Brand:

• Crown

Models:

• CTD-2125
• CTD-4125
• CTD-8125

Overview:

ComTech D Series amplifiers support Dante® audio networking and multiple Ethernet operating modes.  Each amplifier includes two physical Ethernet connectors identified as Port A and Port B.  Selecting the appropriate network mode and understanding port behavior helps ensure reliable audio performance and predictable system operation.

Ethernet Port Identification

ComTech D Series amplifiers include two Ethernet ports:

• Port A – First Ethernet port on the amplifier

• Port B – Second Ethernet port on the amplifier

An onboard WebUI for configuration, control and monitoring is available on both Port A and Port B in all modes, assuming no network errors have occurred.

Network Mode and Port Usage

Split Mode

• Port A is used for HControl

• Port B is used for Dante Primary audio

In Split mode, Port A and Port B should be connected to different IP subnets.  This mode is intended for systems where control traffic and Dante audio traffic are intentionally separated.

Redundant Mode

• Port A is used for Dante Primary audio and HControl

• Port B is used for Dante Secondary audio

In Redundant mode each port connects to an independent Dante network to provide audio redundancy.

Switched Mode

• Port A and Port B are connected to single ComTech D Series IP address.  The internal hardware acts as a network switch connecting the ComTech D Series and its external Ethernet ports. 

In Switched mode, the single IP address may be used for Dante Primary audio, HControl, and the WebUI.  This mode is intended for daisy-chaining network connections to additional devices. A maximum of 4 daisy-chained devices is supported. 

IP Addressing Best Practices

Use DHCP or static IP addressing whenever possible. Confirm required subnet separation when using Split or Redundant modes.
After making network configuration changes, click the Confirm or Apply and Reboot button at the bottom of the screen for the changes to take effect.

When the IP address is set to DHCP and no DHCP server is present

• The HControl port defaults to the standard Link-Local IP range of 169.254.0.0/16
• The Dante Primary port defaults to the standard Link-Local IP range of 169.254.0.0/16
• The Dante Secondary port defaults to an alternative Link-Local IP range of 172.31.0.0/16

AES67 Best Practices

AES67 is an Audio over IP interoperability standard. When enabled on a Dante device, AES67 allows audio exchange with non‑Dante, AES67‑compatible devices using RTP multicast audio streams.
Dante audio behavior is unchanged when AES67 is enabled, it is required only for interoperability with non‑Dante devices. 

• AES67 support is optional on ComTech D Series amplifiers, and configuration is performed entirely in Dante Controller.
• Enable AES67 only when interoperability with non‑Dante AES67 devices is required. For systems using only Dante‑enabled devices, AES67 does not need to be enabled.
• Dante‑to‑Dante audio performance, latency, and clocking are not affected by AES67.
• For reliable AES67 operation:
  • Use RTP multicast addresses in the 239.x.x.x range for AES67 audio streams.
  • Confirm RTP multicast address prefixes match between transmitting and receiving devices.
  • If address prefixes do not match, a subscription may appear successful but audio may not pass.
• When a device is enrolled in a Dante Domain, AES67 configuration is managed by Dante Domain Manager.

Dante Software Information

ComTech D Series amplifiers use the Dante Embedded Platform (DEP).  The Dante version shown in Dante Controller may differ from Dante hardware devices and does not indicate a compatibility issue.  Dante updates are delivered only as part of the ComTech D Series amplifier firmware.

Summary

Understanding ComTech D Series Ethernet port naming and network mode behavior helps ensure correct installation and predictable ComTech D Series system operation.  Always verify the selected network mode and intended use of Port A and Port B during system design and commissioning.