AUD-01

Speaker Design

ANSI/AVIXA A102.01 · ANSI/AVIXA A104.01 · ANSI S12.2 · ISO 3382 · IEC 60268 · ITU-R BS.775-3; Dolby Atmos; DTS:X; Auro-3D

01 · Design task

Calculation

02 · Room

Room length

Room width

Ceiling height

Awaiting input4 fields left: Calculation · Room length · Room width · Ceiling height

Drawing

The drawing appears when the inputs are complete

01
Four related audio design tools in one: ceiling loudspeaker layout and coverage uniformity, EPR amplifier sizing against background noise, RT60 and intelligibility, and surround loudspeaker placement.
02
Tip. Coverage is specified at ear height, not at the ceiling. The throw that matters is ceiling height minus seated ear height, so a 3 m ceiling over seated listeners gives about 1.8 m of throw — barely half what the ceiling height alone suggests, and it roughly halves each coverage circle.
03
±3 dB — Uniform coverage (A102.01)
04
25 dB — Minimum dynamic range
05
6 dB — Loss per doubling of distance
06
0.6 – 0.8 s — Speech RT60 target

Loudspeaker system design

Four questions decide whether a room sounds right, and they are usually answered by four different people at four different times. This tool covers all of them against the AVIXA audio standards: how the loudspeakers cover the room, how much amplifier power they need, whether the room’s acoustics will let speech be understood, and where surround channels belong.

Coverage and amplifier power

Ceiling coverage is set by the throw to ear height and the loudspeaker’s coverage angle. Amplifier power follows from the target level at the listener, the distance and the loudspeaker’s sensitivity.

Use cases

A102.01 treats ±3 dB variation as uniform coverage
Throw is ceiling height minus seated ear height
Inverse square law — 6 dB lost per doubling of distance
Headroom covers programme peaks without clipping

Formula

W = 10^((target SPL + 20·log₁₀(d) − sensitivity + headroom) ÷ 10)

A102.01 · A104.01 · IEC 60268

Room acoustics and layout

Reverberation time governs intelligibility; background noise sets the dynamic range available. Surround placement follows the layout standard the content is authored for.

Use cases

Sabine RT60 from volume and total absorption
ANSI S12.2 NC/RC sets the noise floor target
ITU-R BS.775-3 for 5.1 and 7.1 base layers
Atmos, DTS:X and Auro-3D for height channels

Formula

RT60 = 0.161 × V ÷ (S × ᾱ)

ISO 3382 · ANSI S12.2 · ITU-R BS.775-3

Absorption coefficients are published averages for generic materials and vary widely with mounting, backing and air gap. Treat a calculated RT60 as a design indication, not a prediction, and verify by measurement once the room is built.