Mastering questions, answered
Straight answers to what engineers actually ask — getting loud without clipping, hitting the right loudness for streaming, fixing a muddy low end, and making a mix translate on every system.
Loudness & clipping
How do I make my mix louder without clipping?
Loudness comes from a smart limiter, not from cranking the gain. duet.to uses a proprietary, program-aware (program-dependent) limiter that adapts to your material — raising the track to competitive, streaming-ready loudness while preserving transients, so it stays punchy instead of squashed. The lossless master sits at about -0.1 dBFS sample peak, and the free AAC version is rendered with 1 dB of safety headroom so the lossy conversion never inter-sample clips.
What LUFS should I master to for Spotify, Apple Music and YouTube?
Those platforms normalise playback to around -14 LUFS, so that number gets quoted as a target. But -14 is a reference, not a finish line: master exactly there with loose dynamics and your track gets turned down and sounds flatter than the songs around it. The better approach is a slightly hotter master with controlled dynamics, so it still lands loud and full after normalisation. duet.to balances this for you automatically.
Does duet.to use true-peak limiting?
No — and that's deliberate. True-peak limiters clamp harder to chase inter-sample peaks, which dulls transients and, to our ears, makes a master sound worse. Plenty of commercial masters overshoot 0 dBTP by a dB or two without anyone hearing a problem, so duet.to masters to about -0.1 dBFS sample peak and lets inter-sample peaks fall where they naturally do. To keep the lossy conversion clean, the free AAC master is rendered with 1 dB of safety headroom — enough to prevent inter-sample clipping during AAC encoding, without ever touching the punch of your master.
Will mastering squash my dynamics and kill the punch?
It shouldn't — that's the whole point of how our limiter is built. duet.to's proprietary, program-aware limiter is designed to preserve transients rather than flatten them (it's also why we avoid true-peak limiting, which dulls them), so the master gets loud and stays alive and punchy. You can A/B the original against the master, with live loudness and spectrum meters, to hear exactly what changed.
Mix translation
Why doesn't my mix sound good in the car or on earbuds?
Usually it's tonal balance. A mix tuned to one room or one pair of headphones carries that room's quirks everywhere else — too much low-mid, a dull or harsh top end. Mastering references your balance against a wide target curve and evens it out, so the track holds up in the car, on earbuds, through a phone speaker and on a big system. duet.to does this automatically, with no reference track required.
How do I get my mix to translate everywhere?
Translation comes from a balanced frequency response and controlled dynamics — nothing sticking out, nothing hiding. duet.to shapes the EQ curve and evens the balance so the master reads the same across systems, giving you immediate, better mix translation everywhere. The live spectrum and loudness meters in the preview let you see that balance as it plays.
Does mastering help my mix on a phone speaker or in mono?
Yes — tightening the tonal balance and overall level helps a track hold up on small, mostly-mono sources like a phone speaker. Severe phase or mono cancellation is best fixed back in the mix, but a well-balanced master gives you the best shot at translating to those tiny speakers.
Low end & tonal balance
How do I fix a muddy low end?
Mud is usually build-up in the low-mids (roughly 150–400 Hz) on top of an uncontrolled sub. duet.to runs a proprietary de-mud algorithm that detects that build-up and significantly reduces it where it's found, then firms up the bottom so the low end is tight and powerful instead of woolly — while keeping the weight that makes the track feel big.
Why does my mix sound boxy or cluttered?
Boxiness is typically a bump in the low-mids plus a crowded midrange with no space. A master sculpts the tonal curve — clearing the boxy region, opening the mids and smoothing the highs — to bring clarity and definition to a dense mix, so individual elements read clearly.
Using duet.to
Do I need a reference track?
No. duet.to derives the target tonal/EQ curve and loudness automatically from your mix — there's nothing to pick or dial in. Upload your track and download a finished master.
How long does mastering take, and is it free?
Most masters finish in seconds, with live status updates. Stream-ready AAC (M4A) masters are free for a limited time; lossless WAV masters are 1 credit. There's no subscription, and credits never expire.
What can I upload, and what do I get back?
Upload WAV, AIFF, FLAC, M4A, MP3 or OGG — lossless sources give the best results. You get a free AAC (M4A) master, or a lossless WAV for 1 credit.
Hear it on your own track
Upload your mix and master it free — competitive loudness without clipping, an evened-out balance, and a live A/B preview with loudness and spectrum meters.