DSP-8C vs miniDSP Flex Eight

The CoLinear Acoustics DSP-8C and the miniDSP Flex Eight are both two-in, eight-out digital signal processors aimed at active loudspeaker and subwoofer systems. They occupy similar territory on paper, so this page sets out how they compare on the specifications that matter for active crossover and correction work. All figures are taken from each manufacturer's own published specifications: the DSP-8C's from its product page, and the Flex Eight's from miniDSP's Flex Eight product brief, accessed 30 August 2026.

Specification comparison

Specification	CoLinear DSP-8C	miniDSP Flex Eight
Input / output channels	2 / 8	2 / 8
THD+N (digital to analogue)	up to −126 dB / 0.00005% (unweighted)	−111 dB / 0.0003%
Dynamic range / SNR	130 dB(A)	125 dB(A), with DRE enabled
Processor	1 GHz SHARC+ with FIR/IIR accelerators	400 MHz SHARC (ADSP-21489)
Processing resolution	32-bit floating point, 40-bit on the input filters / up to 192 kHz	32-bit floating point / 96 kHz (48 kHz with Dirac Live)
Analogue outputs	8 x RCA and 8 x XLR, selectable per channel	8 x RCA
Output level	2.0–2.5 V RMS SE / 4.0–5.0 V RMS balanced, adjustable	2 V RMS
Output impedance	95 Ω SE / 190 Ω balanced	200 Ω
FIR filtering	Every channel, input and output: 16,384 input + 30,336 output taps at 96 kHz, 9,216 + 15,104 at 192 kHz	Stereo bank on inputs only (2 x 2048 taps @ 96 kHz)
IIR filtering	348 biquads: 60 across the two inputs, 288 across the eight outputs	10 parametric EQ bands per channel, 100 in total, programmable as raw biquads
Frequency response	20 Hz–20 kHz, +0.0 / −0.02 dB	20 Hz–20 kHz, ±0.05 dB
DAC	ESS ES9039SPRO, HyperStream IV	Not published
Digital inputs	USB, S/PDIF coaxial, optical	USB, S/PDIF coaxial, optical, Bluetooth
Digital outputs	S/PDIF coaxial, optical	None; the Flex Eight-N variant offers digital output over Ethernet
Room correction	Manual, typically using LinFIR or REW/rePhase workflows	Dirac Live (paid upgrade)
Front panel	OLED display with encoder	OLED display with encoder
Presets	4 profiles	4 presets
Control software	DSPconfig (Windows / macOS / Linux)	Device Console (Windows / macOS)

Performance

The clearest separation is in analogue performance. The DSP-8C specifies THD+N of up to −126 dB (0.00005%) unweighted and a dynamic range of 130 dB A-weighted, against the Flex Eight's −111 dB (0.0003%) and 125 dB(A). Much of this comes down to the converter and output stage: the DSP-8C uses the ES9039SPRO with a meticulously optimised OPA1612-based analogue output stage.

Both run on Analog Devices SHARC processors, but the DSP-8C's 1 GHz SHARC+ runs at more than twice the clock of the Flex Eight's 400 MHz part, and adds dedicated FIR and IIR accelerators. That headroom is what allows the DSP-8C to process at up to 192 kHz and to offer considerably more FIR filtering on every channel rather than only a stereo bank on the inputs.

Processing architecture

For active crossover work the FIR arrangement is the practical differentiator. The Flex Eight provides a stereo FIR bank on its two inputs (2 x 2048 taps at 96 kHz), which is well suited to input-side correction or a linear-phase front end. The DSP-8C makes FIR available on every input and output channel, so per-driver FIR correction, including the IIR-plus-FIR phase linearisation described in our FIR vs IIR article, can be applied independently to each output.

The DSP-8C also processes at up to 192 kHz, where the Flex Eight runs at 96 kHz, dropping to 48 kHz when the Dirac Live licence is active. For a system relying on high-resolution FIR correction, the available sample rate and tap budget directly affect how precisely filters can be defined.

Furthermore, where possible, we make use of the SHARC+ architecture's native 40-bit-wide registers, which results in a lower noise floor when processing input channel biquads and FIR filters than standard 32-bit resolution.

Connectivity and integration

The output stage is the other significant difference. The DSP-8C provides both single-ended RCA and true balanced XLR on every channel, selectable per output, with a calibrated output level adjustable from 2.0–2.5 V RMS single-ended or 4.0–5.0 V RMS balanced. This makes it straightforward to match a wide range of power amplifiers and active speakers, including balanced studio and professional equipment. The Flex Eight provides eight unbalanced RCA outputs at a fixed 2 V RMS.

The Flex Eight does offer Bluetooth input, which the DSP-8C does not, and an optional Dirac Live licence for automated room correction.

We deliberately exclude Bluetooth connectivity for two reasons. Firstly, every codec it accepts is lossy: LDAC carries 24-bit 96 kHz material at up to 990 kbps and aptX HD carries 24-bit 48 kHz at 576 kbps, where that same 24-bit 96 kHz stereo stream is 4.6 Mbps uncompressed. Secondly, siting a Bluetooth/wireless transmitter in the same enclosure can significantly degrade the performance of the analogue output stage. We typically expect users either to play audio over USB Audio 2.0 from a computer, or to connect an external streamer to the DSP-8C over S/PDIF.

For room correction, the DSP-8C targets a measurement-led workflow using tools such as REW and rePhase, giving direct control over crossover, FIR and phase design through DSPconfig.

Summary

Both processors cover the same basic format and both are capable platforms for active speaker systems. The miniDSP Flex Eight adds Bluetooth and an optional Dirac Live room-correction licence, and is a compact, well-established option.

The DSP-8C is built around higher analogue performance and greater processing capability: lower noise and distortion, a faster processor, processing to 192 kHz, FIR on every channel, and selectable balanced or single-ended outputs with adjustable level. For systems where measured performance and per-channel FIR correction are the priority, those differences are the deciding factors. Our tightly integrated control software is designed from the ground up to make room and driver correction as straightforward as possible.