A curated directory of resources (plus some original content) for music producers and sound designers

Soundcraft Si Impact Digital Mixer

Everything you need to know to use this mixer - in one page.

Please note: everything on this page is definitely over-simplified and technically incorrect ...but that's intentional ;)

Video Introduction from Soundcraft

This is a quick list of this wonderful little desk's features; good for experienced sound engineers who want to understand quickly what this desk is capable of, but beginners can skip this video and move on.

Simplified Feature List

This is a Digital Mixing Desk, mainly designed for live use, and very popular with churches and small music venues.

It features:

  • 32 analogue inputs for microphones and instruments
  • full equalisation and dynamic processing on each channel
  • internal digital effects
  • the ability to connect to a digital stage box (purchased separately)
  • the ability to use an iPad for remote control
  • a usb connection to record directly to a computer
  • It can be expanded to accept up to 80 inputs!

  • Skip this if you have used a mixing desk before

    Beginner's guide to live mixing: connect something to the inputs

    Basically, the mixing desk is where all the sound sources (microphones and instruments) need to be connected, so that the sound engineer can adjust their respective volumes to produce a well‑balanced mix.

    Each microphone on stage needs to be connected to one of the mixer's MICROPHONE inputs; if you want to connect musical instruments like guitars and keyboards that have a 'jack' connector (the proper name is 1/4" TRS) you will need to use a D.I. box to come out with the connection and level that can be accepted by this mixer.

    Each channel has its own set of controls, so you can tweak and adjust each sound as they get all mixed together into a Master Channel (controlled by the L&R Fader on the right-hand side of the desk).

    The L&R Mix fader controls the level of the stereo mix that comes out from a couple of connections at the back of the mixer, and this is where you make the connection to the main speakers.

    Any mixer is, fundamentally, a box with quite a few inputs and at least one stereo output.

    In reality there will also be additional inputs and outputs to be used for adding artificial reverberation and other effects, and for monitoring (i.e. sending reference mixes to the performers on stage). But let's ignore all that right now.


    Looking at the back of the mixer, identify the inputs for your microphones and instruments.

    You could connect a microphone to one of these inputs to see if you can get any signs of activity on the mixer's display, but there are still many things that may need to be adjusted befoere this is going to work.

    Noise-Gates / Compression / De-Essing / Limiting

    Dynamic Processing Explained

    Those other confusing bits

    Learn them and forget them ;)

    Stage Monitors

    Using Aux Sends to create Monitor Mixes


    Recording to a computer

    Official Soundcraft Downloads page

    Visit Si Impact downloads and docs to find all the latest documentation, software, audio drivers, and firmware updates.