miniDSP Flex 2 In / 4 Out Audio Processor

Introducing the miniDSP Flex 2 In / 4 Out Audio Processor

The miniDSP Flex 2 In / 4 Out audio processor is a compact digital signal processor (DSP) platform designed for subwoofer integration, active crossovers and system optimisation in stereo systems. It is available in three versions: Flex RCA, Flex Balanced and Flex Digital. Each version uses the same DSP processing platform and software, but offers different analogue or digital connectivity to suit different systems.

What the Flex does

Flex gives you precise control over how your speakers and subwoofers behave in your room. You can implement crossovers, adjust levels, apply parametric EQ, add delay for time alignment and route signals flexibly using the built-in matrix mixer. This makes the Flex suitable for straightforward two-channel systems with a subwoofer, as well as more ambitious active crossover setups.

Digital connectivity

All versions of the miniDSP Flex include USB, coaxial, optical and Bluetooth digital inputs. The USB interface also supports bi-directional audio, allowing audio to be sent from the Flex back to a macOS or Windows computer. This can be used for recording and archiving audio, and it can also be useful during system setup when working with measurement and analysis software.

Three versions: RCA, Balanced and Digital

Flex is available in three versions. They share the same DSP capabilities and digital inputs, but differ in their analogue and output options.

Flex RCA

Flex RCA is designed for conventional hi-fi systems using standard RCA connections. It provides two analogue RCA inputs and four analogue RCA outputs, making it a natural fit for systems where you want to integrate one or more subwoofers, implement an active crossover, or apply DSP-based optimisation while keeping the rest of the system simple and familiar.

Flex Balanced

Flex Balanced uses balanced TRS inputs and outputs. Balanced connections offer improved noise rejection and are particularly useful with balanced DACs, studio equipment, active monitors, or longer cable runs where signal integrity matters. If the rest of your system is built around balanced interconnects, Flex Balanced is usually the most straightforward choice.

Flex Digital

Flex Digital is designed for systems that already include an external DAC. It provides analogue inputs but uses digital outputs, allowing the Flex to perform DSP processing while leaving digital-to-analogue conversion to a separate component. This is a good option if you want the flexibility of the Flex platform but prefer the sonic character or connectivity of your own DAC.

Need more than four output channels?

If you need more than four output channels, and you can manage without analogue inputs, have a look at the Flex Eight 2 in / 8 out model. This is our go-to option for multi-sub optimisation using three or more subwoofers.

Need more analogue inputs or a phono stage?

If you need more analogue inputs, consider pairing your Flex processor with the miniDSP ADept analogue-to-digital converter. It offers RCA and XLR inputs, and connects to your Flex via optical or coaxial. ADept also has a built-in MM/MC phono stage, providing a clean and simple option for connecting a turntable.

Dirac Live room correction (optional)

Dirac Live room correction is available as an optional upgrade for the miniDSP Flex platform. Dirac analyses how your speakers interact with your room and creates correction filters that address both frequency response and timing, helping to reduce unwanted colouration, tighten bass and improve clarity and imaging.

Dirac Live can be added at the time of purchase or activated later via a software licence through the miniDSP Device Console companion software. Once licensed, you measure your system using a calibrated microphone, generate correction filters, and load them into the Flex.

KD-1 controller (optional)

miniDSP offers the KD-1 smart remote control as an optional hardware controller for the Flex platform. It provides convenient day-to-day control of volume, input selection, preset selection and Dirac on/off, with clear visual feedback via its built-in display, without needing to use the front panel controls or IR remote. KD-1 is compatible with Flex 2 in / 4 out models, Flex Eight and all SHD models.

Key features

• High-precision DSP engine with 32-bit floating-point processing
• 2 input / 4 output architecture for sub integration and active crossover setups
• Matrix mixer for flexible routing and summing options
• Parametric EQ, crossover filters, delay and time alignment
• USB, coaxial, optical and Bluetooth digital inputs
• Optional Dirac Live room correction support
• Compact chassis and straightforward configuration software

Measurement microphones

If you are planning to use Flex for room correction or subwoofer integration, accurate acoustic measurements are essential. You will need a measurement microphone, a Mac or PC, and measurement software such as Dirac Live or Room EQ Wizard.

For most measurement tasks we recommend the miniDSP UMIK-1. It is simple to use, widely supported and is an excellent match for typical Dirac Live and REW workflows.

We also stock the premium miniDSP UMIK-2 microphone. This model has a larger capsule and a high performance analogue-to-digital converter, which give it greater sensitivity, higher dynamic range, a wider frequency range, and lower self-noise, for even more precise measurements.

Frequently asked questions