My first concern upon reading the draft is that it's essentially an idea that has already been done on this site before. There are a lot of SCP articles tagged as 'recording', with SCP-1038 and SCP-1127 being particularly close in similarities. I would recommend giving those tagged articles a quick scan, because I feel I've read this before and, whilst I do actually enjoy these anomalous recording scips, there's only a need for so many.
Regardless of that primary concern, I'll go through the nitty-gritty.
soundproof container in Site-76.
Is there a reason it has to be soundproof? There's no indication it can play on its own.
Before and after testing SCP-XXXX-1 is to be cleaned thoroughly with a microfibre cloth in order to preserve its condition. A standard DVD player and television set are provided for testing.
This is about testing procedure, not Special Containment Procedures. Additionally, talking about cleaning is generally seen to be redundant, unless it's unusual cleaning, which it is not in this case.
For the description, I think you need to start it as such -
'SCP-XXXX is composed of two parts - SCP-XXXX-1 is [blah] and SCP-XXXX-2 is [bleh].'
digital versatile disc (DVD).
No need to be that technical in this case, 'DVD' is fine.
All the further description is fine in terms of clinical tone and grammar but, again, is very similar to SCP articles we already have that are about recordings. There's nothing wrong with that exactly, but there's nothing making your work stick out against an already well-developed list of DVDs/CDs/auxiliary cables that cause anomalous effects. Also, although a backstory isn't essential, one has to wonder how The Foundation discovered these two objects, and what they could do together. Remember, you as the author know everything, but The Foundation has to find out naturally, so how did they find out about this? Again, you don't have to include a backstory, but you have to let the reader believe that this is a thing that could be discovered naturally by The Foundation.
The Life and Times of D-█████
I don't know why they'd bother to hide the anonymous number of a D-Class who was also now deceased. It's not like it's their proper name.
Dr. ████████ committed suicide immediately after the beginning of the test.
The driven to suicide trope is not particularly intriguing for the reader. If that's the only outcome you can think of for an unusual string of letters, then maybe it shouldn't be included - or you could think of a better, more interesting outcome. I won't deny that The Foundation would try with names of things that don't exist, but why not a Safe scip, for example? Or a Lovecraftian horror? Something that's already fiction?
Foundation agents have been dispatched to locate ██████ █████████.
This test hides so much information that it's not intriguing to the reader - instead, it's just a little pointless, because it gives no air of mystery to the documentary.
Once it became clear that the recording would not end, Dr. █████ attempted to eject SCP-XXXX-1 via remote control. After this failed, he applied physical force to the DVD player until it broke and SCP-XXXX-1 was retrieved. The DVD player has since been replaced.
I guess this is a good way to show how they learned that the DVD cannot be ejected, but, beyond that, it's another boring outcome that doesn't entice the reader.
I suggest if you want to stay with this idea, you give the recording-based scips a read, to see how they use intrigue to develop their idea - they normally start with mundane ideas, like you did, but then slowly develop it into weirder and more intriguing ideas, rather than ending on a flat note like a documentary about pi, though I do understand why you included that test in general.
