Supported Audio Formats
| Format | Extension(s) | Bit Depth | Sampling Frequency | Bit Rate | Encoding |
|---|---|---|---|---|---|
| MP3 | .mp3 | 16 bit | 32 kHz, 44.1 kHz, 48 kHz (MPEG-1) / 16 kHz, 22.05 kHz, 24 kHz (MPEG-2) | 32–320 kbps (MPEG-1), 16–160 kbps (MPEG-2) | MPEG-1 Audio Layer-3, MPEG-2 Audio Layer-3, CBR & VBR |
Some files may not play even if the format is listed as supported. The most common cause is encoding that technically matches the format but violates the exact spec — see compatibility issues below.
USB & SD Card Specifications
| Supported filesystems | FAT16, FAT32 |
|---|---|
| NTFS | Not supported |
| Max. folder depth | 8 levels |
| Max. folders per folder | 10,000 displayed |
| Max. files per folder | 10,000 displayed |
| USB hubs | Not supported |
| External optical drives | Not supported |
| SD card max. capacity | — |
| SD card standard | No SD card slot |
| CPRM (protected SD content) | Not supported |
Common Compatibility Issues
WAV files are not supported from USB
The CDJ-400 does not support WAV playback from USB at all. Only MP3 files can be played from USB. This is a fundamental hardware limitation — not a file encoding issue. WAV tracks that work fine on any newer CDJ will be completely invisible on the CDJ-400.
Full fix guide: CDJ E-8304/E-8305: 32-bit Float WAV Fix — Pioneer CDJAIFF files are not supported from USB
The CDJ-400 does not support AIFF playback from USB. Only MP3 files can be played from USB storage.
Full fix guide: CDJ E-8305: Compressed AIFF-C File Fix (ALAW, ADPCM)AAC files are not supported from USB
The CDJ-400 does not support AAC (.m4a, .aac, .mp4) playback from USB. Only MP3 files can be played from USB storage.
Full fix guide: CDJ E-8305: DRM-Protected AAC (iTunes Store) Cannot PlayHFS+ (Mac-formatted) USB not supported
The CDJ-400 only recognizes FAT16 and FAT32 formatted USB devices. HFS+ (Mac OS Extended), which is the default for Mac-formatted drives, will not be recognized.
Reformat your USB device as FAT32. On Mac: open Disk Utility → Erase → select MS-DOS (FAT) as the format. On Windows: right-click the drive → Format → FAT32.
USB: NTFS filesystem not recognized
USB devices formatted as NTFS are not supported. The CDJ-400 only reads FAT16 and FAT32.
Reformat your USB device as FAT32. On Windows: right-click the drive → Format → FAT32.
rekordbox library not supported
The CDJ-400 predates rekordbox and has no support for rekordbox-managed libraries. Tracks must be organized in standard folders directly on the USB device. Cue points, playlists, and BPM analysis from rekordbox are not available.
Organize your MP3 files in folders directly on the USB drive without using rekordbox. File and folder names are displayed directly.
Check your library
Scan for compatibility issues before your gig
Manually checking files works for single tracks. For a full library of hundreds or thousands of files, Boothready scans everything in one pass — WAV encoding, sample rates, FLAC compatibility on older models, and path lengths — and auto-fixes what it can before you export to USB.
About the CDJ-400
The CDJ-400 is Pioneer's entry-level player from 2008, designed for home DJs and small venues. Its USB support is strictly limited to MP3 files only — WAV, AIFF, and AAC are not supported from USB. It plays CDs (including MP3 CDs), but has no SD card slot and no rekordbox support. Understanding these strict format limits is essential before preparing USB sticks for any venue still running CDJ-400s.
- Released
- 2008
- Manufacturer
- Pioneer
- Product line
- CDJ entry-level series
- Position
- Home/entry-level player
- Disc support
- Yes — CD, CD-R/RW (MP3)
- rekordbox
- Not supported
- PRO DJ LINK
- No
Frequently asked questions
What formats does the CDJ-400 support from USB?
Only MP3. The CDJ-400 does not support WAV, AIFF, or AAC from USB. This is a fundamental hardware limitation. CDs can contain MP3 files, but uncompressed audio (WAV/AIFF) and other formats are not available from USB on this model.
Does the CDJ-400 support rekordbox?
No. The CDJ-400 predates rekordbox and has no support for rekordbox-managed libraries. Tracks must be placed in regular folders on a FAT16 or FAT32 formatted USB drive.
What file system does a CDJ-400 USB need?
FAT16 or FAT32 only. The CDJ-400 does not support HFS+ (Mac format) or NTFS. Maximum 10,000 folders and 10,000 files per folder. Always reformat USB drives on a Windows PC or use MS-DOS (FAT) format on a Mac.
Does the CDJ-400 have an SD card slot?
No. The CDJ-400 has no SD card slot. USB is the only media source besides disc.