"Instrumental "invert subtraction" fine-tuning"

I’m trying to use the invert feature in Audacity to subtract the instrumental track “song.mp3” from “song_and_effects.mp3” so only the sound effects remain. “attempt1.mp3” “attempt2.mp3” are my attempts, but they are not good enough as there’s still too much audio from the song and the quality gets severe damage. If anyone knows a better method or has some tips, please let me know. I tried all the vocal isolation and noise reduction tools already without any success.

https://drive.google.com/file/d/1_MmeaRzC3G23Mqd9FhcGZ0_qwb4QypAL/view

Do you only have MP3 versions? I’m unable to reduce the drumming by much because the MP3 encoding shifts the phase of high frequencies, making it impossible to achieve cancellation.

Here’s a short sample of what I’ve got after invert and mix:

And a short sample after invert and mix and then applying Noise Reduction:

I have a 320Kbps version of the original song (“song.mp3”), but “song_and_effects.mp3” is a mp3 re-encoded from a video that used WMA 9.2 192Kbps 41000HZ audio encoding, and I have no previous versions. Would that help? Here it is: https://drive.google.com/open?id=1Hav9jKrMOWGG9zj64emViFeVngEwUK92
I thought there might be a simple trick I missed and didn’t realize that the invert method is affected that much by different re-encodes of the same song. I already started with adding the sound effects separately so this topic doesn’t need further attention and can be closed. Thanks for the help and attempt, though.

That’s the amazing thing about compressed audio formats - they throw away 80% of the data without it “sounding” any different. The downside is that it IS different - it is not possible to throw away 80% of the data without losing something. This is why we highly recommend keeping an archive / backup copy of work in an uncompressed format (such as WAV or FLAC).