MP3 vs WAV Delivery for Clients

Each Format Has a Job

WAV and AIFF are uncompressed PCM containers. They preserve the samples you printed and are the default for professional handoff, mastering, and archival. FLAC compresses losslessly—smaller files, same audio when decoded. MP3 and AAC are lossy: they discard data to shrink size and are ideal for messaging-app previews, not for remastering later.^[1]

Clients often say “send the track” without specifying. Your contract or delivery note should define preview vs final package so WhatsApp-compressed audio does not become the accidental master.

Technical Defaults That Keep You Safe

• Bit depth 24-bit for mix delivery; 16-bit only when a spec demands it after proper dither.
• Sample rate Match the session or the mastering engineer’s requested rate—do not upsample for mythic quality.
• Interleaved stereo Standard stereo WAV unless dual-mono is requested.
• Peak/loudness Leave headroom for mastering; label limited “client refs” clearly.
• Naming Include version, bit depth/rate, and date in the filename.

If a distributor asks for specific true-peak and loudness windows, meet those on the master package—not on every rough MP3. Spotify’s loudness normalization notes are a useful streaming context, but delivery specs come from the distributor you use.^[2]

Client Scenarios

Songwriter feedback loops: MP3 320 is fine if you keep the WAV master offline. Film/TV: follow the supervisor’s stem and broadcast specs—often 24-bit WAV at a stated sample rate with timecode conventions. Beat leases: WAV instrumentals plus MP3 previews for storefronts is common; tagged MP3s should not be the only file the artist owns after purchase—your license should state what they receive.

When clients insist on MP3 finals for “smaller Dropbox,” educate once, then deliver both: MP3 for convenience, WAV in the same folder. Charge time for stem exports; define sample rate and whether effects are printed.

Delivery Checklist

Quality Myths to Drop

MP3 320 is often transparent for casual listening, but cascading exports (MP3 → edit → MP3) accumulate damage. Upsampling a 44.1 MP3 to 96 kHz WAV does not restore lost data. “Mastered for iTunes” style guidance has evolved—follow current Apple/distributor docs when delivering specific platform masters rather than folklore.

Also drop the habit of emailing unlabeled files: `mix.mp3` fighting `mix2.wav` from different weeks is how wrong songs get released.

Client Communication Scripts

When a client asks for “just an MP3,” reply with a two-line clarification: you will send a 320 kbps preview for listening plus a 24-bit WAV for archive and mastering. Most clients accept immediately when you explain that chat apps recompress audio and that the WAV is the insurance policy for their release.

For film clients, mirror their language: sample rate, broadcast wave metadata, and whether they need continuous timecode reels. Do not invent specs—ask for the facility document. When they have none, propose a conservative default (24-bit WAV at the session rate) and get written approval.

Stem deliveries should include a README with start time alignment, included processing, and whether the lead vocal is dry or wet. A beautiful stem pack without a README creates mix rebuilds. Charge for stem time; it is skilled labor, not a free byproduct of mixing.

If a client loses files, your archive naming scheme is the product. Being able to re-send `Artist_Song_Master_v02_24b48k.wav` in minutes is worth more to your reputation than shaving five minutes off the original export process.

Field Notes

Beware messengers that transcode voice notes and audio attachments automatically. When possible, deliver finals via cloud links with original files intact. If you must use a messenger, state that the formal delivery link is the legal/archival copy.

For educational clients and students, include a one-page “how to download and verify” note. It reduces support load and prevents them from using a phone-recorded re-capture of your mix as a master.

Summary

Use lossless for anything that must survive processing or archival; use lossy for speed and feedback. Define packages in writing, name versions, and never let a chat-app compress become your master archive.