SQ and SoundGrid: virtual soundcheck without changing inserts

Prepare recording, playback and the return to live inputs

If a playback track uses a port reserved for an insert return, it can replace the signal expected from the rack or create an unintended loop. Map the channel input and the insert send/return separately before changing any assignments. Test one identifiable track at a controlled listening level.

Keep separate paths for tracks and inserts

Allen & Heath's USB-B virtual soundcheck guide explains how to assign DAW outputs and feed SQ channels from USB. Sending every track to the computer's stereo master does not recreate the multitrack patch.

Proposed rehearsal: use a track's USB output to feed its SQ channel and leave the insert send/return on the intended Waves ports. Draw both paths: track → USB-B → channel input; insert send → card → rack → card → insert return. This separates the two functions, but the actual setup still needs testing.

Choose an identifiable track and channel, with listening limited to the test destination. Keep the rack's original assignments and compare meters and sound when switching from the physical source to USB. If the track reaches the channel but not Waves, trace the insert send; if Waves returns another signal, check the return. Do not reassign every port to troubleshoot one channel.

Before testing more tracks, list the inserts on inputs, groups and mixes. Track number, SQ channel and Waves port can differ. Do not use an occupied port simply because its number matches the channel.

An official alternative uses playback through SoundGrid Studio and the I/O Port, illustrated with Tracks Live on Mac. The article requires matching sample rates and Control Network Bridge set to Off for that configuration. This example does not define your insert assignments: prepare a separate map of recording, playback and processing before using it.

Set the clock source according to which device supplies it. For a card identified as M-SQ-WAVES3, AP11564 Issue 1, p.2, the note distinguishes SQ Internal/card Digital from SQ I/O Port/card Ethernet when the mixer follows another system. The presence of a server does not determine that choice. Check clocking and networking for the actual card.

Two input patch libraries, with every channel checked

In Connections and Patching, Input Channel Patch Libraries, open Library from I/O > Inputs > Input Channel. A library stores the entire input patch, not just the source currently displayed. A one-to-one USB preset can also change inputs you intended to keep live.

In the show copy, prepare the stage patch and save it with a clear name, such as Live Band A. Then change only the inputs that will receive tracks and save Playback Band A. Check a talkback microphone or another source that must remain live separately: it needs to retain its source in both libraries.

Build the library around the recording you will use. If guitar comes from SLink 4, was recorded on track 12 and feeds SQ channel 9, the playback patch must connect those assignments.

Recall Playback and check each selected source. Also check channels excluded from playback, inserts and destinations. Retain the EQ or dynamics changes you are trying; record any Trim change so you can decide whether it belongs in the show or only compensates for the file.

Do not recall a complete scene just to change the source without reviewing its filters and safes. If other settings also need to be recalled, follow the SQ scenes and inserts guide and check which connections are recalled.

Tie Lines and Direct Outs: identify what the recording contains

The SQ V1.6.0 guide, §6.7, p.27 routes Tie Lines from socket to socket without channel processing or level control. A Direct Out takes its signal from a processing channel. In the input block diagram, p.126, Post Preamp appears after Width, Trim/Pol and DEEP Preamp, before the HPF. The description on p.46 reduces this to preamp gain, so the two explanations differ. Check the complete path and test active blocks on the installed version before treating a recording as unaffected by them.

For a recording intended to replace the channel source, the proposed route is I/O > Tie Lines: choose the Local or SLink source socket and the intended USB destination socket. Record the socket and analog gain for each track. An existing recording alone cannot establish that gain or reproduce the microphone's current position.

The SQ guide, §8.1, p.46 shows Direct Out Source and follow-fader/mute options as global settings, alongside an individual level for each Direct Out. If recording from Direct Outs, document all those settings. Before changing the global ones, list other feeds that depend on them, such as personal monitoring.

Proposed rehearsal: repeat the same passage in a copy and compare a Tie Line recording with one from the chosen Direct Out. Identify the path in each file. Listen after stopping the recording and note which changes were captured. If a recording already contains EQ, gating or plugins, processing it again can change the result; do not try to correct that solely by raising Trim.

The file lets you work with a recorded signal. When returning to the stage, check the real source and its interaction with the PA and monitors. Playback does not demonstrate how open microphones will behave in the current setup.

The DAW plays, but the channel does not receive the expected signal

SQ-Drive and USB-B, the official May 2026 document, and the V1.6.0 guide, p.110, specify USB-B 32×32 at 48 or 96 kHz. SQ-Drive and USB-B share patching; while SQ-Drive plays, it feeds the USB inputs. Stop returns the source to USB-B; Pause does not. Simultaneous recording was introduced in V1.6.0; to choose destinations and check backup coverage, follow simultaneous SQ recording.

If the DAW meters move but the intended channel does not, check the audio device, that track's output and the USB socket assigned on SQ. Then check whether SQ-Drive remains in playback or pause. If another source appears, stop that playback during rehearsal and repeat one known track.

Connecting to a Computer distinguishes computer outputs, which reach SQ USB inputs, from SQ USB outputs, which reach computer inputs. On Windows, ASIO with a compatible application provides multitrack access; WDM uses USB 1/2 for system audio. Mac uses Core Audio. Record the actual operating system and driver before diagnosing the cable.

When comparing levels, retain the channel settings in the copy and measure at the same point. First check which processing was recorded, then the DAW output level and path. If compensation is needed, identify it in the playback session; do not apply an unexplained difference to every console Trim.

Check the sample rate and configuration before opening the test session. If the sample rate changes, record which applications need restarting according to their documentation. Identify the computer, card, DAW and SuperRack before choosing drivers.

Finish the test with the stage inputs live again

Agree with FOH and stage crew on the pause and who authorizes the return. During rehearsal, stop playback, recall Live and request a phrase or real signal from each intended source. Also check talkback, PA, monitors and recording. Hearing a track after the change does not confirm that the microphone is live again.

Record the libraries used, channels that stay live and mix changes you decided to retain. If the band's patch changes, review both libraries: a correctly named copy can still contain another day's assignments.

Complete the SQ virtual soundcheck worksheet. It includes recording, playback, inserts, levels and return-to-stage fields, with results left blank. Avoid loading a one-to-one preset over a different patch, feeding an insert return with a playback track, confusing Pause with Stop, or changing a global Direct Out setting without checking the other feeds it affects.

Related: SQ and effects returns, FOH/monitor consoles and other soundcheck workflows (Spanish guide) and show continuity. Prepare the paths and rehearsal with the operator of the event audio system.