Feature Proposal: Expand Matrix Mixer Support for USB Audio Interface Channels Product: Line 6 Helix Stadium XL Subject: Expose USB Audio Interface Returns (3/4–7/8) as Matrix Mixer Sources

[rikkimadan]

Firstly, congratulations to the Line 6 team on the Helix Stadium XL.

The Matrix Mixer, Showcase integration, independent output buses, and USB audio interface have made the Stadium one of the most innovative live-performance processors currently available.

This proposal is intended to unlock one workflow that I believe would make the Stadium XL the definitive all-in-one live performance hub for professional touring musicians.

⸻

Current workflow

Many modern touring musicians now use a laptop running Cubase, Ableton Live, Logic, MainStage or Reaper as the central show controller.

The DAW simultaneously provides:
    •    Backing tracks
    •    Click tracks
    •    Spoken cues
    •    MIDI Program Changes
    •    Snapshot automation
    •    Tempo automation

The Helix Stadium XL already receives MIDI perfectly over USB.

The missing piece is flexible routing of USB audio returns.

⸻

Current USB Routing

Currently:

USB 1/2

✔ Appears directly in Matrix Mixer

✔ Independent level

✔ Independent routing

✔ No DSP path required

USB 3/4

Requires DSP Path

USB 5/6

Requires DSP Path

USB 7/8

Requires DSP Path

This means additional DSP paths are consumed purely for routing audio rather than processing it.

⸻

Real-world example

Professional live show

Inputs

Helix
    •    Guitar
    •    Bass
    •    Vocal

Cubase

USB 1/2

Stereo Backing Tracks

USB 3

Click

USB 4

Voice Cue

USB MIDI

Program Changes

Snapshot Changes

Tempo Changes

 

Desired Matrix

XLR (FOH)
    •    Guitar
    •    Bass
    •    Vocal
    •    Backing Tracks

(No Click)

(No Cue)

⸻

Phones / IEM
    •    Guitar
    •    Bass
    •    Vocal
    •    Backing Tracks
    •    Click
    •    Cue

⸻

Current limitation

Because USB 3/4 cannot be accessed directly inside Matrix:

Click and Cue must consume one or more DSP paths.

This reduces available DSP for:
    •    Dual Guitar amps
    •    Bass processing
    •    Vocal processing
    •    Parallel effects
    •    Additional routing

⸻

Proposed Feature

Expose:

USB In 3/4

USB In 5/6

USB In 7/8

as Matrix Mixer sources.

Exactly like USB 1/2.

Each should provide:
    •    Level
    •    Pan
    •    Mute
    •    Solo
    •    Assignment to:
    •    XLR
    •    1/4”
    •    Phones

⸻

Even cleaner implementation

Instead of adding three additional Matrix channels:

Simply allow the existing USB Matrix source to choose its source.

Example:

USB Matrix Source

○ USB 1/2

○ USB 3/4

○ USB 5/6

○ USB 7/8

This would require almost no UI expansion.

⸻

Additional Enhancement

Allow multiple USB Matrix channels simultaneously.

Example:

USB 1/2

Stereo Backing

USB 3

Click

USB 4

Cue

USB 5/6

Playback Stem

Each independently routable.

⸻

Why this matters

The Stadium XL is uniquely positioned to become:
    •    Guitar Processor
    •    Bass Processor
    •    Vocal Processor
    •    USB Audio Interface
    •    Playback Engine
    •    MIDI Show Controller
    •    Monitor Mixer

inside one device.

No additional interface.

No external mixer.

One USB cable.

One pedalboard.

One MacBook.

⸻

Competitive Advantage

Many touring guitarists currently carry:
    •    Guitar Processor
    •    Playback Interface
    •    MIDI Interface
    •    Small Mixer

The Stadium XL already contains almost everything required.

This firmware enhancement would allow many musicians to eliminate:
    •    Additional USB interfaces
    •    Playback mixers
    •    Extra cabling

resulting in:
    •    Faster setup
    •    Fewer failure points
    •    Easier travel
    •    Simpler stage footprint

⸻

Why this fits the Stadium philosophy

The Matrix Mixer already supports multiple non-DSP sources including:
    •    USB 1/2
    •    Bluetooth
    •    Aux
    •    Showcase playback
    •    Click
    •    Count-in

Extending Matrix support to additional USB return pairs would be a natural continuation of this architecture and would greatly enhance the Stadium’s role as a complete live-performance hub.

