How to check your mix on a phone speaker

Why the phone speaker matters

Studio monitors show you everything. A phone speaker shows you what's left when most of the low end and nearly all of the stereo width are gone. That's a useful test, because it's close to how a lot of music is first heard: a clip on social media, a demo sent over a messaging app, a playlist on the kitchen counter.

The phone check answers one question: does the song still work? The vocal should be intelligible, the groove should still be there, and nothing important should vanish. You're not trying to make the mix sound full on a phone. You're making sure it doesn't fall apart.

What translates and what doesn't

Sub-bass: mostly gone

A phone speaker produces very little below the low-mid range. A kick's sub thump and an 808's fundamental largely disappear. What remains is the upper harmonics: the click of the kick, the growl or grit of the bass. If a bass part is almost pure fundamental, it can simply vanish.

The fix isn't to boost the lows. It's to make sure low instruments have some content higher up: a little saturation on the bass, a click or knock in the kick, or a doubled upper octave. Your ear fills in the missing fundamental from the harmonics.

Stereo width: mostly gone

Even with two speakers, the phone's image is only a few centimetres wide, and in portrait it's close to mono. Anything that relies on width to be heard, like a wide pad, a stereo-widened synth or a hard-panned double, will either collapse into the middle or lose level. That's why the phone check and the mono check go together.

Midrange: exaggerated

A small speaker puts most of its output in the mids, roughly where the voice, guitars, snare and synths live. Parts that sound balanced on monitors can turn harsh, honky or crowded. A little 2–4 kHz edge that felt exciting on big speakers can become fatiguing on a phone.

Dynamics: louder and flatter

Phones are often played loud, close to the speaker's limit, and some devices apply their own processing. Very quiet passages can get lost against room noise. You can't control the device, but you can check that quiet sections are still audible and that nothing depends on a big level jump to land.

A checklist for the phone check

• Vocal intelligibility. Can you understand the lyrics at a moderate level? If words get lost behind guitars or keys, look for masking in the mids.
• Kick and bass presence. Can you still hear the rhythm of the kick and the notes of the bass line, even without the lows?
• Balance of lead elements. Does the hook or the lead instrument still sit where you want it, or does something in the mids take over?
• Harshness. Are the cymbals, sibilance or bright synths fatiguing? Small speakers exaggerate that range.
• Missing parts. Does anything disappear entirely? That usually points to a width or phase problem, or a part with no content above the low end.
• Quiet sections. Are intros, breakdowns and fades still audible over real-world background noise?
• Level of effects. Reverbs and delays often sound louder on a phone, because the dry sound loses its low end and the effect doesn't. Check they don't wash the mix out.

Make the check a habit

The phone check is most useful early and often, not once at the end. A balance problem caught during the rough mix is a fader move. The same problem found after the mix is approved can mean reopening the session. Try checking at a few points: after the first balance, after the vocal is in, and before you print.

Also check in more than one position. Portrait, flat on a table, and landscape in your hands each sound different. Landscape is the closest a phone gets to stereo.

Doing it live with MixOutpost

The usual way to check on a phone is to bounce, send the file to the phone and play it. That works, but it's slow, so it tends to happen once at the end. It doesn't have to.

1. 01

   Put the plugin last on the master

   Insert MixOutpost (AU or VST3) on the last slot of your master output and press Start Sharing. Or use the MixOutpost Mac app to share everything the Mac plays. See the DAW pages for your host.

2. 02

   Pair and listen

   Scan the QR code once with the iPhone app, pick your Mac and tap Listen. The phone plays a lossless 48 kHz copy of the mix over your local network.

3. 03

   Pick the phone speaker

   Choose the speaker in the output picker. Tweak the mix on the Mac and hear the change on the phone while the session plays, with no bounce in between.

From the same screen you can switch Listen as to Mono or Side, use Dim (−20 dB) for a quick low-level check, or add a diagnostic EQ that mimics other small speakers. In landscape, the phone plays true left and right from its two speakers. The plugin never changes what your DAW outputs.

Logic Pro and Ableton Live are the hosts verified on real hardware so far.