Category Archives: Synthesizers

Using the Sampler in Logic Pro X to Play and Slice Audio Samples

Let’s say you need an instrument that will play back recorded effects, slice drum loops into segments, automatically shift the pitches of sound so they’re always in key, and cut out bad “pops” other undesirable parts of a sound. Oh, and you also want it to play cool gating effects. What instrument would you use? The answer, of course, is a sampler. A sampler loads up recorded audio files and does some basic processing on them so that you can use them as an instrument.

I’ve never really been big into samplers. I started doing music after trackers were going out of style but before scripted sampling engines became big. As a result, I never really paid much attention to the “simple” sampler where you dropped in a sound file and had it play it back for you.

I want to walk you through using a sampler using Logic Pro X’s “Quick Sampler” because it’s, well, quick. The Quick Sampler was released as part of Logic’s 10.5 update and it’s fast and easy to incorporate samples into your music composition! However, even though the instructions here are specific to Logic, almost all samplers support these concepts.

Loading Samples

Drag and drop the sound directly from the Finder into the track header. Release the button and it’ll give you an option for what to do with the sample:

Drag and drop the sample from your filesystem into Logic’s tracks to create a Quick Sampler.
  • Original: Use the sound as-is. Great if you want to just play the sound back at different pitches using the piano roll.
  • Optimized: Analyze the sound and do a bunch of magic to set the sampler up around the type of sound you loaded in.

You can audition your sound with the tiny little play button under your sample, or you can use the piano roll and play the sample back (the default note is C3). For most sounds, the sound will play back as long as the note is held.

If you mouse over the note name here, the icon actually turns into a “Play” button that will audition your sample. It’s a little hidden.

Play Your Sample Like an Instrument

One of the great features of samplers is making the sample work across all kinds of different pitches and with all kinds of note lengths. You can change a quick snappy trumpet note into a long drone or pitch a really low-pitched sax into a high-pitched sax.

Load your sample and set it to “Classic” mode. The short version of how this works is that the sample plays as long as the note in the piano roll is held down (the longer answer is that the sample follows the amp envelope). Next, look for the loop points. If you hold the note down for longer than the sample’s length, then the sampler will loop across this range.

To make the loop sound good, you don’t want clicks or pops when you go from the end to the beginning. This means that you generally want the loop points to hit a point called a “zero crossing” (which is represented by the line). Fortunately, Quick Sampler makes it pretty easy to snap the loop points to zero crossings. Under “Snap”, choose “zero crossing”. Next, you want to set your loop so that the sound is as continuous as possible. To do that, you can zoom in on your sound’s waveform and imagine that you’re drawing a line from the end back to the start without an abrupt change in direction.

You want to set the loop points so that the waveform at the loop end and loop start cross from positive to negative (or negative to positive) through the zero crossing to avoid clicks or other sound artifacts.

The following video demonstrates some of the differences in the sound when you don’t snap to zero crossings, when you don’t match the waveform’s direction, and when you do line everything up.

Demonstrating how to use loop points on a sample to reduce clicking.

One Shot: Play The Entire Sound!

If you want your sample to always play back in its entirety, then use “One Shot”. This is best for drum sounds or sound effects where you always want the entire sound to play.

Slice Your Sample

A long-standing music production technique is harvesting drum loops from recordings, slicing them up, and then using them in different ways in your own music. This is not only fun, but it allows you to get some really interesting effects.

If you want to play each drum hit separately, you can use the “Slice” option in Logic. When you click it, it automatically cuts your tracks by transient and assigns it a note, and then you can use the note to play back each piece. Here’s a filtered hi-hat loop you can use to follow along with.

This sequence plays back each hit in the loop one at a time.

You can choose different ways for Quick Sampler to automatically cut your track up:

  • Transient: Cut your track using the sound as a guide – essentially, it tries to put each hit in its own region that can be played back with a note.
  • Beat divisions: Cut your sample into slices based on the tempo from your DAW.
  • Equal: Cut your sample into a specific number of slices. This is really useful if you know the BPM of the original sample and how frequent the hits are.
  • Manual: Manually slice your sample by hand.

In each of these cases, you can use the gear menu to copy the MIDI pattern and paste it as a region on your track. When you play it back, it should sound like the original.

Copy, then paste the MIDI Pattern to quickly play the sound in the region

With the region, you can move MIDI notes around to play the different hits in unique ways or even to gate parts of a sample! In the example video below, I use this technique to chop up a vocal.

Using “slice” and the piano roll to gate parts of a sample.

Recording Instantly From Logic

I’ve been talking a lot about how to load and manipulate samples that you already have, but what if you don’t have any suitable samples to work with? The Sampler makes it easy to create your own!

Using Quick Sampler’s “Recorder” mode, select an input source (which could be from your audio inputs, but it could also be from an instrument track in Logic). Press the red “record” circle, and then play the sound in the DAW. You’ll see the audio come through into the sampler. Press “Stop”, then select an appropriate mode for playback. You will likely need to edit the start and end points of your sample (hint: if it’s a loop, you might find Snap: Beat helpful).

Recording a baseline from Instrument 3 into the Sampler. You need to manually stop the sample and then trim it down at the end.

Why would you resample from your DAW when it’s already playing the sound? The cool thing about resampling is that you can chop up the result for some very interesting effects. Resample your voice and pitch it up or down for some robotic dystopia. Slice a loop up to gate and glitch it. Record some drums with huge reverb, but then gate the reverb out. There’s a lot of interesting things that you can do with samples even directly in the sample editor.

Let Quick Sampler Do The Work For You

When you load a sample into Quick Sampler, it asks if you want to use Original or Optimized mode. What’s the real difference? Optimized mode will attempt to auto-detect the nature of the sound and then tailor the sampler’s settings based on what it thinks works for the sound. It will:

  • Try detecting the pitch and put the sound on the corresponding note
  • Set the start and end so that it skips silence
  • Set loop points automatically
  • Slice the sample into drum hits if it’s a drum loop

Quick Sampler modulation and other sound-shaping devices

In addition to manipulating the sample itself, you can modify a number of pitch, filter, and amp envelope options. You can use these to creatively shape the sample to your needs! If you want a lush pad, for example, you could increase the attack on the filter envelope and increase the amp envelope release.

The sampler also contains a number of modulation options. Access the “Mod matrix” to see a list of possible controls, then map them so that you can control them from the piano roll or your MIDI controller.

If I’m drawing MIDI notes on the piano roll, then I like to map velocity to a target for some easy ways to introduce variety.

These features are part of almost every sampler!

Now you know more than enough to have fun with your samples. I like Logic’s Quick Sampler because it’s so easy to get started, but pretty much every DAW, and even hardware sampler, uses the same concepts in this post. From slicing to ADSR to zero crossings, you’ll be able to figure out any sampler!


Creating a Song in Squarp Instruments Hermod

I created a video to illustrate the use of the Squarp Instruments Hermod Modular Brain. This is a multi-sequence, polyphonic sequencer for Eurorack that interfaces with MIDI, USB, and CV made by the creators of the very popular Pyramid. Check it out!

I also have a more detailed video that goes into how Hermod’s step mode and zoom levels work.