8-channel balanced home theater processor with Dolby Atmos and DTS:X decoding

The miniDSP Flex HTx+ is a 1U rackmount multichannel DSP processor designed for home theater, multichannel audio and advanced audio processing applications. The big brother of the Flex HT+, it combines an onboard Dolby Atmos and DTS:X decoder, the miniDSP toolbox, and 8 analog inputs and 8 analog outputs available in both balanced and unbalanced form.

Built-in Dolby Atmos and DTS:X decoding, HDMI eARC connection

This is the key upgrade over the Flex HTx: the Flex HTx+ decodes Dolby Atmos, Dolby Digital Plus, DTS:X and DTS streams on its own. Decoding works from the HDMI input, the coaxial SPDIF input and the Toslink optical input. With the Flex HTx, the source had to output PCM; here, the processor handles the soundtrack as it comes in.

The HDMI eARC/ARC port lets you connect the processor straight to your TV and get its audio over a single cable.

8 analog inputs and outputs, on RCA or balanced jack

Each of the 8 input channels and 8 output channels is available both on unbalanced RCA and on balanced 6.35 mm (1/4") TRS jack. The Flex HTx+ connects just as easily to hi-fi amplifiers as to active speakers or professional amps, and its 1U format with the supplied removable rack ears makes it at home in a studio rack or an equipment cabinet.

On the digital side, you get stereo coaxial and optical SPDIF inputs, plus multichannel USB Audio up to 7.1: connected to a computer, the Flex HTx+ works as an 8-channel USB DAC, driven by a multicore XMOS USB processor.

Full DSP processing, with Dirac Live as an option

At the heart of the processor is an Analog Devices SHARC 400 MHz DSP running 32-bit floating point. The miniDSP toolbox gives you routing, bass management, parametric EQ, active crossovers, advanced biquads, delay and gain. Everything you need to integrate subwoofers properly or run multi-way speakers actively.

The Flex HTx+ supports multichannel Dirac Live 3.x, on 8 channels and full range from 20 Hz to 20 kHz. This is an optional, paid software upgrade that is not included with the unit. Dirac ART and Dirac Live Bass Control are not available on this model: for those features, miniDSP recommends the miniDSP Tide16. To measure your room with Dirac Live, you need a measurement microphone (UMIK-1 or UMIK-2), not included, such as the miniDSP UMIK-1.

Who it is for, and how it compares with the Flex HT+ and Tide16

The Flex HTx+ is for anyone who wants a compact rackmount home theater processor that decodes immersive formats on its own, while keeping the flexibility of a miniDSP DSP and balanced connections. It sits above the Flex HT+ in the range. If your system calls for Dirac ART or Dirac Live Bass Control, though, the Tide16 is the one to look at.

In daily use, the front-panel OLED display, volume knob and infrared remote keep things simple. Setup is done with the miniDSP Device Console software, and software and firmware updates are free.

Available to order: miniDSP expects first shipments at the end of November 2026.

Specifications

• 1U rackmount multichannel processor, removable rack ears included
• 8 analog inputs on unbalanced RCA and balanced 6.35 mm TRS jack
• 8 analog outputs on unbalanced RCA and balanced 6.35 mm TRS jack
• Dolby Atmos, Dolby Digital Plus, DTS:X and DTS decoding from HDMI, coaxial SPDIF and Toslink
• HDMI eARC/ARC
• Stereo coaxial and optical SPDIF digital inputs
• Multichannel USB Audio up to 7.1, 8-channel USB DAC, multicore XMOS USB processor
• Analog Devices SHARC 400 MHz DSP, 32-bit floating point
• Routing, bass management, parametric EQ, crossovers, advanced biquads, delay and gain
• Multichannel Dirac Live 3.x (8 channels, 20 Hz to 20 kHz) as an optional paid upgrade, not included
• Dirac ART and Dirac Live Bass Control not available on this model
• SNR: 127 dB(A)
• THD+N: -120 dB (0.0001%)
• Front-panel OLED display, volume knob, infrared remote
• Setup via miniDSP Device Console, free software and firmware updates
• In the box: Flex HTx+, IR remote, 12 V universal power supply, USB cable, removable 1U rack ears
• Not included: measurement microphone (UMIK-1 or UMIK-2) required for Dirac Live, TRS to XLR cables