@PabloMK7, I'm finally successful in BCSAR Hacking! The pause was because I didn't loop the BCWAV / WAV. So, I started again and created a looping WAV file this way:
1. Open the song in Audacity
2. Convert to Mono if not done already
3. Make sure that the file is not longer than the original one
4. Re-sample audio to 32 KHz
5. Find the loop point (samples)
6. Export as Microsoft Signed 16-bit WAV
7. Download Wavosaur (a free program that supports looping WAV files)
8. Open the edited 16-Bit WAV in Wavosaur
9. Go to Tools > Loop > Create Loop Points
10. Now go to Tools > Loop > Properties and enter the Loop Start Sample
11. Go to File > Save as and saved the file as "0x888EA0.wav" (16-Bit WAV)
12. Now open the file with ctr_wavconverter32.exe" (in CTR_SDK_11-4-0)
13. Output "0x888EA0.dpsadpcm.bcwav"
14. Now did the injecting part with HxD and inserted bytes (00 Hex Values) to take up the rest of the unused bytes (the bytes that are part of the old BCWAV)
15. Saved the BCSAR as "ctr_dash.bcsar"
16. Replaced with the old BCSAR in ROMFS
17. Re-built the ROMFS (using ROMFS Builder, of course)
18. Copied to \sdmc:\hans
19. Ran using HANS and tested it
And finally, success!
My mistake that I forgot to loop the BCWAV!