Alex refined his search: "Dolby Atmos 7.1.4 channel check object-based audio download archive.org"
A 7.1.4 system is considered "proper Atmos" because it uses four overhead speakers rather than two, providing better front-to-back panning overhead. Home Theater Speaker Layout & Dolby Atmos Options dolby atmos 71 4 test download link
Before we provide the download link, you must understand what you are looking for. Many "Atmos test" videos on YouTube are misleading. YouTube compresses audio to Dolby Digital Plus (DD+) at best, which strips the true "object-based" metadata. To truly test , you need a lossless file (TrueHD) or a high-bitrate MKV/MP4 file. Alex refined his search: "Dolby Atmos 7
Turn off Dolby Virtualizer, Neural:X, or any "Surround Upmixer" on your AVR. You want or Atmos mode to hear the raw 7.1.4 objects. dolby atmos 71 4 test download link