Some recent high-end phones can run Brawl mods at about half speed on Android (very rough estimate). Setup is similar to Dolphin on Windows with the exception of the issues I posted above. I'm trying to make it easier for people to test this and hopefully tackle some of the emulator's issues.

Updated to latest Sammi Husky fix:

CSS Expansion, homerun, multiman Wifi fix:

Another update for CSS Expansion stuff; Same process as before, just replace the sora_menu_sel_char or miscData[13] in common3 with this and you will be able to use homerun contest and multiman brawl with CSS Expansion in Wiimmfii

Vanilla
PMEx

FYI, Dolphin originally needed IOS 36 for Gecko OS. Then there was a time it didn't. IOS 36 is now needed again. See https://bugs.dolphin-emu.org/issues/10663 for more information.

It works! Gameplay is somewhat slow but we're getting close. I'm using a Samsung Galaxy Note8 but keep in mind that a lot of older phones can't even run Dolphin Emulator. My setup is loaded through Minima Launcher and combined with a virtual SDHC card. Other launchers can also be used. I average ~37 FPS with Minima Launcher and Gecko OS.

If you get stuck on setup issues or driver bugs, https://forums.dolphin-emu.org/ is the best place to ask Dolphin-related questions. Setting up a Dolphin environment for Android is similar to PC. Here is some non-intuitive information if you do decide to go for this. This project is under active development so these things may change:

1. Android can't emulate the Wii Memory Management Unit (MMU) yet.

2. This isn't an issue unique to Android but it's worth mentioning: SDHC read times are very slow

3. This isn't an issue unique to Android but it's worth mentioning: Gecko OS DSI exception occurs when Emulated or Real Wii Remote is connected.

4. This isn't an issue unique to Android but it's worth mentioning: Project M Launcher is the only launcher that can load masterpiece demo games but it suffers from Project M Launcher can't use DSP HLE Emulation (average FPS ~30 with DSP LLE workaround)

Helpful information from JosJuice regarding applying a launcher workaround without changing global settings:

The file 00000000.ini should get applied to all DOLs and ELFs and also the GameCube IPL (if you're choosing to boot into the IPL itself rather than booting to a game when the Skip IPL setting is disabled). It isn't possible to be more specific than that.

Great!

[Post Merge: November 18, 2017, 08:06:11 PM]

https://gamebanana.com/gamefiles/5678
Here, try this then.
It's not the same build but the same exact issue happens.
At the time, I didn't know how to change the My Music menu (I do now) so the replaced songs in this build are Menu 2 (Melee) and Green Greens (Melee).

For the setup you linked, I was able to reproduce the faster, distorted audio when replacing W15.brstm with an arbitrary brstm. The included codes used a File Patch Code that wasn't File Patch Code 3.5.1b. Replacing the old code with File Patch Code 3.5.1b solved the problem for me. I couldn't test any CSE related codes as there was no string that matched "custom sound engine" or "cse" in the codes .txt file
Post Merge: November 18, 2017, 08:06:11 PMMenu 2 (Melee) and Green Greens (Melee) also sounded fine after replacing the file patch code

There's too many possibilities at this point so explaining what to do without having access to the files is impractical. I'd suggest trying the upload again later. Also, notifications aren't sent for post merges so you probably shouldn't reply until you have a link to your files.

If the problem isn't solved by 3.5.1b it would be more practical for me to have the files as previously mentioned so I can see what's going on in your setup.

I am indeed using BEx, let me try 3.5.1b.
BTW, this only happens on Dolphin, custom music is fine on Wii.

I suspect that's your problem. If it's not you can upload your files.

3.5.1 is fine unless you're using Brawlex. Brawlex needs 3.5.1b which is in the original Brawlex download.

I'm having the same problem. Dolphin just plays a messed up version of the replaced song instead of the one I put in. If it's over a CSE slot, it plays Mushroomy Kingdom's theme at a really high pitch instead.

Make sure you have the appropriate file patch code for your build.

 If you want, you can upload your SD contents (before inserting the problematic BRSTMs) to a file sharing service and post the link here. Include a .txt file with the codes included in your .gct and the problematic BRSTM files in the root of your SD card. I'll insert the BRSTM files myself.

Another way to screw up your imports:

10. Don't change the ForceFloat* Brawlbox import settings to False. Brawl doesn't support this. See Update warnings for (or remove) non-float Import Settings for more information.

Getting 6 and G mixed up. Huh... :S

That would definitely be a problem!

Just making sure, you need to rename your BRSTM files to the ones you want to replace. 608 and 609 won't be detected by Brawl. If you want to add songs instead you'll need the Custom Sound Engine v3.0 - Currently in Public Testing Phase and related codes.

Additionally, you're probably experiencing https://bugs.dolphin-emu.org/issues/10636
Dolphin incorrectly treated 2 GiB SD cards as SDHC. This should be fixed in Dolphin 5.0-5821 and later.

Answering yes to my second question indicates an issue that will be difficult to debug. If you want, you can upload your SD contents (before inserting the problematic BRSTMs) to a file sharing service and post the link here. Include a .txt file with the codes included in your .gct and the two BRSTM files in the root of your SD card. I'll insert the BRSTM files myself.