How to Chop a Sample Into Pads on iPhone

Chopping a sample means slicing one longer recording — a vocal phrase, a melodic loop, a drum break — into pieces and spreading those pieces across separate pads. Once each slice has its own pad, you can finger-drum the sound in a new order, trigger individual hits, rearrange a groove on the fly, or build a whole kit from a single file in seconds. It’s one of the fastest, most musical things you can do on a phone, and GranSample makes the whole process a few taps.

This guide walks through it end to end: getting a sample onto a pad, opening the chopper, picking the right mode, mapping the slices, and playing them back.

Step 1: Get a sample onto a pad

Before you can chop anything, you need a sample loaded. You can record one straight from your device mic — up to 60 seconds — or import an existing audio file. GranSample reads WAV, AIFF, M4A, and MP3, so most loops and one-shots you already own will drop right in.

If you’re new to getting sound in, our companion guide on how to sample sounds on iPhone covers recording, importing, and tuning in detail. For chopping, almost any source works, but loops, breaks, and vocal takes give you the most fun to slice.

Step 2: Open the Sample Editor and tap CHOP

With your sample on a pad, open it in the Sample Editor — this is where you see the waveform and trim, tune, and shape the sound. Look for the CHOP button and tap it to open the chopper.

The chopper shows your waveform with slice markers laid over it, and lets you choose how those markers are placed. That choice — the chop mode — is the heart of the whole feature.

Step 3: Choose a chop mode

GranSample offers three ways to decide where the cuts fall. Each suits a different kind of source.

Equal

Equal mode divides the sample into evenly sized slices. Tell it how many pads to fill and it splits the file into that many equal pieces. This is ideal for sounds with a steady, even rhythm — a quantized loop, a roll, or any source where the timing is already metronomic. It’s also the quickest mode, since there’s nothing to detect or place by hand.

Transient

Transient mode listens to the sample and slices at each hit — the sharp onsets of drums, plucks, or consonants. Instead of cutting on a fixed grid, it cuts where the energy actually jumps, so each slice captures one real event. This is the mode built for drum breaks: it finds the kick, snare, and hat hits and lands each on its own pad, so you can replay or completely rearrange the groove.

Manual

Manual mode hands you full control. You drag markers along the waveform and place each cut exactly where you want it. Use this when the material is irregular — a spoken phrase you want split by word, a loop with an unusual feel, or any time the automatic modes don’t quite catch the moments you care about.

Step 4: Set the number of pads and confirm

Whichever mode you pick, decide how many pads the slices should fill. With 16 pads in a 4×4 grid, you can spread a sample anywhere from a couple of slices up to a full bank. Equal mode uses that number to size the cuts; transient mode maps the detected hits across the pads; manual mode reflects however many markers you’ve placed.

When the slices look right on the waveform, confirm. Each slice is assigned to its own pad, in order, and is immediately ready to play. If the result isn’t quite what you wanted, you can re-open the chopper and try a different mode or a different number of slices — nothing is destructive, so it’s worth experimenting until the split feels musical.

Step 5: Play and sequence

Now the fun part. Tap the pads to finger-drum your chops, triggering slices in any order to flip a loop inside out or reconstruct a break with a new feel. When you land on a pattern you like, lay it into the step sequencer — 16, 32, or 64 steps — to lock the groove and let it run.

Because every slice is just a normal pad, everything else in GranSample applies: per-pad tuning, envelopes, effects, and MIDI triggering all work on your chops too. You can see how the pads and sequencer fit together on the features overview.

Tip: make each slice granular too

Here’s where chopping gets really interesting. Each chopped slice lives on its own pad, and any pad can be switched from Linear to Granular playback. Flip a slice to Granular and suddenly you can stretch, freeze, re-pitch, and smear that one hit into a texture all its own — without touching its neighbours.

If you want to dig into what those granular controls actually do, read what is granular synthesis for a plain-language tour of grains, clouds, and the five knobs that shape them. Combining chopping with granular is how a single sample becomes an entire instrument.

Ready to start slicing? Get GranSample on the App Store and chop your first break tonight.