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1. Hello World - Making Sound

Bell Synth Voice Bell Synth Voice

What Is Bell?

Bell

Bell is a visual programming environment available freely on the web. Including a robust patching environment for building complex DSP, Bell also hosts a hardware patcher for mapping and flashing Daisy-based hardware with your program!

Goal

daisy bud

In this tutorial, we will be learning how to make sound with Bell, as well as how to create a Bell account and save our patch. This is the Bell equivalent of the "Hello World!" programming tutorial!

You can see the completed patch below:

Example Patcher

Prerequisites

This tutorial is suited for anyone interested in learning Bell!

To get started, all you will need the following:

  • Computer with an internet connection
  • Web browser

Tutorial

daisy bud

Video Tutorial

Let's make our first Bell project!

To get started, open up bell.audio in a web browser.

Step 1: Create A saw~ Object

Open the Object Library in the left menu, navigate to the saw~ object, and drag it into the patcher.

Getting Help With Objects

To learn more about how the object works, you can read the reference documentation by right clicking the object and clicking "Open reference."

If you need an example patch of an object, open the help patch. Right click the object, and click "Open help patch." (1)

  1. right_click

The saw~ object is a sawtooth waveform generator with pitch control. This will become the main sound source for this tutorial, and the tutorials to come.

The Object Library is a list where you can find all objects in Bell. For the rest of the tutorial, we will be creating objects using the double-click command. The library will still be available for browsing and reference.

Step 2: Create A scope~ Object

In the patcher, double-click to create a new object, type scope~, and press Enter.

This is how we will be making objects moving forward. You can also create objects by pressing the N key.

The scope~ object is an oscilloscope utility tailored for visualizing audio signals. Time is on the x-axis and amplitude on the y-axis.

Step 3: Patch saw~ To scope~

Click the saw~ outlet and drag the new patch cable to the scope~ inlet. Then, turn on the audio engine by unmuting the patcher in the bottom right corner.

In order to view our waveform on the scope, we need to patch the saw~ object's outlet to the scope~ object's inlet.

By default, the audio engine in Bell is not running. To toggle the audio engine state, click the speaker icon in the bottom right. You can also adjust the master volume of your Bell patch by hovering over the icon and dragging the volume slider.

Step 4: Create A dac~ Object

Warning: Loud Audio

This step will introduce sound. Set your audio output to safe listening levels to prevent hearing damage.

Double-click in the patcher and create a dac~ object. Patch the saw~ outlet to the dac~ inlets to hear sound!

The dac~ object let's us listen to our patch using our system's currently selected audio output device. DAC stands for "digital to analog converter" and converts the 1's and 0's in your patch into analog audio that you can hear.

I don't hear any audio.

You should hear a steady sawtooth wave at 440Hz. If you don't hear anything, here are some things to try:

  • Is your audio engine turned on? The speaker icon in the bottom right should look like this .
  • Double-check that there are patch cables connected between the saw~ outlet and the dac~ inlet.
  • Can you hear other sound coming from your browser? You can use the audio example below to test:

If you are unable to hear this audio file from our tutorial, you need to check your audio settings on your computer/external audio interface.

Your patch should match the Bell patcher below:

Step 5: Create An Account

create account

If you want to save your Bell patches without exporting them, you can make an account in the top right corner of the patcher! Click the login button, then click Create Account.

Step 6: Save Your Patch

save patch

Once your account is created, you can save and recall Bell patches connected to your account at any time! Navigate to the File menu button and click Save, or press Ctrl+S.

If you are saving for the first time, you can name your patch here. If you want to save your patch without overwriting an existing save, click File and then Save as..., or press Ctrl+Shift+S.

Let's save our current patch as subtractive_synth.bell!

Digital To Analog Converter

First computer to sing - Daisy Bell

Next Steps

daisy bud

We are making sound with Bell! Turning knobs and tweaking faders is fun, but how can we get our synth to shape our sound?

Head to the next tutorial to learn how to build a filter and vca section!

Tutorial 2: Filters & VCAs