Radial Catapult RX4M
Radial·Model Catapult RX4M·radial-catapult-rx
Photos
Manufacturer product photography — the drawn faceplate above stays true to panel layout; these show the hardware itself.
About the Radial Catapult RX4M
The Radial Catapult RX4M is the mic-optimized isolated receive module of the Catapult family, adding 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 each channel to prevent ground loopsHum from gear seeing two ground paths at slightly different voltage — the classic buzz when two racks share audio and power. 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.
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.
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
- 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.
4-channel Cat5Standard network cable grades. In an audio rig one cheap Cat5e run can replace a 48-channel copper snake; AES50 wants it shielded. receive module with 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. (RX4M).
I/O Ports (5)
| Port | Connector | Direction | Signal | Channels |
|---|---|---|---|---|
| Cat5 In | RJ45 | input | analog audio | — |
| XLR Out 1 | XLR MALE | output | analog audio | — |
| XLR Out 2 | XLR MALE | output | analog audio | — |
| XLR Out 3 | XLR MALE | output | analog audio | — |
| XLR Out 4 | XLR MALE | output | analog audio | — |
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Rack space, watts, weight and every connector, side by side.
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