Motorola APX • Tactical Audio Hub
MSM — Motorola APX / MOTOTRBO (M9)
Modular Speaker Mic for Motorola APX and MOTOTRBO XPR-series radios using the GCAI multi-pin accessory connector. The APX connector carries full accessory data — emergency, programmable button, and volume control are all live. Plug in a tactical headset and the auto-Nexus port turns this into a PTT hub.
How It Works
☑ Patrol Mode
Use as a standard speaker mic. Clip to shoulder strap or vest. Omni-directional microphone captures voice from any angle — no need to lean into the mic.
☑ Tactical Mode
Plug a headset into the Nexus port. Speaker auto-mutes. Audio routes to your ears. The MSM becomes your PTT — press front or side button to transmit through the headset mic.
Key Features
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Dual-Role Operation: Use as a standalone speaker mic for daily patrol. Plug a headset into the Nexus port and the MSM becomes a PTT — speaker auto-mutes, audio routes to your ears. One device, two modes.
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Dual PTT: Oversized front button for quick keying plus a secondary side button — both work with gloved hands.
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Emergency Button: Dedicated bright-orange emergency activation button. Sends the radio's programmed emergency alert when pressed.
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Volume Control: Up/down scroll buttons on the speaker mic body — adjust audio without reaching for the radio.
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Programmable Button: One additional programmable button configurable through radio CPS for channel change, monitor, scan, or other radio-specific functions.
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Amplified Nexus Port: NATO-wired Nexus connector with built-in amplification for low-impedance dynamic headsets — Ops-Core AMP, 3M Peltor ComTac, MSA Sordin, David Clark, and other tactical headsets with U-174/U plug. Speaker auto-mutes when headset is connected.
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IP67 Sealed: Dust-tight and submersible to 1 meter for 30 minutes. Built for rain, mud, and standing water.
Radio-Specific Notes
Provides the same accessory-side functionality as Motorola IMPRES speaker mics — emergency button, programmable button, volume down/restore — at a competitive price point with the added Nexus headset port.
Compatible Radios
Motorola APX 900, APX 1000, APX 2000, APX 3000, APX 4000, APX 5000, APX 6000/XE, APX 7000/XE, APX 8000/XE, APX NEXT, XPR 6100, XPR 6300, XPR 6350, XPR 6380, XPR 6500, XPR 6550, XPR 6580, XPR 7350/e, XPR 7550/e, XPR 7580/e, SRX 2200.
Headset Compatibility
The amplified Nexus port is designed for headsets with dynamic (low-impedance) microphones:
- ✓ Ops-Core AMP (via U174 Monaural or Monobinaural Downlead)
- ✓ 3M Peltor ComTac V/VI, SWAT-Tac
- ✓ MSA Sordin Supreme Pro-X (Mil-Spec)
- ✓ David Clark H10-76 series
- ✓ Any NATO-wired headset with U-174/U plug and dynamic microphone
Electret microphone headsets are not supported by this amplified variant. Contact us for electret-compatible custom orders.
Need a PTT Without a Speaker Mic?
The MSM is built for operators who need both modes — speaker mic on patrol, headset PTT on operations. If you run a tactical headset full-time and don’t need a speaker mic at all, the Constant Able is a lighter, simpler, purpose-built PTT.
Constant Able PTTs connect directly to your radio with no speaker mic in the chain. Auto-switching impedance detection handles both dynamic and electret headsets automatically — broader headset compatibility than the MSM’s dynamic-only Nexus port. Available for Motorola APX, Motorola XTS, Kenwood, L3Harris, Hytera, Icom, Baofeng, and NATO 6-pin radios.
Specifications
| Spec |
Value |
| Radio Connector |
Motorola GCAI (Multi-Pin) |
| Headset Port |
Nexus (U-174/U) — Auto-Nexus |
| Earpiece Port |
3.5 mm listen-only |
| Microphone |
Omni-directional, −42 dB ±3 dB |
| Speaker |
36 mm dynamic, 1 W (1.5 W max), 91 dB ±3 dB |
| PTT |
Dual — oversized front + secondary side |
| Emergency |
Dedicated button (bright orange) |
| Volume |
Up / Down scroll control |
| Programmable |
1 programmable button |
| IP Rating |
IP67 (dust-tight, 1 m submersion / 30 min) |
| Cable |
Kevlar-reinforced coil cord, 50,000 flex cycles, 13 kg pull strength |
| Temp Range |
−25°C to +60°C operating |
| Frequency Range |
580 Hz – 5 KHz |
| PTT Switch Life |
100,000 cycles |
| DISCO32 SKU |
MSM-50-MT9-04 |
DISCO32 Tactical Antennas — Aberdeen, NC
Amplified/Modified by DISCO32 • 1-Year Warranty
