How to Test Your Phone's Latency Before Buying a Connected Drum Kit

A connected drum kit on a phone that is too slow is like running in flippers. You move forward, but not at the pace you want. The right reflex: measure the latency before you buy. And above all, know how to read the result. The number shown by a test app is not the whole story.

Why test latency before buying?

Because audio latency varies enormously from one phone to another, and no spec sheet mentions it. On Android especially, two models at the same price can give 15 ms or more than 100 ms.

Many people disappointed with connected drums simply had a phone that was too slow. A two-minute test would have saved them a product return. Better do it first.

What do latency test apps measure?

A test app only measures the phone's audio latency, nothing else. It does not take Bluetooth or the sensors into account.

The usual principle: the app plays a sound, picks it up with the microphone, then calculates the elapsed time. This is the device's "round-trip" latency. Free apps such as Superpowered Latency Test do this on Android.

On Android, the system also ranks devices by the latency it reports. There are roughly three tiers: under 15 ms, under 45 ms, over 45 ms. Some phones even exceed 225 ms.

How to calculate the real latency of your kit

This is where many people get it wrong. One user was surprised to see 5 ms on an iPhone, when Bluetooth alone already adds 12 ms. No mystery: the app only measures the phone.

To estimate the real delay between your stroke and the sound, add up:

1. The sensor: less than 1 ms, negligible.
2. The Bluetooth MIDI link: about 12 ms, whatever the device.
3. The phone: the figure given by the test app.
4. The audio output: almost zero when wired, huge over Bluetooth.

A concrete example: an iPhone showing 5 ms gives about 12 + 5 = 17 ms in total. An Android phone at 45 ms gives nearly 60 ms. You feel the difference right away.

What result should you aim for?

Under 15 ms on the phone side is excellent. Up to 45 ms is playable. Beyond that, the lag bothers most drummers.

As a guide:

• Under 15 ms: ideal, you will hardly feel anything.
• 15 to 30 ms: very good for practice.
• 30 to 45 ms: playable, but borderline. A result around 33 ms was judged "good, but only just".
• Over 45 ms: the delay becomes noticeable, especially at fast tempos.

These thresholds are only indicative. A beginner on a slow groove tolerates more than a seasoned drummer on a double kick.

Getting your test right: the right conditions

A badly run test gives a wrong number. Give yourself every chance:

1. Close all background apps, especially music streaming.
2. Disconnect Bluetooth headphones and earbuds. The test must use the speaker.
3. Turn off battery saver mode, which can throttle the processor.
4. Run the test several times and keep an average value.
5. Update your phone if possible.

Don't have the phone yet? Test it in a store or at a friend's who has the same model. It takes two minutes.

The video method: measuring real latency

To know the real delay between your stroke and the sound, film or record both at the same time. It is the only method that measures the whole chain.

The idea is simple: capture the sound of the stick on the pad, then the sound produced by the device. The gap between the two is your real latency.

Step by step

1. Place an external microphone (or a second phone) near the pad and the speaker.
2. Start the audio recording, or film a video if you prefer.
3. Play a few sharp, well-spaced strokes on the pad.
4. Open the recording in a free audio editor such as Audacity.
5. Find the two peaks for each stroke: the click of the stick, then the drum sound.
6. Measure the gap in milliseconds between them. Average it over several strokes.

Why an external microphone? Because the microphone of the device being tested adds its own delay. With a separate recorder, you measure what you actually hear.

What it looks like in practice

One user applied this method to two setups. On his computer, he measured about 15 to 20 ms. On his phone, around 40 ms. The test confirmed what he felt: the computer was much more pleasant to play on.

You can also film in slow motion. Each frame then represents a few milliseconds. By counting the frames between the impact and the sound, you get an estimate. It is less precise than audio, but it works.

Phone too slow? The alternatives

Don't panic. Several options exist:

• An iPhone, even an old one (from the SE onwards), generally offers low latency.
• A computer with a DAW (GarageBand, Reaper, Logic) often gives the best results.
• Another Android phone, chosen after a test this time. Our criteria: which smartphone to choose for a connected drum kit.

And remember the return period. Test in real conditions, then send it back if it does not work for you.

Conclusion: test, add, decide

Remember these three reflexes:

1. Test your phone with an audio latency app.
2. Add about 12 ms for Bluetooth, and forget wireless headphones (why?).
3. Decide: under 45 ms on the phone side, go for it. Above, change devices or use a computer.

Two minutes of testing can save you weeks of frustration.