Why Atmos?

Today I’m framing Atmos as a solution to three old problems:

Channel lock-in. Traditional formats (stereo, 5.1, 7.1) bind content to fixed speakers. Atmos decouples mixing from playback through objects and real-time rendering.
Scalability. The same master should travel from cinema to phone without bespoke downmixes. Atmos uses metadata and an adaptive renderer to target anything from 64-speaker dub stages to headphones. ([Dolby Professional][1])
Creative intent across devices. Object metadata lets me place and move sounds precisely; the renderer preserves those decisions on different layouts, including binaural. ([Dolby Professional Support][2])

By the end, students should be able to explain beds vs. objects, route a DAW to a renderer, export an ADM master, and evaluate delivery options for cinema, streaming, broadcast, games, automotive, and headphones.

From Mono to Immersive

Mono → one source, no spatial field
Stereo → phantom imaging between two speakers
Surround → 2D ring of speakers at ear height
Immersive → adds the vertical dimension (height)

The Gray Areas

Speaker vs. channel
Mono vs. stereo (fully correlated stereo is still mono)
Surround vs. immersive
Ambisonics vs. Atmos
Beds vs. objects (we’ll define precisely)

What Atmos Actually Is

Object-based authoring plus a real-time renderer
Typical music/post layout: 7.1.2 bed + up to 118 objects
Total inputs to the renderer at 48 kHz: 128
Renderer adapts to the room or device

Speaking Notes

This diagram comes directly from Apple’s Logic Pro 11.2 User Guide and shows how Logic routes Dolby Atmos audio differently depending on whether you’re using bed or object tracks.

Bed Tracks

Act like conventional surround channels—think of them as your fixed speaker mix (L, R, C, LFE, Ls, Rs, Ltm, Rtm).
Every bed track feeds into the same multichannel bus called the surround bed.
You can set that bed to 5.1, 7.1, or 7.1.2 in Project Settings → Audio → Surround Format.
The surround panner spreads signals across that multichannel bus before the Dolby Atmos plug-in.
Logic supports only one bed per project, with up to 7.1.2 width (meaning one overhead stereo pair).
Because of that limit, you can’t position sound at the front or rear of the ceiling—only at left/right top.

Object Tracks

Each object track bypasses the surround bus and routes directly to the Dolby Atmos plug-in.
Each object has a 3D Object Panner, which sends both audio (red arrows) and pan metadata (blue arrows).
Up to 118 objects are available. Each stereo track uses two objects.
Surround tracks can’t become objects—only mono or stereo sources.
The 3D Object Panner defines X, Y, Z coordinates and motion automation.
Logic keeps each object’s signal and metadata discrete all the way to the ADM BWF master file, the format delivered to Apple Music for Atmos releases.
Note: You cannot route object tracks directly to the LFE channel.

Summary

The bed represents traditional channel-based audio; objects are position-based elements in 3D space.
Logic merges both through the Dolby Atmos plug-in on the surround master channel strip, where pre- and post-fader effects can still be inserted.

This is a great point to pause and show in Logic how a bed track’s surround panner differs from an object’s 3D Object Panner.

Surround Panner vs. 3D Object Panner in Logic Pro

Speaking Notes

This side-by-side shows how Logic Pro 11’s interface distinguishes between channel-based and object-based spatial control.

Left – Surround Panner (Bed Track)

This is used on bed channels—traditional 5.1 / 7.1 / 7.1.2 buses.
You’re panning within a fixed loudspeaker ring (L, R, C, Ls, Rs, LFE, Ltm, Rtm).
The circular radar view represents azimuth—sounds move left-to-right or front-to-back within that 2-D plane.
Height is not available here; any “top” contribution comes from the 7.1.2 bed pair only.
Ideal for ambience, reverb returns, and music stems you want anchored to the speaker layout.

Right – 3D Object Panner (Object Track)

Used when a track is routed as a Dolby Atmos object.
Provides full 3-axis positioning: left/right (X), front/back (Z), and elevation (Y).
Includes object size and spread controls—metadata sent to the renderer in real time.
You can automate position or trajectory, enabling smooth motion through the 3-D field.
In the Dolby Atmos plug-in, these become individual “object inputs” (up to 118 total).

Pedagogical focus Demonstrate that the surround panner is channel-dependent, while the 3D object panner is spatially absolute. Ask students: “What creative choices might push you toward an object rather than a bed—clarity, motion, or localization?”

Atmos Delivery: Two Steps

Step	Format	Used By
1. Master	ADM BWF (beds + objects + metadata)	Apple Music, Tidal, Amazon Music
2. Playback Encode	DD+ JOC, TrueHD, AC-4 (from ADM)	Netflix, Disney+, Blu-ray, ATSC 3.0

Key point: Submit the ADM BWF master. Platforms encode to consumer formats internally.

Speaker Notes

When we release Atmos music, we don’t deliver a compressed bitstream — we deliver the source master: the ADM BWF.

Why ADM BWF?

It’s the official Dolby Atmos master format.
Contains every bed and object as discrete PCM plus spatial metadata.
Apple uses that data to generate their own Dolby Digital Plus JOC version optimized for Apple Music’s Spatial Audio.
This keeps future compatibility: if Apple updates headphone rendering or playback devices, your mix can be re-rendered from the same master.

What not to send

Never send the consumer bitstream (e.g., DD+ JOC, TrueHD). Those are playback encodes, not submission assets.
Think of DD+ JOC as the “end-user” product Apple generates from your ADM BWF.

