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Large room · 15 × 20 × 7.5 ft

The 15 × 20 home theater

The classic finished-basement theater: long enough for two rows and rear surrounds, but with a lower ceiling that shapes the Atmos choice.

Recommended layout: 7.1.2 Atmos

Alternative: 7.1

7.1 plus two overhead speakers.

SCREEN15 ft wide20 ft longSEATLRCSLSRRLRRTMLTMRSUBSUB2

Main seat

12.4 ft

from the screen wall (62%)

Viewing distance

11 ft 5 in

eyes to screen

TV size

100"

102–114" is cinematic

Max projector screen

115"

lens 10 ft 10 in–16 ft 8 in back

First room mode

28 Hz

length axis

Volume

2250 cu ft

closest to IEC 268-13

Display

A 110 to 120 inch screen. With a 7.5 ft ceiling, a short-throw projector on a rear shelf avoids a low-hanging mount.

Seating

Two rows; keep the riser to 8 to 10 inches so the back row has headroom. First row at about 12 feet.

Speaker measurements

From the left wall, from the front wall, and floor to tweeter. Angles are from the main seat.

SpeakerLeft wallFront wallHeightAngle
Front Left2.2 ft1 ft3.3 ft25°
Front Right12.8 ft1 ft3.3 ft25°
Center7.5 ft1 ft2.8 ft
Surround Left1 ft13 ft4.8 ft95°
Surround Right14 ft13 ft4.8 ft95°
Rear Surround Left3.7 ft19 ft4.8 ft150°
Rear Surround Right11.3 ft19 ft4.8 ft150°
Top Middle Left6.2 ft11.8 ft7.5 ft63° / 71° up
Top Middle Right8.8 ft11.8 ft7.5 ft63° / 71° up
Subwoofer3.8 ft1 ft0.8 ftn/a
Subwoofer 211.3 ft1 ft0.8 ftn/a

What to expect in this room

  • A low ceiling puts in-ceiling speakers close to your head; two top-middle speakers beat four here.
  • Low-back seating for the front row keeps the surrounds clear.
  • Use the wire calculator: 14 AWG for the rear and height runs.
  • Two subwoofers at the front-wall quarter points (or opposing mid-walls) even out bass between seats. Run the subwoofer crawl to confirm.
  • width and height are close to a 2:1 ratio: every mode of the shorter dimension lands on a mode of the longer one.
  • 3 pair(s) of axial modes below 200 Hz coincide within 5%. Expect a strong peak at those frequencies.

Gear that fits this room

All categories

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Polk Audio Signature Elite ES20

Surrounds or a small-room stereo pair on a budget

Polk Audio Signature Elite ES20

Price tier 1 of 4
  • 2-way bookshelf, 6.5" woofer
  • 1" Terylene dome tweeter
  • 88 dB measured sensitivity
  • Bass to ~35 Hz in-room (ASR)

Audio Science Review measured genuinely deep bass and smooth, wide horizontal dispersion, and recommended it outright at its price. That wide dispersion and easy load make it a good surround or small-room front pair.

Polk Audio Reserve R700

Front left/right in medium to large rooms

Polk Audio Reserve R700

Price tier 3 of 4
  • 3-way tower, dual 8" woofers + 6.5" mid
  • 1" Pinnacle ring radiator tweeter
  • 88 dB sensitivity, 8 ohm nominal
  • 38 Hz (-3 dB), ported

A three-way tower that measured within roughly plus or minus 2 dB on-axis at Erin's Audio Corner with real bass extension to about 40 Hz, so it can play full range in a medium room. It shares drivers with Polk's flagship Legend series at a fraction of the price.

SVS SB-1000 Pro

Small rooms and music-focused systems

SVS SB-1000 Pro

Price tier 2 of 4
  • 12" driver, sealed
  • 325 W RMS / 820 W peak
  • 20 Hz to 270 Hz (+/-3 dB)
  • SVS app with 3-band PEQ

A compact 13-inch sealed cube that Audioholics found goes well beyond entry-level performance, with app control, parametric EQ, and clean 20 Hz extension. The natural pick for small rooms, music-first systems, or a pair on a budget.

Denon AVR-S670H

Basic 5.1 rooms and apartments

Denon AVR-S670H

Price tier 2 of 4
  • 5.2 channels, 75 W/ch
  • 3 of 6 HDMI inputs 8K/4K120
  • Audyssey MultEQ
  • Dual sub outs, no pre-outs

The least expensive Denon with current HDMI 2.1 gaming support and HEOS streaming. It is a sensible starting point for a straight 5.1 room, but it has no height channels and no pre-outs, so it cannot grow into Atmos.