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The HKB-2X speaker station is a 4-gang flush-mountable user station.


Speaker Station

  • Easy to use front panel with OLEDdisplays & backlit keys
  • Headset or hands free support withspeaker and mic
  • 2 Keysets assignable to channels
  • Shift page for 4-channel operation
  • Program Audio level control
  • Display swivels for optimal viewingangles


  • Ethernet Network port with PoE(1)
  • Powerline terminal plug to HMS-4X(2/3)


  • 4-gang for flush mounting
  • Optional S-MOUNT for desktop use

The HelixNet System

  • Wired Partyline - Networked
  • Hosted by Arcadia or HMS-4X(3)
  • Up to 24 Channels – Licensed
  • Up to 64 HelixNet Endpoints
  • Program Audio user level control

Effortless Management 

  • Easy to use CCM browser configuration
  • Fast front panel control & configuration
  • Central discovery & pairing on Arcadia
  • Plug-and-go Powerline to HMS-4X(2/3)
  • Central firmware upgrades from host

Footnotes:(1)CCM and Endpoint network connection to HMS-4X requires HLI-ET2(2)XLR Powerline connections is not available for Arcadia. Contact Clear-Com for further information.(3)HMS-4X is a legacy product as of 2022

*Note: HMS-4X is a Legacy Product as of 2022. Please check for availability.

Item Code




(4) 6-32 x 1/2\" mounting screws (280038Z)

(4) Screw cover (416G054)

(1) Terminal block connector for powerline (210085Z)

(1) Terminal block connector for DC power (210369Z)

Optional Accessories (sold separately):

S-MOUNT Wall adapter

PSU 15W 48V DC (453G025)

Inline PSU 15W 48V DC (453G026)


HelixNet System Hosts

Arcadia: Supports up to 64 HelixNet endpoints (HRM-4X, HKB-2X & HXII-BP) over Ethernet. Up to 24 Channels can be HelixNet Enabled using a Licensed Port for assignment to any HelixNet endpoints keyset.

HMS-4X: Supports up to 64 endpoints (HRM-4X, HKB-2X, HBP-2X, HXII-BP, HLI-2W2, HLI-4W2, LQ port). User stations can connect via HMS’s 2 Powerlines (see datasheet for limits) or over Ethernet via optional HLI-ET2 module. HMS allows use of 12 channels which can be expanded to 24 using optional license.


Powerline**: Powerline, Terminal Block 5 pole, 5mm pitch

Ethernet/PoE *: RJ45

Headset: 4-pin XLR–M or 7-pin XLR-M with (2) PTT GPI (-X7)

Gooseneck Mic: 3-pin Tuchel

Power Connector: Terminal Block 2 Pole, 5mm

Microphone Pre-amplifier

Headset Mic Impedance: 200Ω (Dynamic)

Headset Mic Voltage: 1.7V (Electret selectable)

Limiter: +23dB

Route to four-wire output at 0dBu out:

Mic Gain: 60dB (Dynamic), 45dB (Electret)

Frequency Response: 300Hz - 10 kHz ± 3dB, contoured for intelligibility

Distortion: <0.1% THD @ 1kHz

Noise: <-65dBu

Headphone Limiter: 0dB (selectable)

Headphone Amplifier

Load Impedance: >32Ω 

Output Level: +12dBu before clipping

Sidetone: -12dB (selectable)

Route from a four-wire input at 0dBu in: Max Gain: 0dB

Frequency Response: 40Hz - 10kHz ±3dB

Distortion: <0.1% THD @ 1kHz

Noise: -65dBu

Headphone Limiter: 0dB (selectable)

Loudspeaker Amplifier

Load Impedance: 8Ω 

Output Level: +18dBu before clipping

Route from a 4-wire input at 0dBu in: Max Gain: 18dB

Frequency Response: 200Hz - 10kHz ±3dB

Distortion: <0.1% THD @ 1kHz

Noise: <-50dBu

Logic Inputs - PTT/GPI (-X7 only)

Assignable to talk, call, mic and headset keys

Input: 2

Style: Powered input, close contact to ground

Detection Voltage (Min): 3V

Input Voltage (Max): 5V

Output Voltage: 5V

Output Current (Max): 1mA

Device Power

Voltage: 48V DC

Current (Max): 0.3A

Power (Max): 14.4W

BTU (Max): 49BTU/hr

Input Power Connector: Terminal Block 2 Pole, 5mm

This unit can be powered via:

AC Adapter - Wall (not included)

Input Voltage Range: 100 - 240V AC

Input Frequency Range: 50 - 60Hz

Input Power Connector: Universal

Output Voltage: 48V DC

Output Power (Max): 15W

Output Power Connector: KPPX-3-P

PoE - Power over Ethernet

IEEE 802.3af-2003 - Class 0

PSE: 15.4W DC max @ Power Source Req.

PD: 12.95W DC max @ Powered Device Draw

Powerline**: Input Voltage: ±29.5V DC

Input Current (Speaker Off): 0.3A

Input Current (Max): 0.5A

Powerline Utilization: HKB (Local Power) = 1 beltpack HKB (Speaker Off) = 2 beltpacks HKB (Speaker On) = 3 beltpacks

Note the maximum Powerline capacity of the HMS-4X. Use HelixNet Cable Calculator to validate load and cable distance.


32º - +113ºF (0 - +45ºC) 90% relative humidity


4-Gang NEMA, 4.5 x 8.2 x 2.4in (HxWxD)

(114 x 209 x 61mm)


18.8oz (0.53kg)

Network Specifications (Firmware Version 4.2+)
Network Protocols

Ethernet IPv4 – Unicast Audio and Control

mDNS – Multicast Device Discovery Layer 3-Routable with mDNS function limitations

HTTP-Management RTP-Audio Transport WavPack – Audio Codec

Network Ports


Port 80 TCP – System Management

Port 6001 TCP – System Management

Port 6001 UDP - Audio Streams

Multicast: Port 5353 UDP – mDNS, Names, Discovery, Linking Optional for device names and linking

Network Parameters

HMS-4X Endpoint Resource Use: 1

Bandwidth: 300 (max) kbps from each HKB to HMS 1200 (max) kbps from HMS to HKB

Network Jitter Tolerance: <= 128ms jitter buffer per audio stream receiver automatically adjusted to network performance

QoS tags: DSCP=41, Assured Forwarding (AF)

Link-Local Default IP address range:

System reserved IP range: for endpoints

Recommended Ethernet Switches

• Managed Ethernet Switch – Layer 3

• 100/1000 Base-T ports for endpoints

• 1000 Base IP Trunks between switches

• QoS configuration • Energy Efficient Ethernet bypass option

• IGMP Snooping bypass option

Please refer to the Clear-Com HelixNet Network Guide for additional switch settings and network characteristics. *Ethernet to HMS-4X requires HLI-ET2 **Not available for Arcadia. Contact Clear-Com

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