Example Workflow

Export your Atmos mix as an ADM BWF (.wav) from Logic Pro, Pro Tools, or Nuendo.
Include the stereo reference master that matches time and content.
Deliver through your distributor (Apple Music for Artists, Tunecore, DistroKid, etc.) — they upload the ADM to Apple’s servers via iTunes Connect/Transporter.
Apple re-encodes internally into their own DD+ JOC format and generates binaural versions for Spatial Audio playback.

Other platforms

Tidal / Amazon Music HD: also request ADM BWF masters (they transcode to DD+ JOC for playback).
Blu-ray / Netflix: use encoded bitstreams (TrueHD or DD+ JOC), created after mastering, typically by a post-house.

Takeaway Always deliver the ADM BWF master as your definitive Atmos source — it’s what streaming services expect and what ensures consistent, future-proof rendering across devices.

Rendering, Not Downmixing

Speaker rendering adapts to any layout
It’s object-aware, not a blind fold-down
Same master serves cinema, home, mobile, and headphones

Binaural Rendering (Headphones)

Per-object binaural modes: Off, Near, Mid, Far
Used for Atmos on headphones (Apple Music, Tidal, etc.)
Optional personalized HRTF on Apple devices

Delivery Formats at a Glance

Streaming: Dolby Digital Plus JOC (object metadata inside DD+)
Disc: Dolby TrueHD with Atmos metadata
Broadcast: Dolby AC-4 (ATSC 3.0/NEXTGEN TV)
Cinema: SMPTE IAB (Immersive Audio Bitstream) in DCP/IMF
Apple TV 4K: Dolby MAT for Atmos to AVR/soundbar

Where You’ll Hear Atmos Today

Cinema, streaming originals, and discs
Major live sports and events in Atmos
Games on Xbox and PS5
Automotive systems
Music catalogs on Apple Music, Tidal, Amazon Music

DAW Support

Pro Tools Studio/Ultimate: integrated Dolby Atmos Renderer (2023.12+)
Nuendo: internal Atmos authoring, 9.1.6 support, external renderer optional
Logic Pro: built-in Atmos plugin and export workflow

Dolby Atmos Composer – Fiedler Audio

fiedler-audio.com/dolby-atmos-composer/
“Produce Dolby Atmos content on any DAW”
Key features:
- Objects & beds routing, export ADM BWF compatible.
- Works in DAWs that do not have native multichannel support.
- Version 1.6 introduces OBAM for full 128-channel master bus processing.

Introduce the tool: “Here’s a workflow alternative to the standard DAW + Dolby Atmos Renderer route. Fiedler Audio’s Dolby Atmos Composer lets you author, monitor, and export Atmos mixes from virtually any DAW.”
Why it matters: • Many DAWs (especially in music production) still have limited multichannel routing support. The Composer bridges that gap. ([Sound on Sound][2]) • For students working in studios without dedicated Atmos rooms or full rendering chains, this offers a more accessible entry point for immersive mixing.
Core workflow explanation: • Use the Beam plugin to send track audio + metadata (objects or bed assignments) into the Composer environment. ([Dolby Professional Support][1]) • In the Composer interface you select bed vs object roles, layout, monitoring format, and export to ADM BWF for delivery. ([Fiedler Audio][4])
Key distinctions: • Full version vs Essential: the “Essential” version offers basic Atmos workflows; full version adds advanced monitoring, 128 channels, OBAM, etc. ([Bedroom Producers Blog][5]) • The tool is approved by Dolby Labs, making exports compliant with standard Atmos delivery workflows. ([Fiedler Audio][6])
Classroom tie-in: • Ask students: “Given our workflow constraints (e.g., stereo DAW, headphones only), how might Composer change your approach to an immersive project?” • For a practical lab: Have students install the demo version of Composer, route a stereo track via Beam, mark it as object vs bed in Composer, export an ADM BWF, and compare playback in projected stereo vs binaural headphones.

Current Developments (2024–2025)

Dolby Atmos Renderer v5.0 released with updated licensing and docs
Broadcast/streaming: more live sports in Atmos
Open standard push: IAMF and Google/Samsung Eclipsa Audio for YouTube/TVs
Apple platform: ASAF/APAC for spatial and positional audio across iOS/tvOS/visionOS
Cinema exchange: increased use of SMPTE IAB labeling/workflows

A concise industry briefing for students:

• Dolby released Atmos Renderer v5.0 with updated distribution and support materials; creators can upgrade from Production/Mastering Suite. ([Dolby Professional Support][14]) • Live sports: Atmos is becoming table stakes—Super Bowl LIX via Comcast, weekly SNF on Peacock, plus Olympics/other events trend toward object-based delivery. ([The Verge][12]) • Open standards: the IAMF spec under the AOMedia umbrella underpins Samsung/Google’s new “Eclipsa Audio,” positioned as an Atmos alternative for YouTube and 2025 TVs/soundbars. This is meaningful for students shipping content to open platforms. ([The Verge][15]) • Apple’s WWDC 2025 quietly introduced ASAF (Apple Spatial Audio Format) and APAC (Apple Positional Audio Codec) for head-tracked immersive on Apple devices and visionOS; not an instant Atmos replacement, but important on Apple platforms. ([TechRadar][16]) • In cinema, Atmos playback supports SMPTE IAB; many workflows now label tracks “IAB” rather than “ATMOS.” Students should recognize both terms in DCP/IMF deliverables. ([registry-page.isdcf.com][10])

Services Snapshot

Apple Music, Tidal, Amazon Music: Atmos catalogs
Spotify: no native spatial/Atmos as of 2025