In reply to a recent comment

tolli8 September 2016 at 22:39

I did a lot of digging around about sysex too. It turns out that sysex works over https AND localhost. Very sparse documentation about web Midi sysex tho. I'm struggling to do anything useful with the API docs. Need some examples

Have a look at my A3000 example. This uses sysex messages to control the sampler.

When it comes to which sysex to use. It depends on which device you are trying to control. Check the manual for your device for the correct messages to send.

SSL and Github

Problem solved, install to Github and make sure you add https to the address if you need to access MIDI Sysex.

Example Midi Applications

Web MIDI Sysex and Browser Permissions

Tried to upload some Web MIDI examples to my pwdm.dk, only to have a problem sending Sysex messages. And as all the functionality in the A3000 Remote is Sysex, this was very important to fix.

So after a half a day searching I found the solution. Sysex access is only allowed if the hosting website has a SSL certificate.
So rather than pay the fee to upgrade my account, I decided to try uploading the site to Github.
Will post as soon as I get it working.

Web Audio API Nodes

Nodes = Modules

In our description of a synthesizer we talked about the different modules we can use to create and sculpt sound. All these modules can be created using Web Audio Nodes. There are four basic nodes:

• Source
• Transformation
• Analyser
• Destination

The source is a buffer that holds the audio data we wish to work with. In the following diagram you can see that we have three types of sources:

• Microphone
• Sample
• Oscillator

The transform node could, for example be a gain node so we can boost the amplitude of the input signal. Using an analyzer node we could display the input signal on screen. And of course the output node that connects to your computer/soundcard output.

For more details on how this is implemented I highly recommend the Web Audio School, contains many good code examples.

Web Synthesizer: Basics

Plan for Web Synth

As part of a school project International module, I was required to work with Open Source Software.

To this end I decided to build a Web Synthesizer based on the new Web Audio Api. At a basic level the API allows you to patch audio and signal nodes to each other, to create sounds. Much like traditional Modular Synthesizers.

Modular Synthesizer

 As you can see this contains modules or nodes that can be connected to produce sound. This type of synthesizer is very versatile in its ability to sculpt different tones. Although it can be a bit overwhelming once you start patching (connecting the nodes together) a beast like this.

Patched Modular System

To ease the complexity of these systems, we can assemble a few nodes and make permanent connections between the nodes. Giving the user a simpler interface to contend with.

Basic Synthesizer Signal Flow

Here we see three sound sources, two Omni Oscillators and a Noise Oscillator. These produce the basic tones we need to create sound. 

The sources signals are mixed together and sent on to the Envelope Generator. This controls the amplitude of the input signal, so we can achieve sounds that vary in amplitude over time.

The next stage is a filter that works by cutting or boosting certain frequency in the input. The filters intensity can also be controlled over time by the Envelope connected to the filter.

And finally the Effects/Output node, that can apply changes to the signal in various ways. For example to create and echo effect, where the input sound is repeated with distinct gaps between each repetition before fading in amplitude.

So thats a basic synthesizer layout. In the coming post I will show how I created a synthesizer similar to this using the Web Audio API.

Coming Soon

Julian Treasure: Sound design for a better life

Julian Treasure: The 4 ways sound affects us

An interesting talk about how sound can affect us more than we might think. Also some useful information about how sound design can affect the user experience.

The Secret Rules of Modern Living: Algorithms

Another fantastic documentary from the BBC about algorithms.  As ever fulfilling there charter to educate and entertain. Marcus du Sautoy explains and demonstrates some of the most common algorithms in an interesting and easy to understand format. With many a good example of the importance of algorithms in our every day life.

Marcus du Sautoy