for a horizontal strip, and so on.

Mapping outputs to cells

Each monitor slot takes a row,col mapping, which says which cell of the grid that display shows.

2 rows x 2 columns

  1,1 | 1,2
  ----+----
  2,1 | 2,2

A monitor that is left without a cell — more screens than the grid has cells, or a mapping that points outside it — stays black rather than showing the wrong slice.

Letting MultiMon pick the grid

Tick Auto (by screens) and MultiMon derives a near-square grid from the number of screens it detects: four screens give 2×2, six give 2×3, nine give 3×3. Untick it to type the rows and columns yourself.

Press Identify screens first: numbered overlays appear on every display so you can be sure which physical screen you are assigning before you commit the mapping.

Because Split is one source cut up, every cell comes from the same decode and the same clock — the sections are inherently in sync with each other.

Span mode

Span takes one source and samples it across every display MultiMon detects, as a single continuous canvas. There is no grid to configure.

Two things to know before you use it on a show:

• There is no monitor selection. Span uses every display it finds, which includes the screen of the control machine itself. If you are running from a laptop, its own panel becomes part of the wall.
• Each screen gets an equal share of the picture — per screen, not per pixel. A 4K screen and a 1080p screen each take the same slice of the source, so a wall of mixed resolutions will not line up geometrically. Match your screens, or use Split and map the cells yourself.

Span, like Split, is one source, so it too is inherently in sync.

Choosing between them

	Split	Span
Layout	An explicit rows × columns grid, mapped per output by row,col	Across every display MultiMon detects, one continuous canvas
Configure	Rows and columns (or Auto (by screens)), and a row,col per slot	Nothing — there is no monitor selection
Mixed resolutions	Cells are yours to map, so you stay in control	Equal share per screen, not per pixel — will not align
Unmapped screen	Stays black	Not applicable — every screen is used
Sync	Inherent — one source	Inherent — one source

If you want a different source on each screen instead, use Individual mode and its Sync (frame-lock same-length clips) checkbox, or — when every clip is a HAP file — Hap mode, which puts one HAP clip per monitor on the one shared clock. See Video synchronisation.

Performing

Press F11 to enter perform mode; Space pauses and resumes; Esc exits. Save the layout with Save project to a .mmproj file so the wall comes back exactly as you left it.