WAV vs MP3 vs AIFF: Which Format to Export
This is the most important decision, and the answer is not complicated: always export as WAV or AIFF for mastering. Never send an MP3 to mastering.
WAV and AIFF are uncompressed, lossless formats. They preserve every sample of audio data exactly as your DAW rendered it. There is no quality loss, no frequency content removed, no artifacts introduced. WAV is the industry standard and works on every platform and operating system. AIFF is functionally identical but slightly more common in Apple-centric workflows.
MP3 is a lossy format. It achieves smaller file sizes by permanently discarding audio data that its algorithm considers less audible. Even at 320 kbps (the highest standard MP3 bitrate), an MP3 file has lost frequency content above roughly 16 kHz and introduced subtle compression artifacts throughout the spectrum. Mastering cannot recover this lost data. If you master an MP3, you are mastering a degraded version of your mix, and the result will carry those artifacts into the final product.
Rule of thumb: Export WAV for mastering. Save MP3 for the final delivery format if a specific platform requires it. The mastering process itself should handle the conversion from lossless to lossy when needed.
FLAC is a lossless compressed format that some mastering services accept. It is bit-for-bit identical to WAV after decompression, just smaller in file size. If your mastering platform supports FLAC uploads, it is a perfectly acceptable alternative to WAV.
Bit Depth: 16-Bit vs 24-Bit vs 32-Bit Float
Bit depth determines the dynamic range and precision of your audio file. Higher bit depth means more resolution and less quantization noise in quiet passages.
- 16-bit provides 96 dB of dynamic range. This is the standard for final delivery (CDs, most streaming uploads). It is not ideal for mastering input because the limited resolution can introduce quantization noise during processing.
- 24-bit provides 144 dB of dynamic range. This is the standard for mastering input. It gives the mastering engine significantly more data to work with, resulting in cleaner processing, smoother fades, and lower noise floors. Export at 24-bit for mastering.
- 32-bit float provides virtually unlimited dynamic range. If your DAW supports it, 32-bit float is the best choice for mastering input. It is impossible to clip a 32-bit float file (values above 0 dBFS are preserved rather than truncated), which gives the mastering process maximum flexibility.
The practical difference between 24-bit and 32-bit float is small for most material, but 32-bit float provides a safety net: even if your mix accidentally peaks above 0 dBFS, the data is preserved and can be recovered during mastering. With 16-bit or 24-bit integer files, anything above 0 dBFS is hard-clipped and permanently distorted.
Sample Rate: 44.1 kHz, 48 kHz, or Higher?
The sample rate determines the highest frequency your audio file can represent. By the Nyquist theorem, a file can accurately capture frequencies up to half its sample rate. A 44.1 kHz file captures up to 22.05 kHz. A 48 kHz file captures up to 24 kHz. A 96 kHz file captures up to 48 kHz.
Human hearing tops out around 20 kHz (less as you age), so 44.1 kHz is theoretically sufficient for all audible content. However, higher sample rates provide benefits during processing:
- 44.1 kHz is the CD standard and the most common sample rate for music production. If your session is at 44.1 kHz, export at 44.1 kHz. Do not upsample.
- 48 kHz is the standard for video and broadcast audio. If your session is at 48 kHz (common when scoring to picture), export at 48 kHz.
- 96 kHz and above can reduce aliasing artifacts during heavy processing (especially nonlinear processing like saturation and limiting). If your session was recorded and mixed at a high sample rate, keep it for mastering. The mastering stage will handle the final conversion down to 44.1 kHz or 48 kHz for delivery.
Critical rule: Always export at your session's native sample rate. Never upsample (for example, converting a 44.1 kHz session to 96 kHz before mastering). Upsampling does not add real frequency content. It just creates a larger file with interpolated data that provides no benefit to the mastering process.
Headroom: How Much Space to Leave
Headroom is the difference between the loudest peak in your mix and 0 dBFS (the digital ceiling). Leaving headroom gives the mastering engineer room to apply EQ, compression, and limiting without immediately clipping the signal.
The standard recommendation is 3 to 6 dB of headroom, meaning your loudest peak should sit between -6 dBFS and -3 dBFS. Here is how to achieve that:
- Remove any limiter or maximizer from your master bus. This is the single most important step. If your mix is already slammed into a brick-wall limiter, the mastering process has no room to work. The result will be distorted and over-compressed.
- Check your peak level after bouncing. Open the exported file in your DAW or a free audio editor and look at the peak meter. If it is above -3 dBFS, lower the master fader by a few dB and re-export.
- Do not worry about loudness. Your mix will sound quieter without the limiter. That is expected and correct. The mastering stage handles loudness. Your job is to deliver a clean, dynamic mix with space at the top.
If you are exporting as 32-bit float, headroom is technically less critical because values above 0 dBFS are preserved. However, leaving 3 to 6 dB of headroom is still good practice because it prevents any unintentional distortion from plugins in your master bus chain that might not handle overs gracefully.
Dithering: When and How to Apply It
Dithering is the process of adding a tiny amount of shaped noise to an audio signal when reducing bit depth. It prevents quantization distortion, which manifests as a gritty, digital-sounding noise floor in quiet passages.
Here is when to apply dithering:
- Do NOT dither when exporting for mastering. If you are exporting at 24-bit or 32-bit float for mastering, do not apply dithering. Dithering should only be applied once, and it should be the very last step in the chain. The mastering process will handle dithering during the final export to 16-bit.
- DO dither when exporting the final master at 16-bit. If you are self-mastering and exporting the final deliverable at 16-bit 44.1 kHz, apply dithering (TPDF or noise-shaped) as the last plugin in your master bus chain.
Professional mastering platforms like LuvLang handle dithering automatically when you export to a lower bit depth. You do not need to think about it during export if you are using an online mastering service.
The Complete Export Checklist
Before you bounce your mix for mastering, run through this checklist:
- Format: WAV (or AIFF). Never MP3.
- Bit depth: 24-bit or 32-bit float. Never 16-bit for mastering input.
- Sample rate: Your session's native rate (44.1 kHz, 48 kHz, or whatever you recorded at). Never upsample.
- Headroom: Peaks between -6 dBFS and -3 dBFS.
- Master bus: Limiter and maximizer bypassed or removed.
- Dithering: Off. The mastering stage handles this.
- Stereo interleaved: Export as a single stereo file, not split mono files (unless your mastering service specifically requests stems).
- Tail: Leave a second or two of silence at the end so reverb and delay tails decay naturally rather than being cut off.
Follow this checklist every time and you will deliver a mastering-ready file that gives the processing chain the best possible starting point.
Export Settings After Mastering
Once your track is mastered, the final export format depends on where the music is going:
- Streaming (Spotify, Apple Music, YouTube): 16-bit, 44.1 kHz WAV with dithering applied. Most distributors (DistroKid, TuneCore, CD Baby) accept this format and handle the lossy encoding for each platform.
- CD: 16-bit, 44.1 kHz WAV (Red Book standard). Dithering applied.
- High-resolution streaming (Tidal, Amazon Music HD): 24-bit, 44.1 kHz or higher FLAC or WAV. No dithering needed since you are staying at 24-bit.
- SoundCloud or personal distribution: WAV or high-quality MP3 (320 kbps) depending on the platform's upload limits.
A good mastering platform gives you multiple export options so you can download the right format for each destination from a single mastering session. LuvLang supports WAV, FLAC, MP3, and AAC exports at multiple bit depths and sample rates, with automatic dithering applied where appropriate.