The Radial Catapult RX4M is the mic-optimized isolated receive module of the Catapult family, adding transformer isolation on each channel to prevent ground loops and hum when connecting equipment from different power sources. This isolation is critical in professional live sound where your rack and the stage equipment may be on different electrical circuits. The transformers also provide an additional layer of signal protection for your audio gear.
UnverifiedPower requirement is not verified in the catalog
Catalog estimate
~$375Current listings stay in the price tracker
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
4 channels. 1 cable runs. Outside rack.
The Catapult RX4M is the receive end of Radial's analog Cat5Standard network cable grades. In an audio rig one cheap Cat5e run can replace a 48-channel copper snake; AES50 wants it shielded.snakeA multicore cable bundling many channels into one stage-to-console run. A sub-snake collects one corner of the stage into a drop box. system — it sits in your rack, takes a single RJ45 cable from the stage transmitter, and breaks that run back out into four discrete XLRThe standard 3-pin locking connector for mics and balanced line signals — pin 1 is the shield, pins 2 and 3 carry the balanced pair. male outputs ready to feed your console, playback rig, or IEMIn-Ear Monitor — earpieces that replace floor wedges, feeding each player their own mix. The reason this whole rack exists. rack inputs. The key distinction over the basic receive module is the M: mic-levelThe tiny signal straight out of a microphone — roughly a thousandth of line level. It needs a preamp before anything else touches it.transformer isolationA magnetic coupling that passes audio between two windings with no wire contact — isolates splits and kills ground-loop hum, no power needed. on every channel. That isolation isn't a luxury feature; it's the reason this box exists. Whenever your rack and the stage sources are drawing from different electrical legs — which is most festival situations and a lot of installed venues — you need that galvanic barrier between them or you're fighting hum all night.
The passive, zero-watt draw means this unit asks nothing of your rack's power budget and introduces no noise floorThe constant background hiss a device produces on its own. Everything you pass through it sits on top — lower is better. of its own. At 1.8 kg it's light enough that surface-mount or rear-of-rack placement is realistic even without a full rack shelf, though the catalog lists it as rackmountable. The single RJ45 input is both the elegance and the constraint: one Cat5Standard network cable grades. In an audio rig one cheap Cat5e run can replace a 48-channel copper snake; AES50 wants it shielded. run carries all four channels, so your stage-to-rack run is a single, tug-resistant cable rather than a bundle of XLRsThe standard 3-pin locking connector for mics and balanced line signals — pin 1 is the shield, pins 2 and 3 carry the balanced pair.. The transformer isolationA magnetic coupling that passes audio between two windings with no wire contact — isolates splits and kills ground-loop hum, no power needed. handles not just hum rejection but also provides a degree of protection for downstream gear if something ugly happens on the stage end.
Best fit
Where it earns its place in the system
This belongs in any IEMIn-Ear Monitor — earpieces that replace floor wedges, feeding each player their own mix. The reason this whole rack exists. or monitor rig that regularly works venues where shared grounding is unreliable — festivals, churches, theatres with aging infrastructure, fly-dates where you're plugging into whatever power the house gives you. If you're running the full Catapult system, the RX4M is simply the correct receive-side partner when your sources are mic-levelThe tiny signal straight out of a microphone — roughly a thousandth of line level. It needs a preamp before anything else touches it. signals. If your sources are already at line levelThe strong signal that runs between pieces of gear (about a volt) — hotter than mic level, far below speaker level. and transformer isolationA magnetic coupling that passes audio between two windings with no wire contact — isolates splits and kills ground-loop hum, no power needed. isn't a concern, the standard RX4 saves money. And if you need more than four channels in a single run, you'll be stacking multiple Catapult pairs rather than scaling this unit — plan your channel count before committing to the system.
In the rack
Details worth deciding before load-in.
Label the RJ45 jack on both the TX and RX ends with the same color gaff tape before the gig — Cat5Standard network cable grades. In an audio rig one cheap Cat5e run can replace a 48-channel copper snake; AES50 wants it shielded. cables look identical and getting them swapped at changeover costs time you don't have.
