Error Guide
E-8305CDJ Error E-8305: FLAC Playback — Which CDJ Models Support It and How to Convert
You put a FLAC file on your USB, load it on the CDJ, and get E-8305 "UNSUPPORTED FILE FORMAT" (older players show "DATA FORMAT ERROR"). FLAC is lossless — the audio quality is identical to WAV — but Pioneer's FLAC support depends on the player model. The CDJ-3000, CDJ-3000X, CDJ-2000NXS2, CDJ-1500X and XDJ-1000MK2 play FLAC. The CDJ-2000NXS, CDJ-900NXS, XDJ-1000, XDJ-700 and every older model do not — and in a club with mixed players, one of those is enough to break your set.
First analysis free · no account needed
Technical cause
FLAC (Free Lossless Audio Codec) is a compressed lossless format. Unlike WAV and AIFF, it needs a dedicated decoder in the player firmware, and Pioneer only added one to newer models. According to the official manuals, FLAC plays on the CDJ-3000, CDJ-3000X and CDJ-2000NXS2 at 16 or 24 bit up to 96 kHz, and on the CDJ-1500X and XDJ-1000MK2 up to 48 kHz. FLAC plays from USB or SD card only — never from a burned disc. The CDJ-2000NXS, CDJ-900NXS, CDJ-2000, CDJ-900, CDJ-850, CDJ-350, CDJ-400, XDJ-1000 and XDJ-700 do not support FLAC at all, and the player throws E-8305 because it cannot identify the format as playable. A common source of confusion: rekordbox imports, analyses and previews FLAC regardless of which player you will use, so a FLAC track can look perfectly prepared in your library and still fail on an older CDJ. A 24-bit/96 kHz FLAC also fails on the 48 kHz-limited CDJ-1500X and XDJ-1000MK2 — there the sample rate, not the format, is the problem.
Manual fix (free tools)
Convert FLAC to WAV or AIFF if you play on older players or do not know which CDJs the venue has. This is a lossless decode — FLAC is lossless by definition, so the WAV output is bit-for-bit identical to the original uncompressed audio.
for f in *.flac; do ffmpeg -i "$f" -acodec pcm_s24le -ar 44100 "${f%.flac}.wav"; doneThis shell loop converts all FLAC files in the current directory to 24-bit PCM WAV at 44.1 kHz. The output filename keeps the original name and replaces the `.flac` extension with `.wav`. On Windows, use: `for %f in (*.flac) do ffmpeg -i "%f" -acodec pcm_s24le -ar 44100 "%~nf.wav"`
ffmpeg -i input.flac -acodec pcm_s24le -ar 44100 output.wav`-acodec pcm_s24le` outputs 24-bit signed PCM little-endian WAV — the most compatible CDJ format. If the source FLAC is 16-bit, use `pcm_s16le` to avoid unnecessary upsampling. Check the source bit depth with `ffprobe -v error -select_streams a:0 -show_entries stream=bits_per_raw_sample input.flac`.
fre:ac is a free GUI audio converter that handles FLAC to WAV batch conversion. Add your FLAC files, set the output format to "Microsoft Wave Audio" with 16 or 24-bit PCM, and click Convert. Download at freac.org.
In rekordbox 6.x, you can set the export format for USB devices under Preferences → CDJ/XDJ. Set "Convert to WAV when exporting" and choose 24-bit, 44.1 kHz. When you export tracks to USB, rekordbox will automatically convert FLAC files. Note: this only applies to the USB export, not to the source files in your library.
The Boothready way
Fix your entire library automatically
Boothready flags every FLAC file in your library, because you rarely know in advance which players the booth will have. With one click, the flagged files are converted to WAV so the same USB plays on every CDJ — old or new. If you only ever play on FLAC-capable players, you can simply keep your FLAC files.
Frequently asked questions
Which CDJs can play FLAC?
The CDJ-3000, CDJ-3000X and CDJ-2000NXS2 play FLAC at 16 or 24 bit up to 96 kHz. The CDJ-1500X and XDJ-1000MK2 play FLAC up to 48 kHz. All other Pioneer players — including the CDJ-2000NXS, CDJ-900NXS, XDJ-1000 and XDJ-700 — cannot play FLAC. Compare every model at /players.
Is converting FLAC to WAV a lossy operation?
No. FLAC is a lossless codec. Decoding a FLAC file to WAV produces a bit-for-bit identical copy of the original uncompressed audio. There is zero audio quality difference between a FLAC file and the WAV produced from it.
My FLAC plays fine in rekordbox — why does the CDJ reject it?
rekordbox desktop software supports FLAC playback and analysis for all CDJ target models, regardless of whether the physical hardware supports FLAC. This means a FLAC file can appear in your rekordbox library with cue points, waveforms, and BPM data — but still fail with E-8305 on a CDJ-2000NXS or XDJ-1000. The CDJ hardware decoder is separate from the rekordbox software decoder.
Should I store my library as FLAC or WAV going forward?
For DJ use, WAV or AIFF 24-bit at 44.1 kHz is the most practical choice — universally compatible with all CDJ models, no conversion needed at the gig. FLAC is better for archival storage (smaller file size, lossless) but adds a conversion step for CDJ compatibility. See all E-8305 causes at /cdj-error-e-8305.