VGM loop is on time but sounds weird

[SirDarwin]

Edit 3: Maybe I should take more time to read back the instructions before posting here but I now realize this kind of thing is mentioned in the tutorial, and the solution is to move the loop points to different samples until it sounds right. Now it sounds fine I think, but it might loop a wee little bit early which could affect the way it sounds. Let me know what you think and if this sounds good enough to be submitted. I will admit this version of the song sounds practically identical to the final, to the point where even people who have heard it many times would not be able to tell the difference. The main one I could spot was the flute-like sound in the background after the beginning part which cuts out between chords, unlike the final where it is constantly played. Isolate channel YM2612 #0 and compare it to the final to hear what I mean. Some of the tracks may not have any differences, but I still feel it's important to preserve these versions. Masato Nakamura and the rest of the sound team at Sega worked very hard on this soundtrack and I think it's important to appreciate everything that went into making it sound as good as possible, both big and small.

I hope I am in the right topic this time... On my quest to rip the Sonic 2 August 21 1992 soundtrack I believe I've ripped and edited Hidden Palace Zone correctly, however it doesn't really sound right when it loops at about the halfway point. I've attached both the vgm I ripped and the one from the final game so you can hear it.

Should I perhaps mark the end sample after 2 loops instead of 1? Although that might just make it so it sounds weird every other loop. Alternatively I could move the loop point to the end of the first loop so that it starts back at the second. OR still I could move the end and loop point so that it's a "cycle" after when it repeats itself (sorry I don't know the term, there are so many terms for 1/2/3/4 cycles in music like what is it a beat, a bar, a step, a half step!?)

And reading this back just confused me so maybe someone can put it in words better than I can...

Edit: I think I figured it out, for some reason the first note of the bass is missing when it loops. I have no idea what could've caused this since if I recall correctly, I don't think that happened at any point in the song..

Edit 2: The note is not missing it's just kinda weakened somehow. I can even hear the difference between the trimmed version and my original rip. Perhaps the way it was trimmed also altered the synth a bit part way into the note. But if I tried to fix it the beat might be off.

[Mao (RN22)]

did you use vgmlpfnd to find the correct loop point?

vgmlpfnd is the best tool that you can find accurate loop points than manual looping. but be careful, not all vgmlpfnd can find the accurate loop points for you.

instead, use "samples" reference from audacity, and then compare it to vgmlpfnd.

[ValleyBell]

IMO going with vgmlpfnd should not be the first thing.
Trying to trim and loop at least a bunch of tracks fully manually is what I recommend for learning.

Also, this is NOT the issue that SirDarwin has here.

1. regarding the missing note during the first loop: You set the "Start Sample" too late. The commands that set up the FM instrument are cut off, so the note doesn't sound. (or not properly)
   Move the "Start" point to an earlier time, e.g. by 200-400 samples. Then it should probably sound fine.
   In general, with FM chips you can expect a delay between "sound chip receives instrument data + key on command" and "you see an effect in the wave form". Tones fade in on FM chips and that takes some time.
2. regarding looping: If you set the loop/end points at the exact spot where you see the note playing in the wave form, the loop may not work.
   This is because the points are set during the time where the sound driver instructs the sound chip and just missing a single instruction can screw the loop up.
   You have to move the loop/end points by a few samples, but you should move them both by the same amount of time in order to keep the loop time intact.
   I usually set my loop points a tiny bit after the actual audible loop, because that is safer, but moving them to an earlier point may also work.

[Mao (RN22)]

You've got a point there.

If you're new to VGM ripping, I suggest to do manual looping if you don't know how to use vgmlpfnd.

Also, use VB's advice on how to trim or to set start samples properly.