To find an uncompressed 7.1.4 Dolby Atmos demo Blu-ray disc for a home theater, you have a few options. Many audio equipment manufacturers and retailers offer specialized Dolby Atmos demo discs that showcase the capabilities of this immersive audio format. These discs typically feature high-quality, uncompressed audio tracks that allow you to experience the full impact of 7.1.4 Dolby Atmos in your home setup. You can search online for Dolby Atmos demo Blu-ray or check with local specialty audio stores to see if they have any uncompressed 7.1.4 Dolby Atmos demo discs available. Additionally, some Dolby-certified home theater systems may come bundled with a demo disc, so you could inquire about that when purchasing or setting up your equipment.