# Is This File Really Immersive? How to Check Any Audio or Video File > A file called "Atmos" or "spatial" is not proof of anything. Learn the five signals that show a file is truly immersive, then inspect, play in 7.1.4 and quality-check your own file free in the browser. Web page: https://spatial9.ai/blog/is-this-file-really-immersive Author: Spatial9 Team Published: 2026-11-03. Updated: 2026-11-03. ## Key takeaways - A file name, a folder label or a player badge does not prove a file is immersive. Only what the file declares inside it does. - A WAV file shows its speaker layout through a channel mask; 0x3F, for example, means a 5.1 layout: front left, front right, centre, LFE, back left and back right. - An ADM BWF master carries chna and axml chunks defined in ITU-R BS.2088. Without both, the file holds tracks but no ADM scene description. - A two-channel file can still sound spatial on headphones, but the space is baked into the stereo signal: there are no channels or metadata for a player to render. - Structure is not sound quality. A correctly labelled file can still be a poor mix, so always finish with a listening check. - The free Spatial9 inspector plays ADM, Dolby and surround files in a live 7.1.4 room, compares Eclipsa Audio (IAMF) in stereo and binaural, and runs an optional loudness, true-peak and clipping check on your device. Short answer: a file is immersive only if it carries more than stereo in a form a player can render: extra channels with a declared speaker layout, object metadata such as ADM, ambisonic channels with matching metadata, or an immersive codec such as IAMF. You can check all of this without listening, by reading the file structure. The free inspector below does that in your browser, without uploading anything, and it plays ADM, Dolby and surround files in a live 7.1.4 room so you can see every object move. Eclipsa Audio (IAMF) files open in a stereo versus binaural A/B player, because they adapt to the listener's device. The same tool has its own page: Try your current files. People send us files every week labelled "Atmos master", "spatial mix" or "3D version". Some are exactly that. Many are ordinary stereo files with a new name. This guide shows you how to tell the difference in under a minute, and what each signal really means. ## Why the label is not enough A file name is typed by a person. A badge in a music app describes what the service delivered to you, not the file you downloaded. Even a "binaural" export is usually two channels of normal stereo audio. None of these prove that a file holds immersive data a player could use. What does prove it is the file structure: the container, the codec, the number of channels, the declared speaker positions and any spatial metadata. Those are written by the software that created the file and can be read back reliably. ## Inspect your own file Drop any audio or video file into the inspector. It reads WAV, BWF and ADM, RF64, AIFF, CAF, FLAC, MP3, AAC, Opus, Ogg, MP4, MOV, MKV, WebM, IAMF, AC-3, E-AC-3, DTS, WMA, DSD and more. Everything runs locally in your browser. ## Play it in 7.1.4 and run a quality check After the report, select Open the 7.1.4 player. The file is decoded on your device and rendered into a virtual 7.1.4 room: seven ear-level speakers, one LFE and four height speakers. - ADM BWF masters. Beds sit on their speakers, and each object appears as a coloured dot that follows its position and timing from the ADM blocks. You can mute or solo any bed group or object. - IAMF (Eclipsa Audio). Channel-based and ambisonic audio elements are decoded and placed in the room. PCM, Opus, AAC and FLAC substreams are supported where your browser offers the matching decoder. - Everything else. Stereo, 5.1, 7.1 and other multichannel files play on their own speakers, so you can hear whether the channel order is right. Listen on headphones, where the room is rendered binaurally, or send 12 discrete channels to a multichannel audio interface if your system offers one. The optional quality check scans every channel for clipping, true peak, silence and DC offset. It also measures integrated loudness on the 7.1.4 render using the ITU-R BS.1770 method, then lets you download a plain-text report to share with a client or engineer. Good to know: the player is a preview renderer for checking placement and movement, not a reference monitor. Dolby Atmos objects inside E-AC-3, TrueHD or AC-4 cannot be decoded in a browser, and IAMF object elements play without their movement data. The loudness figure is a guide, not a certified meter. ## The five signals that a file is immersive ### 1. More than two channels Mono has one channel and stereo has two. A 5.1 file has six, 7.1 has eight and 7.1.4 has twelve. A channel count above two is the first requirement for a channel-based immersive file, though not the only one. ### 2. A declared speaker layout Channels alone do not say where each one should play. In WAV files, that job belongs to the channel mask in the WAVE_FORMAT_EXTENSIBLE header, defined by Microsoft. Each bit stands for a speaker position, starting with front left. | Channel mask | Layout | Speakers | | 0x3 | Stereo | Front left, front right | | 0x3F | 5.1 | Front L/R, centre, LFE, back