if want the recording to sound identical, you'll need to use a lossless codec...
If you want it to be *mathematically* identical, yes. But *sounding* identical is much less strict. See "MP3". :-)
Yes, lossy compression can be abused, and I'm sure you've heard the results of such abuse. And for intermediate work, you do want to keep it lossless so that a series of small imperfections don't pile up. (generational loss) But for final distribution, most people aren't going to notice at all, the difference between a 64kb/s lossy compressed version and a 1411.2kb/s uncompressed version of the exact same thing. (stereo, 16-bit, 44.1kHz)
Whenever I record desktop audio, the audio in the recording always sounds different and lower quality than what I'd usually hear. It sounds a bit more like I'm listening to the audio from a distance, or through a car speaker.
I'm running OBS on Windows 11.
I suspect the real problem is that Windows is primarily designed for business people, not media. Business people don't have a clue about anything technical, so of course they're not going to even notice, let alone fix, an acoustically terrible conference room or lobby or whatever. Likewise for Microsoft's other market: consumers at home.
In both cases, the user *will* be in a poor environment, and they want their Zoom call or whatever to "just work". So Windows has some audio processing under the hood to make that happen. And it's hidden so that the kids, or a nosy business person who thinks he's doing something productive, doesn't mess with it. You need to find that, figure out what MS decided to call it, and turn it off. Likewise for any other "consumer candy" there might be by default.
What does most of the work in a "conference clean-up", is a Noise Suppressor. OBS has one too, as a filter, but it's not on by default. Those are designed for spoken voice only. Anything else - music, sound effects, etc. - is considered as noise to be removed. You probably don't want that. :-)
