Interesting, I have my modem and router on different shelves, seeing your post I'll leave them that way, thanks.
A simple tweak for WiFi streaming only.
There’s about 12 inches of empty space – horizontally - between my modem and WiFi router – on the same shelf. Last night, I put a small cardboard box under the WiFi router – elevating it about 14 inches or so higher than the modem. The SQ became more full-bodied. I’m surprised that such a small change could yield a noticeable difference.
Apparently, the extra vertical separation mitigated the RFI intrusion into the WiFi signal - a little bit. If my cables were longer, I’d try to increase the separation even more. In addition, I placed a couple of ESD bags between the LPS’s and the WiFi router. I don’t think they’re doing much. I had them, so why not. YMMV
Note: This is not a wired vs wireless thread.