A golf simulator floor projector can avoid a ceiling installation, but the BenQ LK830ST still needs the correct lens height, distance and protective housing. Its short lens is useful near the screen. Its fixed vertical offset is the less obvious constraint: a level projector on the floor naturally starts the image above the lens.
This guide uses the LK830ST as a specific 4K example. The calculations come from BenQ's published 0.496 throw ratio and the LK830ST column of its installation table. They are planning calculations, not a tested housing recommendation. Start with the BenQ LK830ST only if the resulting position works with your screen and hitting area.
First distinguish the projector from its floor enclosure
A protective floor enclosure holds the projector and helps keep it out of direct impact. It does not change the projector's throw ratio. It can also raise the lens, move the lens opening forward or back, and restrict the cable route. Those changes belong in the installation drawing.
Before purchasing a housing, obtain its compatibility information for the exact projector and its internal lens-height specification. BenQ lists the LK830ST body at approximately 10.99 inches wide, 4.74 inches high and 9.03 inches deep. Those dimensions are only a first screening check; airflow, lens opening and connector clearance need confirmation too.
A general-purpose projector box should not be assumed safe against golf-ball strikes, rebounds or club contact. Check the housing maker's stated use and installation instructions. Do not place an unprotected projector on the turf and treat a short-throw label as protection.
The overlooked measurement: the screen's bottom edge
For a level, upright LK830ST projecting its full optical height, the manual's table shows a lens-to-image-edge offset of approximately 14% of image height. For example, its 100-inch 16:9 entry lists 1245 mm of image height and 174 mm of offset: 174 ÷ 1245 is about 0.14. This is how the published 114% full-height offset translates into a room measurement.
Use the finished floor as a common reference. Let H be the full optical image height and L the center of the lens above that floor. The starting geometry is:
- Image bottom height = L + 0.14 × H.
- Required lens height = desired image bottom height − 0.14 × H.
If the calculated lens height is below the floor, a level upright installation cannot put that full-height image where you want it. Raising the projector makes the image start higher. Tilting and digitally correcting the picture creates a different installation that must be tested; it is not the same calculation with an automatic guarantee of coverage.
| Full optical image height | Offset above lens | Lens distance to screen | Image bottom with lens 6 in above floor |
|---|---|---|---|
| 6 ft / 72 in | 10.08 in | 5.29 ft / 63.49 in | 16.08 in |
| 7 ft / 84 in | 11.76 in | 6.17 ft / 74.07 in | 17.76 in |
| 7.5 ft / 90 in | 12.60 in | 6.61 ft / 79.36 in | 18.60 in |
| 8 ft / 96 in | 13.44 in | 7.05 ft / 84.65 in | 19.44 in |
The 6-inch lens height is an example, not a specification for a particular housing. Distances use H × 16 ÷ 9 × 0.496. For a full-height 4:3 or square picture, the unused side portions of that optical frame need to be handled by the format settings and surrounding installation. See the LK830ST Screen Fill guide for that separate setup task.
Worked example: a raised screen can fit; a floor-level picture may not
Suppose the visible picture is 7 feet tall and its bottom begins 18 inches above the finished floor. The LK830ST's offset estimate is 84 × 0.14 = 11.76 inches. A level upright lens therefore needs to be about 6.24 inches above the floor: 18 − 11.76. Its estimated lens-to-screen distance is 74.07 inches.
That provides two concrete numbers to compare with a housing drawing. It does not approve the whole bay. The picture's top is 102 inches above the floor, and the screen system must be designed to handle the area below the visible picture. Confirm the enclosure's lower protection and rebound management rather than raising a screen solely to satisfy the projector.
Now keep the same 7-foot picture but put its bottom only 4 inches above the floor. The calculation becomes 4 − 11.76 = −7.76 inches. The required lens position is below floor level. A larger floor enclosure cannot fix that level-installation geometry. Revisit the image placement, test a different approved configuration, or evaluate a ceiling installation.
Can an inverted ceiling mount resolve the height conflict?
With an inverted, level ceiling installation, the offset sits above the top of the full optical image. The starting lens height is therefore:
Lens height = image bottom height + 1.14 × image height.
For the 7-foot-tall picture beginning 4 inches above the floor, the estimate becomes 4 + 1.14 × 84 = 99.76 inches. Under a 108-inch ceiling, the lens center would sit about 8.24 inches below the ceiling. The mount and projector still need to produce that lens position with the required body and ventilation clearances.
This is why ceiling height alone does not establish whether a projector fits. Mark the lens center, image edges and actual bracket geometry. The Simulator Calculator can help organize the wider room plan; use the manual and a real projection test to confirm the final mount.
Place the housing in the complete golf layout
Draw the screen plane, ball position, stance area and floor housing to scale. Include its full width and depth, not just a dot representing the lens. Consider every intended player and both handednesses where applicable. The box must not interfere with the stance, club path, walkways or the launch monitor's required working area.
A housing between the ball and the screen also occupies space near the ball's route and possible rebounds. The projection calculation cannot prove that placement safe. Use the screen, enclosure, housing and launch-monitor instructions together. If the hardware has no documented compatibility or appropriate impact protection, resolve that uncertainty before buying it.
Plan access as carefully as placement. You need a protected signal and power route, unobstructed cooling and a way to remove or service the projector. Turf thickness and the finished hitting surface can change floor references, so take final measurements after those heights are known.
Run one useful test before making the location permanent
- Mark the calculated lens location and target image edges. Confirm which point in the housing represents the actual lens center.
- Test the projector at that position with no players hitting into the screen. Start level and square to understand the optical fit before applying correction.
- Check a grid, circles and small text across the picture. Look for clipping, distorted shapes and uneven focus, including the application menus.
- Set the intended screen format and source output. Verify the picture again after restarting the source and switching to the simulator.
- Confirm the final protected layout against the hardware instructions before normal play. Record the lens position, picture edges and settings so the installation can be reproduced.
When a floor-mounted LK830ST is worth pursuing
It is a useful option when ceiling mounting is impractical, the calculated picture height works, a compatible protective housing is available, and the box fits outside the required swing and equipment space. It is less attractive when a floor-level image is essential, the housing creates an obstruction, or you expect to move the projector without repeating the alignment check.
Compare the complete cost: projector, verified housing, cable protection and any screen or flooring work. If the required lens position suits the LK830ST, check its current configuration and availability and bring the dimensions into the Simulator Builder. If your available mounting point is farther back, the AK700ST versus LK830ST guide explains the optical alternative.
Once the housing and optical position work, the LK830ST buying review checks the other purchase questions: the 4K signal chain, useful image detail and the effect of screen area on brightness.
Questions about floor projection
Does “ultra short throw” mean the LK830ST sits against the screen?
No. Calculate with its 0.496 ratio. At typical simulator sizes the lens is several feet away, even if a shop groups it under an ultra-short-throw category.
Will Screen Fill correct the wrong lens height?
Screen Fill changes the selected picture format. It does not change the fixed optical offset or move the projector. Plan the physical coverage first.
Can I use any projector floor enclosure?
No. Confirm the LK830ST's dimensions, lens center, airflow, cable exit and the housing's intended impact protection. A product title saying “universal” is not a model-specific fit check.
Calculations checked October 17, 2026. Source: BenQ user manual, version 1.1, especially the LK830ST projection table on printed page 15 and mounting guidance on page 17. Values are approximate; verify the actual image and protected installation before permanent use.
