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Review of SQ4 Sequence Processor plugin by Dialog Audio


Dialog Audio have introduced SQ4, a software plugin designed for synchronizing and modulating hardware synthesiser parameters within a Digital Audio Workstation (DAW). It is available direct from Dialog Audio’s website typically priced at $49 in VST, AU and AAX formats (32/64 bit).


The SQ4 sequencer offers a number of connection possibilities:

The important point to bear in mind is that this plugin outputs midi or CV rather than audio and so you will need to route the connections appropriately. A basic setup involves adding a track for the SQ4 sequencer, a second track for the target device of external synthesiser or software instrument and creating a virtual midi connection between them. For CV signals additional audio tracks to receive the CV signal and send to a specific DC-coupled audio interface output are required.


This is an excellent sequencer, it can add functionality to hardware and software synthesisers alike. The main advantages I see for controlling software synths is that the SQ4 is fully customisable, you can control any parameter of a software synth or effect once you’ve set up the midi connections which offers lots of creative potential.

Whilst many modern synths contain arpeggiators, step sequencers etc there are a lot that don’t and SQ4 can enhance their functionality considerably. This is especially true for many hardware synths.

I had great fun using SQ4 to control various parameters of the monophonic synth Enkl (Klevgrand) and noise synth Noisetar (NuSofting). I also tried it with Cataract (Glitchmachines) and got great results. I really like how you can use the steps to create a bassline and then add subtle or more extreme movement to filters. Similarly for effects it’s a great way of adding a rhythmic element with a sequence and subtle or more extreme modulation. The resulting album is embedded at the top of this section, it’s a minimal tech house album arranged and recorded in Sensomusic Usine Hollyhock 3 as one-take live recordings.

An arrangement was created with SQ4 controlling Enkl and processed with Ultrachannel (Eventide); A drumloop processed with Ultrachannel (Eventide); SQ4 controlling Noisetar (Nusofting); Synthmaster 2 (KV331 Audio) processed with Convex (Glitchmachines) and Octavox (Eventide); Vocals processed with MangledVerb, Ultratap and Ultrachannel (all Eventide) with Type A (AudioThing) used on the master track. Settings and patterns were altered and four variations were recorded, a fifth version swapped the instance of Noisetar with Cataract (Glitchmachines).

The songs were subsequently mastered in MuLab 7 using EQ45 (Eventide), Type A (AudioThing), Elevate (Newfangled Audio) and Stage (Fiedler Audio).

In-Depth Review

There are detailed setup guides for several host applications on the Dialog Audio website. I use a different DAW from those listed, Sensomusic Usine Hollyhock 3, and I did have some trouble setting up SQ4 but with help from x.iso on the forums and some further experimentation it turns out that it’s extremely straightforward. It’s simply a case of configuring a midi out or a midi bus and assigning a multi midi filter. When you set the filter to control change, you set the filter number to the same cc channel as the sequences in SQ4 and the value out is then the converted midi messages you can use to control VST parameters. This is a ‘nuclear’ option, it covers VSTs that don’t have midi learn but as it’s so straightforward it’s an easy method to implement for any VST, regardless of whether they have midi learn or not.

The SQ4 interface is divided into 3 sections – output settings, sequence controller and the sequence editor.

Output settings allow you to choose midi cc, sysex or audio cv; you can select the external midi device or output to host to control a software synthesiser; select the midi channel and select the rate at which messages are sent to the device.

The control panel has two parts to it, the main controls which are all of the controls for each sequence and the output controls which determine the output options for the sequence.

There are three different types of sequences – curves, steps and slopes. The rate can be set as free, sync to host or ratio. The number of steps can be anything between 1 and 128. The drop down list has options of 1, 8, 16, 32 & 64 but you can manually enter any number. There are play options of forward, backwards, alternating and random. There are also offset, slew and swing controls.

The output settings determine the midi, sysex or CV parameters for each sequence.

The sequence editor is where you create your sequences. The steps are drawn by dragging up and down, the slopes can edited by click and drag on the points. Curves have a number of additional options including presets, copy/paste, load/save and combine steps.