SoundScreen StoreProjection and screen sizing, worked out

Set-up guide

Surround speaker placement worked out: angles, distances and heights for 5.1 and 7.1

By the SoundScreen Store editorial team · November 12, 2026

Speaker placement guides are written in degrees: fronts at 22–30°, surrounds at 90–110°, rears at 135–150°. Rooms are measured in metres and feet. This guide does the conversion, so you can mark the positions on the floor with a tape measure before you drill or buy stands, and then tells you what to enter in the AV receiver.

What you need: a tape measure, some masking tape and the distance from your main seat to the front wall.

1. Mark the main seat

Everything is measured from the head of the person in the main seat. Sit down, and mark on the floor the point under your head. Then measure:

  • D: the distance from that point to the screen (or the front wall).
  • S: the distance from that point to each side wall.
  • B: the distance from that point to the back wall.

2. Front left and right: 22–30° each side

Dolby’s range for the front pair is a total separation of 44–60°, which is 22–30° either side of the center line; THX recommends 45° in total. With the speakers the same distance from you as the screen, the sideways offset from the center line is distance × sin(angle):

Seat to speaker at 22.5° at 30°
2.5 m (8.2 ft) 0.96 m from center 1.25 m from center
3.0 m (9.8 ft) 1.15 m 1.50 m
3.5 m (11.5 ft) 1.34 m 1.75 m

Each speaker is that far left or right of the screen’s center. The narrower angle keeps the sound close to the picture with a TV; the wider one suits a large projection screen. Angle both speakers toward the main seat.

3. Center: below or above the screen, aimed at your ears

The center goes on the center line, directly below the screen (or above it, or behind an acoustically transparent screen). If it sits well below ear height, tilt it up toward the seat so dialogue is aimed at your ears rather than your chest.

4. Side surrounds: 90–110°

Dolby and THX both give 90–110° for the surrounds of a 5.1 system and for the side surrounds of 7.1. At 90° the speaker is directly beside your head; at 110° it is slightly behind. How far behind depends on the side-wall distance S: S × tan(20°).

Your head to side wall (S) Speaker at 110° sits this far behind your head
1.0 m (3.3 ft) 0.36 m (14 in)
1.5 m (4.9 ft) 0.55 m (22 in)
2.0 m (6.6 ft) 0.73 m (29 in)

If the sofa is against the back wall, the 90° position is the only one possible; a 5.1 system works well there.

5. Rear surrounds (7.1): 135–150°

For the two extra speakers of a 7.1 system Dolby gives 135–150°. On the back wall, B metres behind your head, each rear speaker sits B × tan(180° − angle) to the side of the center line:

Your head to back wall (B) at 135° at 150°
1.0 m (3.3 ft) 1.00 m from center 0.58 m from center
1.5 m (4.9 ft) 1.50 m 0.87 m
2.0 m (6.6 ft) 2.00 m 1.15 m

If the back wall is less than about a metre behind you, 7.1 adds little over 5.1; spend on the front three speakers instead.

6. Heights

Dolby’s installation guidelines put all listener-level speakers at about the same height, typically 1.2 m (3.9 ft), the ear height of a seated listener. If the rear speakers cannot go at the same height as the fronts, they should be no higher than 1.25 times the front speakers’ height. Side surrounds placed much higher make effects sound as if they come from above rather than from beside you.

7. The subwoofer

Bass below about 80 Hz is hard to locate, so the subwoofer can go almost anywhere in the front half of the room. Where it goes changes how even the bass is at your seat, though. A practical method: put the subwoofer at your seat, play bass-heavy music, and crawl along the front wall and the front corners listening for the place where the bass sounds most even. Then put the subwoofer there.

8. What to enter in the receiver

  • Distances: sound travels about 343 m/s, so every 34 cm (13.5 in) of difference in distance is a delay of 1 millisecond. The receiver delays the closer speakers so the sound from every speaker arrives together. Enter each speaker’s distance to your head, or let the automatic set-up measure it.
  • Speaker size: set the speakers to Small unless they are large floorstanders, so the deep bass goes to the subwoofer.
  • Crossover: 80 Hz is the most common recommendation and the THX standard, according to SVS; SVS suggests 100–120 Hz for small speakers and 150–200 Hz for compact satellites.
  • Levels: run the automatic room correction from the main seat, or use the test tones and a sound level meter app to match levels.

Quick checklist

  1. Mark the seat; measure D, S and B.
  2. Fronts at 22–30° each side, angled to the seat; center on the center line.
  3. Side surrounds at 90–110°; rears (7.1) at 135–150°.
  4. Listener-level speakers at about 1.2 m; rears no higher than 1.25 × the fronts.
  5. Subwoofer at the place along the front wall where the bass is most even.
  6. Distances, Small, 80 Hz crossover, then room correction.

Sources