The dl-1425.bin file is a digital dump of the internal from the QSound digital signal processor (DSP) chip, specifically the Capcom DL-1425 custom security and audio chip.
If you ever see an emulator claiming “QSound HLE” with no need for dl-1425.bin , be suspicious: you’ll likely get flat stereo or missing audio channels. dl-1425.bin %28qsound hle%29