Hello. I noticed that in small rooms there is no muffled reverb like in the original version from SonicEther. In addition, I hear a strong echo when I dig a two-block tunnel like I'm in a huge cave, is this a bug? The ported version is quite different from the original. "sorry for my bad english"

Weird, I don't have an echo effect at all on 1.18.1
I'm using the latest version of the mod at the moment (compatible with 1.18.1)
The rest of the effects seem to be working (weaker sound behind obstacles)

These are both probably because of a bug in 0.5.4 that has been fixed in commit f6c4fdc

The fix should be released soon

Let me know if this still occurs in 0.5.5 once it releases