Because the unit draws no power, it can live on a rear shelf or in a non-powered rack bay without any sequencing concerns — but make sure it's physically secured; a dangling RX4M puts strain on the RJ45 connector over a long run of shows.
Run a quality shielded Cat5eStandard network cable grades. In an audio rig one cheap Cat5e run can replace a 48-channel copper snake; AES50 wants it shielded. or Cat6 cable between TX and RX rather than generic Ethernet patch cable — Radial's own Catapult cable or a purpose-built audio snakeA multicore cable bundling many channels into one stage-to-console run. A sub-snake collects one corner of the stage into a drop box. cable will give you better rejection over longer distances on a loud stage.
After patching the four XLRThe standard 3-pin locking connector for mics and balanced line signals — pin 1 is the shield, pins 2 and 3 carry the balanced pair. outputs into your rack, ring out each channel individually before doors to confirm the transformer isolationA magnetic coupling that passes audio between two windings with no wire contact — isolates splits and kills ground-loop hum, no power needed. is doing its job — a quick polarity and hum check takes two minutes and tells you immediately if a cable has a pin issue.
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
1 bank · 4 ch each
Analog over Cat cable
4 × XLR male
01 · Source
Compatible analog-snake transmitter
The matching send end accepts separate analog sources and assigns them to repeatable cable banks.
Required
Compatible transmitter or breakout
Groups
4 source channels
Verify
Matching bank labels
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 · Analog Snake
Use it as analog snake tracked outside rack rails; follow the manufacturer’s mounting and form-factor guidance.
Plan the companion path
Complete both ends with a compatible sender, receiver, or breakout. Match connector, channel wiring, direction, and shielded-cable requirements.
Connector boundary
Documented connectors: RJ45, XLR male. 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 Radial Catapult RX4M
Port
Panel
Connector
Direction
Signal
Channels
Cat5 In
rear
RJ45
input
analog audio
—
XLR Out 1
rear
XLR male
output
analog audio
—
XLR Out 2
rear
XLR male
output
analog audio
—
XLR Out 3
rear
XLR male
output
analog audio
—
XLR Out 4
rear
XLR male
output
analog audio
—
Showing 5 of 5 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.
Catapult RX4MThe Radial Catapult RX4M is the mic-optimized isolated receive module of the Catapult family, adding transformer isolation on each channel to prevent ground loops and hum when connecting equipment from different power sources. This isolation is critical in professional live sound where your rack and the stage equipment may be on different electrical circuits. The transformers also provide an additional layer of signal protection for your audio gear.View gear →
Catapult Rack TXThe Radial Catapult Rack TX is the send-end partner to the Catapult Rack RX: a 1U rack-mount transmitter that takes 12 XLR inputs and sends them over three Cat 5/6 cables (four channels per cable). Drop one in your FOH, monitor, or playback rack and run Cat 5/6 to the stage end for a complete transformer-isolated 12-channel analog snake — dramatically lighter and cheaper than a traditional copper multicore. Passive, no power required.View gear →
Catapult TX4LThe Radial Catapult TX4L adds line-level isolation transformers to the Cat5 snake system, letting you split playback tracks or console outputs to two destinations with the isolated side immune to ground loops. It is built for playback rigs feeding both FOH and a broadcast or recording split, where hum from tied grounds is the classic failure. Works with any Catapult receive module over one shielded Cat5 run.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.
Where does the Radial Catapult RX4M live in a complete rig?
The catalog assigns it no rack units. Builder tracks it as non-rack gear; follow the manufacturer’s mounting, case, and form-factor guidance.
How much power does the Radial Catapult RX4M draw?
Its power requirement is not yet verified in the catalog.
What connections does the Radial Catapult RX4M have?
5 documented physical ports, including Cat5 In, XLR Out 1, XLR Out 2, XLR Out 3, XLR Out 4.
07 · See this gear inside a complete system plan.
Builder preview
Builder keeps non-rack gear in the same bill of materials, budget, dependency, and connection plan as the rack-mounted system around it.Open in Builder
