RDL RU-MX4 – 4-Channel Mic/Line Mixer with Phantom
RDL RU-MX4 – 4-Channel Mic/Line Mixer with Phantom is backordered and will ship as soon as it is back in stock.
RDL RU-MX4 – 4-Channel Mic/Line Mixer with Phantom
What is the RDL RU-MX4?
The RDL RU-MX4 is a professional 4-channel mixer that combines balanced microphones and unbalanced line sources. Each input accepts an XLR microphone or an RCA line source, with switchable 24 V phantom for each mic input. A switchable mic or line XLR output, an unbalanced line output and an integral compressor/limiter make it a complete small-system mixer. It suits conference rooms, training rooms and houses of worship that need user-adjustable levels in a compact RACK-UP module.
How does it work?
Each MIC input accepts dynamic or condenser microphones, and the PHANTOM switch below each input enables phantom voltage and sets the optimum gain range. An integral high-pass filter rolls off frequencies below 80 Hz on the mic inputs. A separate unbalanced DIRECT input sums an external source into the mix, and the RCA LINE OUTPUT of one mixer can feed the DIRECT input of another to expand the channel count. The balanced XLR output switches between mic and line level and can be used at the same time as the unbalanced RCA output. Front-panel controls set each level, and each input has a dual-LED VU meter while the final mix shows on an LED string meter. A rear-panel switch inserts a soft-knee compressor/limiter that holds an average +4 dBu output for signals up to 20 dB too hot. The RU-MX4 output is electronically balanced, and a transformer-isolated version is available as the RU-MX4T. Up to three mixers fit in one rack unit with an RDL rack adapter such as the RU-RA3R. RDL recommends the PS-24AS power supply for the USA or the PS-24AX for international installations; the supply is not included.
What are the key features?
- Four mic/line inputs — Each channel takes an XLR microphone or an RCA line-level source.
- Per-input 24 V phantom — A PHANTOM switch on each input powers condenser microphones and sets the gain range.
- Switchable XLR output — The balanced output switches between mic and line level.
- Expandable mixing — DIRECT input and line output let several mixers chain together.
- Compressor/limiter — A switchable soft-knee compressor keeps output levels under control.
- Full metering — Per-input VU meters and an LED string mix meter simplify level setting.
Where is it typically used?
- Conference room
- Training room
- House of worship
- Multi-purpose room
- Boardroom
Technical Specifications
| Model | RU-MX4 |
| Microphone Inputs (4) | 2 kΩ balanced, switchable 24 V phantom (IEC 61938: 2013) |
| Mic Input Level for +4 dBu output | -58 to −20 dBu (PHANTOM OFF or ONHI gain); -41 to −4 dBu (PHANTOM ON LO gain) |
| Line Inputs (4) | 2 kΩ unbalanced |
| Line Input Level | -25 dBV to +20 dBV for +4 dBu output; -10 dBV nominal |
| Gain Adjustments (5) | Mic: Off to 62 dB gain (PHANTOM OFF); Off to 62 dB gain (PHANTOM ON HI GAIN; Off to 46 dB gain (PHANTOM ON LO GAIN); Line: Off to 27 dB gain |
| Output Attenuator | 0 dB to infinity |
| Frequency Response – Mic | 80 Hz to 30 kHz (+/- 1.5 dB), <-10 dB @ 20 Hz (integral high-pass filter) |
| Frequency Response – Line | 20 Hz to 30 kHz (+/- 0.25 dB) |
| THD+N – Mic | < 0.1% (80 Hz to 20 kHz) |
| THD+N – Line | < 0.02% |
| Residual Noise (below +4dBu output) | 4 line level sources (unity gain): < -82 dB (wideband) |
| 40dB Gain, LO GAIN | Mic: -79 dB; all 4 mic level sources: < -73 dB (wideband); < -76 dB (“A” weighted) |
| 50dB Gain, HI GAIN | Mic: -79 dB; all 4 mic level sources: < -73 dB (wideband); < -76 dB (“A” weighted) |
| 60dB Gain, HI GAIN | Mic: -70 dB; all 4 mic level sources: < -64 dB (wideband); < -66 dB (“A” weighted) |
| Outputs (2) | +4 dBu 150 Ω balanced (switchable MIC or LINE); -10 dBV unbalanced |
| Indicators (18) | Dual-LED VU meter for each input; COMPRESSION/LIMITING active LED; POWER LED; 8-segment bar mode string LED audio mix level meter, 0 dB = +4 dBu; VU ballistic: -20 dB, -10 dB, -6 dB, -2 dB, 0 dB, +3 dB; Peak reading: +8 dB,+12 dB |
| Power Requirement | 24 Vdc @ 150 mA, Ground-referenced |
| Overall Dimensions | Height: 1.7 in. 4.3 cm; Length: 5.8 in. 15.0 cm |
Frequently Asked Questions
Can several RU-MX4 mixers be combined?
Yes. The unbalanced LINE OUTPUT of one mixer can feed the DIRECT input of another to expand mixing capacity.
Does it provide phantom power?
Yes. 24 V phantom (IEC 61938: 2013) is switchable on each microphone input.
What does the compressor do?
When switched in, the soft-knee compressor/limiter begins acting about 6 dB below normal output and maintains an average +4 dBu output for signals up to 20 dB too hot.
What power does it need?
24 Vdc at 150 mA, ground-referenced. RDL recommends the PS-24AS power supply for the USA or the PS-24AX for international installations; the supply is not included.
How is it mounted?
RDL lists RACK-UP mounting accessories including the RU-RA3R, RU-HRA1, RU-SMA1, RU-BR1, RC-1UR, UC-1R, UC-2R and WDG1R, plus the DRA-35R DIN rail adapter.
What warranty does the RU-MX4 carry?
This product is covered by a 7-year RDL warranty. For warranty claims, RMAs or support, contact Creation Networks at (888) 230-3661 or sales@creationnetworks.net.
Can Creation Networks help integrate the RU-MX4?
Yes. Creation Networks supports system design, equipment selection and installation planning for RDL products nationwide. Call (888) 230-3661 for a quote or technical help.
At Creation Networks, we do everything we can to create an excellent customer experience. This includes fast shipping and easy returns.
- Most in-stock orders placed Monday-Friday ship within 24-48 hours. General restrictions apply; please see our full shipping policy here.
- We offer a 30-day return policy from the delivery date on many products. Product restrictions apply. Restocking fees for the return of open-box items. Please see our full return policy here for more information.
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