The Sennheiser AC 41-US combines four IEM transmitter outputs onto one antenna, the standard move once an evolution wireless G4 monitor rack grows past two channels. Active gain stages make up the combining loss so the radiated power stays useful, and units cascade for larger systems. Half-rack chassis pairs with Sennheiser rack hardware.
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01 · What it does—and what that changes in your rig.
Product overview
Start with the payoff, then work through how it functions, where it fits, and the details that change a real build.
The payoff
Antenna Distro decisions, organized around the whole rig.
The AC 41-US exists to solve one specific problem: you have more than one or two Evolution Wireless G4 IEMIn-Ear Monitor — earpieces that replace floor wedges, feeding each player their own mix. The reason this whole rack exists. transmitters and you don't want a separate antenna hanging off the back of each one. It takes up to four transmitter antenna outputs and combines them into a single feed going to one antenna — or one run of coax to a remote antenna position. That's the whole job, and it does it cleanly. The half-rackThe standard slice of rack height: 1U = 1.75″. A 3U box takes three slices; half-rack gear pairs two units side by side in one. chassis means it pairs with a second unit or a Sennheiser half-rack filler in a single rack space, keeping the build tidy.
Documented outputs
1One destination connection
Documented inputs
5Based on documented inputs
Rack space
1U · half-rackBuilder checks available rail space
Photo: Sennheiser1U · half-rack · 6W
Function
How it works in the path
The active part matters here. Passive combining loses signal — you can't sum four RFRadio Frequency — the wireless part of wireless. RF planning is why big rigs scan, coordinate, and combine antennas instead of hoping. paths without paying a combining loss, typically several dB. The AC 41-US uses active gainHow much the preamp amplifies the incoming signal. Too low and you’re hunting through hiss; too high and peaks clip. stages to compensate, so what reaches your antenna stays at a useful level rather than a diminished one. At 6 watts nominal draw and a shallow 150mm depth, it won't stress a standard power conditionerFilters venue AC, clamps surges, and gives the rack one tidy inlet. Not a voltage regulator and not a battery — just cleaner power. or fight for space in a tight rack. The cascade capability means that when you grow past four transmitters, you can chain combinersThe transmit-side twin of a distro: merges several IEM transmitters into one antenna without letting them intermodulate. rather than rethink your whole antenna strategy.
Best fit
Where it earns its place in the rack
If you're running two G4 transmitters, you probably don't need this — the individual transmitter antennas will do fine and you're adding complexity for no gainHow much the preamp amplifies the incoming signal. Too low and you’re hunting through hiss; too high and peaks clip.. Where the AC 41-US earns its place is the three- or four-channel IEMIn-Ear Monitor — earpieces that replace floor wedges, feeding each player their own mix. The reason this whole rack exists. rack, or any situation where you need to centralize your antenna runs to a single point of control: a distroOne pair of antennas feeding many receivers through an amplified splitter — replaces the forest of whips and keeps RF levels consistent. mast, a house antenna position, or a shared antenna run with a padded splitter downstream. It's purpose-built for the Evolution Wireless ecosystem, so if your transmitters are a different manufacturer's gear, look at that manufacturer's combining solution first.
In the rack
Details worth deciding before load-in.
Run the single Antenna Out to your highest-gainHow much the preamp amplifies the incoming signal. Too low and you’re hunting through hiss; too high and peaks clip. antenna or paddleA directional antenna (paddle, LPDA, helical) aimed at the stage — focuses coverage where the performers are and rejects RF from elsewhere. position — you've already paid the combining tax, so don't also pay for a poor antenna placement.
Label each TX In port at patch time with the corresponding transmitter channel number. Four identical BNCThe twist-lock coax connector used for word clock and antenna runs — it locks, so it can’t be pulled out mid-show. inputs look the same at 2am when you're troubleshooting a dropoutA brief audio gap when the radio link fails — the thing diversity, distros, and coordination all exist to prevent..
If you're cascading two AC 41-US units for an eight-transmitter rig, the second combinerThe transmit-side twin of a distro: merges several IEM transmitters into one antenna without letting them intermodulate.'s output feeds one of the first unit's TX inputs — confirm your total path loss and active gainHow much the preamp amplifies the incoming signal. Too low and you’re hunting through hiss; too high and peaks clip. budget before assuming radiated power is still adequate at the talent position.
Pair it with the Sennheiser rack mounting hardware to fill the full rack unitThe standard slice of rack height: 1U = 1.75″. A 3U box takes three slices; half-rack gear pairs two units side by side in one. cleanly; a loose half-rack unit rattling around on one side of a shelf is a vibration and connector-stress problem waiting to happen on a touring rig.
