These files are copyrighted by Sega and Capcom. You must own the original arcade hardware or legally purchased compilations. However, for preservationists, they are widely available via:
dl-1425.bin (24576 bytes) - NOT FOUND (qsound_hle) dl-1425.bin qsound-hle.zip
Note: Some variants include dl-1425.bin inside the same zip (especially in "universal BIOS packs" found on archive sites), but officially, they are separate components. These files are copyrighted by Sega and Capcom
Open your qsound-hle.zip file with a zip manager. Verify that the file inside is exactly named dl-1425.bin and is not buried inside a subfolder within the zip. Open your qsound-hle
In some cases, users have reported that the dl-1425.bin file may already exist in their ROM set under a different name. MAME displays the required file size in its error message (24576 bytes). Searching through all Qsound-related ZIP files on your system for a file of exactly this size can uncover the hidden binary. Once located, you can rename it to dl-1425.bin and compress it into a qsound_hle.zip archive.
The dl-1425.bin file is the for the Capcom QSound chip. Developed by QSound Labs and famously programmed by audio engineer Brian Schmidt, the QSound chip (hardware designation DL-1425 ) provided real-time 3D spatial audio fields over standard stereo speakers.