L/R | | 0x60F | 5.1 (side) | Front L/R, centre, LFE, side L/R | | 0x63F | 7.1 | Front L/R, centre, LFE, back L/R, side L/R | A six-channel file with no mask is a warning sign. The tracks may be in the right order, or they may not, and every tool will guess differently. ### 3. ADM metadata (for object-based masters) Object-based mixes such as Dolby Atmos music masters are usually delivered as ADM BWF files. According to ITU-R BS.2088, the chna chunk links each audio track to an ID in the scene description, and the axml chunk carries that description as XML, using the Audio Definition Model from ITU-R BS.2076. The inspector reports both chunks and counts the audio objects it finds. If a file has many channels but no chna or axml, it is multichannel audio without an ADM scene. If it has one chunk but not the other, the metadata is incomplete. Our guide to ADM BWF files explains the format in depth. ### 4. An immersive codec In MP4 and MOV files, the audio codec matters. AAC and Opus can carry several channels. AC-4, MPEG-H and IAMF were designed for immersive audio. IAMF is the open format behind Eclipsa Audio, specified by the Alliance for Open Media; see our IAMF technical deep dive. E-AC-3 deserves a special note. It can carry Dolby Atmos as an extension, but that cannot be confirmed from the container alone, so the inspector says so rather than guessing. ### 5. Spatial video and ambisonic metadata 360 degree videos need extra signals. Google's spatial media specification defines an sv3d box for spherical video and an SA3D box for ambisonic audio. YouTube's help centre requires first order ambisonics in AmbiX format (ACN channel order, SN3D normalisation), as a 4-channel track, or 6 channels with head-locked stereo. Four channels without the SA3D box will play as plain multichannel audio, not as sound that turns with the viewer. ## What the inspector cannot tell you A file can pass every structural check and still be a poor mix. A five-channel upmix may be nothing more than stereo copied into extra speakers. A perfect IAMF file can still be played back as stereo by a device that does not support it. The inspector checks what a file declares. It does not judge how it sounds, and it does not predict what a specific platform will do with it. So treat the result as step one. Step two is a listening check on the system your audience will actually use. Our article on headphone and speaker spatial audio explains why the same file can sound very different on each. ## Common results and what to do next - Stereo, 2 channels. Not immersive, even if it sounds wide. If you want a true immersive version, start from stems or the original session. See binaural vs spatial audio. - Multichannel with no speaker mask. Ask whoever made the file for the intended layout before using it. - Multichannel WAV with a mask, no ADM. A channel-based master. Good for surround delivery; it carries no object metadata. - ADM BWF with chna and axml. An object-based master that tools such as Spatial9 can read and convert to Eclipsa Audio. - MP4 with IAMF. An Eclipsa Audio file. Playback still depends on the device; see Eclipsa Audio for YouTube creators. ## Frequently asked questions ### Can a stereo file be immersive? It can sound spatial on headphones if it was rendered binaurally, but it is not an immersive file. The space is fixed into two channels, so no player can adapt it to other speakers or to head movement. ### Does the inspector upload my file? No. It reads the file inside your browser tab. Nothing is sent to Spatial9 or anyone else. ### Why does the report arrive before the audio is decoded? The structure of a WAV or MP4 file sits in a few small sections. The inspector reads those sections first, which is why large masters can be checked in seconds. The audio itself is only decoded when you open the 7.1.4 player or run the quality check. ### Is the 7.1.4 player free? Yes. The player and the quality check are free and run on your own device. Rare formats load a decoder the first time you need one, about 30 MB, and nothing about your file leaves the browser. ## Sources - ITU-R BS.2088: Long-form file format for the international exchange of audio programme materials with metadata (BW64), International Telecommunication Union. - ITU-R BS.2076: Audio Definition Model, International Telecommunication Union. - ITU-R BS.1770: Algorithms to measure audio programme loudness and true-peak audio level, International Telecommunication Union. - ITU-R BS.2051: Advanced sound system for programme production, International Telecommunication Union. - WAVEFORMATEXTENSIBLE structure, Microsoft Learn. - EBU ADM guidelines: BW64 and ADM, European Broadcasting Union. - Immersive Audio Model and Formats (IAMF) specification, Alliance for Open Media. - Spherical Video V2 RFC and Spatial Audio RFC, Google spatial media project. - Use spatial audio in 360-degree and VR videos, YouTube Help. ## Check, then convert Once you know what your file really is, you know what it can become. Spatial9 turns stereo tracks and ADM masters into Eclipsa Audio for YouTube, TVs and soundbars. Dolby and Dolby Atmos are trademarks of Dolby Laboratories. Spatial9 is not affiliated with or endorsed by Dolby Laboratories.