02 · Know the whole path before you buy.
Signal path
Learn the route as a block diagram: source, product function, transport, and destination. Select any block to see what enters, what changes, and what leaves.
Interactive block diagramAuto-looping · hover, focus, or tap to hold a stage
Port-type signalProduct functionSystem boundary
Follow one signal from source to destination
Each block answers the same three questions: what arrives, what changes here, and what leaves.
01 · Source · selected
bnc + dc barrel
bnc
01 · Source
5 documented inputs
bnc + dc barrel
Arrives as
5 documented inputs
Connector
bnc + dc barrel
Signal
antenna
03 · What this product asks of the rest of the system.
Compatibility
Treat connector names as the start of the check—not the answer. These are the boundaries that determine a complete working path.
Best fit · Antenna Distro
Use it when 1U · half-rack and 150 mm of depth fit the case.
Plan the companion path
Complete the path with upstream and downstream gear that matches connector, direction, signal type, protocol, and wiring standard.
Connector boundary
Documented connectors: bnc, dc barrel. Match connector, direction, and signal type—not shape alone.
04 · Every connector, grouped by job.
I/O ports
Switch the product view and the documented port inventory updates with it—hardware and data stay side by side.
Every connector, grouped by job.
Switch panels to keep the hardware view and the documented port list in sync.
Front panelRear panel
All documented ports for Sennheiser AC 41-US Antenna Combiner
Port
Panel
Connector
Direction
Signal
Channels
TX 1 In
rear
bnc
input
antenna
—
TX 2 In
rear
bnc
input
antenna
—
TX 3 In
rear
bnc
input
antenna
—
TX 4 In
rear
bnc
input
antenna
—
Antenna Out
rear
bnc
output
antenna
—
DC In (NT 3-1)
rear
dc barrel
input
power
—
Showing 6 of 6 documented physical ports.
05 · Compare the decision, not just the price.
Alternatives
The rows are organized around fit, power, I/O, and system role so a cheaper unit cannot hide a more expensive workflow.
AC 41-USThe Sennheiser AC 41-US combines four IEM transmitter outputs onto one antenna, the standard move once an evolution wireless G4 monitor rack grows past two channels. Active gain stages make up the combining loss so the radiated power stays useful, and units cascade for larger systems. Half-rack chassis pairs with Sennheiser rack hardware.View gear →
ASA 1/NTThe ASA 1/NT is Sennheiser's higher-capacity antenna splitter with eight outputs per side and built-in Ethernet for remote monitoring via Sennheiser's Wireless Systems Manager software. It is purpose-built for larger Sennheiser wireless deployments where you need to monitor RF status and antenna performance from FOH or a network dashboard. The Ethernet connectivity is a significant step up from the ASA 214 for production teams that need visibility into their RF environment.View gear →
ASA 214The ASA 214 is Sennheiser's entry-level antenna distribution solution, designed specifically for their Evolution Wireless and 2000 series receivers. It provides four outputs per antenna with active gain compensation, making it the right choice when you are running multiple Sennheiser wireless channels from shared antennas. If you are in the Sennheiser ecosystem, this is simpler and more cost-effective than using a third-party distro.View gear →
EW-D ASAThe Sennheiser EW-D ASA is the current-generation antenna splitter for Evolution Wireless Digital, feeding four EW-D or EW-DX receivers from one antenna pair and powering them over the included DC leads. It replaces the legacy ASA 1 and ASA 214 in new systems, and two units cascade for eight-channel racks. Sold as a kit with power supply and eight BNC interconnects.View gear →
06 · Resolve the questions that can change the purchase or build plan.
Planning questions
Short, source-backed answers surface rack fit, power, cabling, and connection details before they become surprises.
How will the Sennheiser AC 41-US Antenna Combiner affect rack fit and case depth?
It occupies 1U · half-rack. Its documented depth is 150 mm.
How much power does the Sennheiser AC 41-US Antenna Combiner draw?
Typical draw is 6W and documented maximum draw is 9W.
What connections does the Sennheiser AC 41-US Antenna Combiner have?
6 documented physical ports, including TX 1 In, TX 2 In, TX 3 In, TX 4 In, Antenna Out, DC In (NT 3-1).
07 · See this unit inside a real rack plan.
Builder preview
Placement is only the start. Builder checks space · depth · weight, power headroom, dependencies, and compatible signal paths around this exact catalog item.Open in Builder
