The Behringer X32 (and its sibling Midas M32) is the most- deployed digital mixer in worship, club-tour, and small- venue land. Setting up IEM mixes on it isn’t hard, but the path isn’t obvious from the front panel either. This guide walks through the routing decisions in order: pick a bus type, link it stereo, set pre-fader, route to a physical output, limit, save.

Why Mix Bus 1–16 (not Main)

The X32 has 16 mix buses (Mix Bus 1 through 16), 6 matrix buses, the main L/R, and a centre/mono bus. For IEMs you want Mix Bus 1–16. Reasons:

They’re plentiful — 16 buses means up to 16 mono mixes (or 8 stereo).
They can be set pre-fader, which is what you want for monitors so FOH fader moves don’t affect the IEM mix.
They route freely to any physical output, Ultranet, or AES50.
Matrix buses are post-Main, which means they reflect FOH changes — wrong source for monitors.

Step 1: Link buses into stereo pairs

Stereo IEMs need a left and a right send. By default the 16 mix buses are independent mono. To make a pair stereo:

Press Setup on the console.
Navigate to Channels & Buses.
Scroll to the Mix Bus Config section.
For each adjacent pair you want stereo (1+2, 3+4, etc.), set the link state to linked.

After linking, the pair shares pan, mute, and fader. Sending a vocal mic to it with pan 0 puts it dead center in both ears, pan -100% puts it hard left, +100% hard right.

Step 2: Pre-fader vs post-fader

Every mix-bus send on every channel has a Pre/Post toggle. For monitors: pre-fader.

Pre-fader (PRE) — the send level to the monitor bus is unaffected by the channel’s main fader. FOH can pull the lead vocal down in the house and the drummer’s monitor mix doesn’t change.
Post-fader (POST) — the send level follows the main fader. Useful for sub-mixes and effects, not for monitors.

Select the channel you want to send.
Press Sends on Faders for the target bus.
Bottom-right of the screen → toggle each bus to Pre EQ, Pre Fader, or Post Fader. For monitors, Pre Fader is the standard pick.

Step 3: Route the bus to a physical output

Linking and pre-fader-setting a bus doesn’t make audio appear at any jack. You have to route the bus to a destination:

Option A: Route to Ultranet / P16

Each X32 sends 16 channels of Ultranet out a single RJ45 jack on the back, ready to feed a chain of P16 personal mixers. To send a mix-bus pair to Ultranet:

Press Routing.
Go to the P16-Out tab.
Assign your stereo mix-bus pair to the Ultranet channels your performers will dial up on their P16Ms.

Option B: Route to physical XLR aux outputs

On the back of the X32 are 8 XLR aux outputs (or 6 + Main L/R on some models). To send a mix-bus pair to two of them:

Press Routing.
Go to the Out 1-16 tab.
Assign Out 1 = Mix 1, Out 2 = Mix 2 (or wherever your pair lives).

From the back-panel XLRs, run two cables to a stereo IEM transmitter (e.g. Shure PSM900 or Sennheiser EW IEM G4).

Option C: Route to AES50 (to a stage box)

If your IEM transmitters are over at the monitor world rack and you’re using a digital stage box (e.g. Behringer S16) to get there, route the buses to AES50 channels instead of physical XLR. Same routing screen, different output column.

Step 4: Add a bus-level limiter

Every IEM mix bus should have a brick-wall limiter on it so a cable short or feedback squeal can’t exceed safe listening levels in a sealed ear. On the X32:

Select the bus (push the bus’s Sel button).
Open the Dynamics tab on the bus.
Set Compressor to Compressor mode = LIM, ratio ∞, threshold around -6 dBFS, attack 0.1 ms.

Full discussion of where to put the limiter and what thresholds make sense is in IEM limiters and hearing protection.

Step 5: Save it

Press Setup → Show / Scenes.
Save the current state as a scene (e.g. “Sunday Service Base”).
Make a “Recall Safe” setting that includes the bus routing + linking but excludes per-channel sends so a band-specific scene can override the channel mix without wiping your monitor structure.

Bus pre-show checklist

All IEM bus pairs linked stereo.
All channel → IEM bus sends set Pre Fader.
Each bus routed to its physical destination (XLR / Ultranet / AES50).
Each bus has its limiter on with threshold <-3 dBFS.
Scene saved with a clear name.

Plan the rest of the rack

Drop the X32 + IEM transmitters + stage box into IEM Rig; the auto-wire engine connects bus outputs to transmitter inputs and exports the patch sheet.

Setting Up Stereo IEM Mixes on an X32 / M32