⸻

Final Thoughts

I’m a professional touring musician building my live show around the Helix Stadium XL. My goal is to use a single USB connection from Cubase to carry:
    •    Backing tracks
    •    Click
    •    Cue tracks
    •    MIDI Program Changes
    •    Snapshot automation

while using the Stadium XL as the only stage processor for guitar, bass, vocals, monitoring, and FOH routing.

This enhancement would make that possible without additional hardware and would elevate the Helix Stadium XL into a class-leading solution for modern live performance.

Thank you for considering this feature request and for continuing to develop such an innovative platform.

 

 

 

 

 

 

[maxxlines]

+1 to this. Fully support this request!

 

As a touring musician running a DAW-automated live setup, this is a massive oversight in the current implementation.

Having to consume valuable DSP blocks just to route USB audio channels like Click and Cue tracks completely defeats the purpose of having a powerful built-in USB audio interface.

Exposing USB 3/4, 5/6, and 7/8 directly to the Matrix Mixer (bypassing DSP entirely) and allowing them to be independently assigned to specific hardware physical outputs (XLR, 1/4" / Sends, and Phones) is crucial. Click and cues must go exclusively to IEMs without touching FOH, and doing that right now needlessly eats up DSP.

The Stadium XL has all the hardware capability to be the ultimate single-cable live performance hub. Huge thanks to the OP for such a clean breakdown. Line 6 / Digital Igloo, please take a look at this — implementing this would allow us to ditch secondary audio interfaces for good!

[silverhead]

This is a very detailed and well explained feature request. It would be a shame for it to go unnoticed by Line 6. Unfortunately, that's what may happen with this post. This is not the official way to submit feature requests.

 

I strongly suggest that both @rikkimadan and @maxxlines submit an official feature request here:

https://line6.com/company/contact/productfeedback/

 

 

[rikkimadan]

I have submitted a request on the product feedback as well. I like to run dual amps and cabs for my setup, all 4 paths are getting used and there is none left for the usb and backing tracks in this scenario. Very limiting indeed...hope this can be fixed in the next update.

[silverhead]

This is not meant to detract from the feature request but the Showcase feature already exists and may address some of the request. You can import the audio stems from your DAW into a Showcase Song. The Song tracks are available in the Matrix Mixer. You can also add a click track and use the various Song Flags to control MIDI and other things. The intention of the Showcase feature is to turn the Helix device into exactly what @maxxlines describes in this quote from him (with no USB cable required):

 

“The Stadium XL has all the hardware capability to be the ultimate single-cable live performance hub.”

[rikkimadan]

I would still prefer to use my DAW Cubase for the backing tracks instead of showcase, that's an additional screen as well. Probably will have to go with an additional sound card only then.

[guix]

Sends should defnitely get a mixer! SPDIFs too! That way you can send the song (or the return of USB  for a DAW) straight into a physical out...

I use Gig perfomer with as synth so I have a separate interface for it and I would definitely use only helix as interface if I could send Gig performers out to the 3/4 sends... 3/4 returns used as IEM In so... there is a nice use for the unused sends!

Probably a mode called Aux out (to copy aux in for IEM in) that turns 3/4 sends into a mixer ... then you select whatever you want to send.

 

[ricksteruk]

I totally agree!  I was dying to use USB inputs and outputs more easily with my OG Helix.. made some feature requests years ago.
Every time I see an update I hope they add this - but sadly no - another amp I likely won't use!

Would be great if the USBs could go on Send / Return blocks as well as Path inputs and outputs.    I have plans!

 

[rikkimadan]

Logically this feature would be the only way a touring musician could think of replacing a sound card , glad others are agreeing on this . A lot my other friends who use other gear are shocked to know that such a basic feature is not available on Helix Stadium . Team Line6 , next firmware update , can please do this or let me know if you are not planning to so maybe i can switch to another brand .