The SQ can use any output or Tie Line to route audio to the USB bus. For input channels, Tie Lines can be used to send an unprocessed, post preamp signal that isn't affected by any fader or mute controls, or the direct output. The direct output settings can be changed in Routing > Direct Out Settings > Global Direct Out Settings to:

• Post Preamp
• Post HPF
• Post Gate
• Post Insert return
• Post PEQ
• Post Comp
• Post Delay

A per channel direct output trim is also available, along with other global setting which determine whether the direct out follows fader and mute setting for the channel and assigned DCA’s and mute groups.

By default, Tie Lines are used for input channel sends to USB and SQ-Drive is selected as the USB audio source, this can be changed to USB B in the Setup > Audio > USB page.

The SQ can receive a signal from the USB bus and assign it to an input channel or mix external input. USB 1&2 are assigned to stereo input 47/48 and labelled USB by default.

The default recording format is WAV 96kHz 24bit Interleaved. The sample rate can be switched to 48kHz in the Setup > Audio > USB page (V1.5+).

SQ-Drive – Record and Playback Stereo (2-Track) and Multitrack (16 or 32 channel*) using a USB drive.

Not all USB devices will guarantee flawless performance. Please refer to the following guidelines for sourcing a suitable USB device.

• USB flash 'key', 'stick', or 'thumb drive' - most keys on the market are not fast enough for multitrack recording. 
• SSD drives - generally suitable for recording but can be prone to performance degradation over time, also some forms of wear levelling and 'garbage collection' algorithms can cause write speeds to become reduced during recording. 
• HDD drives - magnetic drives are generally suitable for recording but can suffer from physical disturbances such as vibration due to low frequency exposure, which can throw the head off-track and cause a delay while the actuator repositions it, eventually impacting on the input/output performance.
• SCSI drives - hard drives using the SCSI command protocol ATAPI are not supported. Only drives that communicate over USB Attached SCSI are supported. This is not obvious when looking at drives and you will need to consult the manufacturer’s data

The smallest USB drive size that should be used with SQ-Drive is 2GB.

The maximum USB drive size (FAT32 file system limit) is 2TB.

The maximum file size on FAT32 is 4GB. This will allow a maximum recording time per track of roughly 4 hours, and would need 64GB drive capacity for maximum recording time of 16 channels at 96kHz.

We recommend formatting the drive before each use, this clears the drive, sets up the folder structure and formats into FAT32. Once the USB is formatted for SQ-Drive, we recommend using the formatted drive for SQ recording only, and not used with other applications.

A list of user tested USB drives can be found here. The most recent entries can be found at the bottom of the list.

Below is a list of non-supported routing combinations.

• Stereo Playback + Stereo Record, not supported simultaneously.
• Stereo Playback + Multitrack Playback, not supported simultaneously.
• Stereo Playback + Multitrack Record, not supported simultaneously.
• Stereo Record + Multitrack Playback, not supported simultaneously.
• Stereo Record + Multitrack Record, not supported simultaneously.
• Multitrack Record + Multitrack Playback, not supported simultaneously.
• SQ-Drive Playback/Recording (stereo or multitrack) + Playback/Recording from USB B (streaming from DAW) not supported simultaneously.

*With the USB sample rate set to 96kHz mode, 16 channels are available for recording and playback with SQ-Drive. With 48kHz mode selected (V1.5+), this changes the channel count to 32 channels. 

USB B – 32 x 32 audio interface

The SQ conforms to USB 2.0 standards, so it is recommended to use a high-speed USB A to USB B cable, preferably one which also features a ferrite bead to prevent potential interference from the systems environment.

Select the USB B port when recording into a DAW, this will allow 32x32 audio streaming.

The SQ is Core Audio compliant and does not require drivers for Mac OS, an ASIO/WDM driver is available for Windows systems on our website: www.allen-heath.com

Windows operating systems supported:

• Windows 7 (64 Bit)
• Windows 8
• Windows 10

Not all USB 3.0 ports are fully backwards compatible with USB 2.0 –USB 3.0 ports using xHCI host controller drivers should be avoided and many are known not to support the isochronous transfer method used for streaming audio.

Inputs and outputs can be routed to and sourced from a USB channel, which allows for insert send and return via USB streaming. Simply go to a channel insert section and select a USB channel as your send and return channels.

For troubleshooting issues with the USB B interface, please click here