A picture of a test like a covid test on a desk, but it's got 10 frequency band tests and a Pre-amp test and oh god it's a graphic equaliser as a covid test. All the results show around midline so output is going to be flat.
https://files.bitbang.social/media_attachments/files/113/473/549/787/937/349/original/ec35092c85f7ef72.jpeg