Crown Audio CTD-4125 ComTech D Series is a versatile four-channel Class-D amplifier designed for professional installed audio applications. Delivering 125 watts per channel when all four channels are driven equally, it offers a total of 500 watts with flexible asymmetrical power sharing, allowing the four channels to distribute the available power in virtually any ratio.

The CTD-4125 features built-in 24-bit DSP operating at 48 kHz, allowing outputs to be customized for room acoustics and speaker performance. Factory JBL SpeakerTunings are included for select JBL models, including Control 400 Series ceiling speakers. Dante and AES67 network audio connectivity, Lo-Z/Hi-Z switchable outputs, pilot tone and load monitoring, source priority switching, and a GPIO interface provide additional flexibility.

Designed for convenient installation, the Crown Audio CTD-4125 features a compact 1RU, half-rack-width form factor that can be mounted in a rack, under a table, or on a wall using the included mounting hardware. It operates on 100–240V AC at 50/60 Hz and uses convection cooling for quiet operation.

Key Features

• Delivers 4 × 125W output with flexible 500W power sharing.
• Supports 4/8-ohm and 70/100V speaker systems.
• Features Dante and AES67 network audio connectivity.
• Includes built-in 24-bit DSP for room and speaker tuning.

Ideal For

• Conference rooms and meeting spaces.
• Corporate offices and commercial buildings.
• Schools, colleges, and universities.
• Hotels, restaurants, and hospitality venues.
• Retail stores and shopping centers.
• Houses of worship and religious facilities.
• Government buildings and public facilities.
• Professionally installed audio systems.

What's in the Box

• Crown Audio CTD-4125 4-Channel 125W per Channel Power Amplifier (1/2-Rack)
• Power Cord
• 4 x 3-Pin Input Block Connector
• 2 x 4-Pin Output Block Connector
• 6-Pin GPI Connector
• 3-Pin Fault Relay Block Connector
• Rackmount Hardware
• 4 x Rubber Feet

Inputs & Outputs

• 4 × 3-pin block analog audio inputs.
• 2 × 4-pin block speaker outputs.
• 2 × RJ45 Dante/AES67 network audio ports.
• 1 × 6-pin block GPIO input.
• 1 × 3-pin block fault logic input.
• 1 × IEC AC power connector compatible with NEMA 5-15 systems.

Frequently Asked Questions

How much power does the Crown Audio CTD-4125 deliver?

It delivers 125 watts per channel across four channels, with a total of 500 watts available through flexible power sharing.

What speaker systems does the CTD-4125 support?

It supports 4-ohm and 8-ohm low-impedance speakers, along with 70V and 100V high-impedance speaker systems.

Does the CTD-4125 have built-in DSP?

Yes, it features 24-bit DSP operating at 48 kHz for room and speaker tuning, including factory JBL SpeakerTunings for select compatible models.

How can the amplifier be configured and controlled?

It can be configured through a web interface using a computer or tablet. It also supports Dante/AES67 networking, HARMAN HControl, GPIO, and third-party control system integration.

Full Technical Specifications

Audio Performance

Brand	Crown
Model	CTD-4125
Series	ComTech D Series
Product Type	Four-Channel Power Amplifier
Amplifier Class	Class-D
Number of Channels	4
Power Output	4 × 125W with all channels driven equally
Maximum Power Sharing	500W shared across four channels
Supported Load Impedance	4Ω and 8Ω
High-Impedance Support	70V and 100V
Frequency Response	20 Hz–20 kHz (±0.5 dB)
Damping Factor	≥100
Signal-to-Noise Ratio	104 dB analog; 113 dB Dante
THD+N	≤0.1%
Intermodulation Distortion	≤0.35%
Crosstalk	Greater than −90 dB (20 Hz–1 kHz)
Digital Signal Processing	24-bit DSP at 48 kHz
Speaker Tuning	Custom tuning and factory JBL Speaker Tunings for select models
Network Audio	Dante and AES67
Control Protocol	HARMAN HControl
Configuration	Web-based user interface
Monitoring Features	Features: Pilot tone and load monitoring
Additional Features	Power sharing, source priority switching, GPIO, and fault monitoring
Analog Audio Inputs	4 × 3-pin block connectors
Speaker Outputs	2 × 4-pin block connectors
Network Connections	2 × RJ45 Dante/AES67 ports

Connectors

Analog Audio Inputs	4 × 3-pin Phoenix terminal block connectors
Speaker Output	2 × 4-pin Phoenix terminal block connectors
Network Audio	2 × RJ45 Dante/AES67 ports
GPIO Control Input	1 × 6-pin Phoenix terminal block connector
Fault Relay Connector	1 × 3-pin Phoenix terminal block connector
AC Power Connector	1 × IEC power connector

Power & Operation

Power Output	4 × 125W with all channels driven equally.
Total Power	500W with flexible power sharing.
Supported Loads	4Ω and 8Ω low-impedance speakers.
High-Impedance Operation	Supports 70V and 100V speaker systems.
Input Voltage	100–240V AC, 50/60 Hz.
Amplifier Class	Class-D.
Digital Signal Processing	Built-in 24-bit DSP operating at 48 kHz.
Cooling System	Convection cooling for quiet operation.

Dimensions & Weight

Dimensions:	(L × W × H): 14.1"× 8.6"" × 1.75"
Weight	7.1 lbs