D48 Matrix Signal Processor


The D48 is the result of several decades worth of NST Audio R&D experience in designing the very best in professional DSP products. Designed to give superlative audio performance, the D48 works in both live production and installations to get the most out of your system.

D48 Overview

With inputs and outputs switchable in channel pairs between analogue or AES/EBU the D48 gives you the flexibility you need to integrate into your system. Compressors are available on every input as well as a high pass filter, 6 bands of parametric EQ and up to 1.3 seconds of delay. Routing to outputs can be configured to either mix-matrix mode, free-routing or several pre-configured routing options. Flexible channel linking enables quick and easy configuration of common crossover setups or customised configurations as required. Every output channel has high and low pass filters, 8 bands of parametric EQ, up to 1.3 seconds of delay as well as a new limiter designed to offer the best driver protection with the lowest distortion.

The D48 runs at 96kHz as standard but can be switched into 48kHz mode to take advantage of 48dB/oct output crossover filters and two bands of dynamic EQ on both input and output channels. Front panel control allows instant mute of any input or output as well as editing of all the most commonly used parameters and recall of presets.

The ethernet based PC control software gives you the ability to not only control all the devices on a network but also to store preset memories and configure systems offline. With Mac and iPad control software due mid-2015, you can control your system the way that suits you.

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D48 Technical Specifications

Analogue Inputs – 4

Electronically balanced, pin 2 hot
CMRR : >60dB @ 1kHz
Maximum Level : >20dBu
Input Impedance : 10kΩ balanced

AES Inputs – 2 x 2 channel

Transformer balanced, pin 2 hot
AES Input Sample Rates : 8kHz to 96kHz
AES Input s/n Ratio : 139dB
Input Impedance : 110Ω

Analogue Outputs – 8

Electronically balanced, pin 2 hot
Maximum Level : >20dBu
Source Impedance : <60Ω

AES Outputs – 4 x 2 channel

Transformer balanced, pin 2 hot
Sample Rate : same as operating sample rate
Source Impedance : 110Ω


Frequency Response (20Hz to 20kHz) : +/-0.4dB
Dynamic Range : >115dB unweighted (in to out analogue)
THD + N (+10dB @ 1kHz) : 0.0013%
Latency : 1.074ms (in to out, analogue, 96kHz)


Input Gain (per channel) : -30 to +15dB in 0.1dB steps, mute, phase
Input Delay (per channel) : 0 to 1.3s in 10.4uS steps (at 96kHz)
Input Compressor (per channel) : Threshold (-30 to +22 dBu), Attack, Release, Ratio, Soft-Knee
Input Parametric EQ (per channel) : 6 bands – parametric, low shelf, high shelf, notch, band-pass
Input High-Pass Filter (per channel) : Up to 24dB/octave (Bensen / Butterworth / Bessel / Linkwitz-Riley)

Routing Inputs to Outputs : Choice of modes (Matrix Mixer, Free Routing, 1×8 crossover, 2×4 crossover, 4×2 crossover, 2×3 crossover + 2 Aux)

Output Parametric EQ (per channel) : 8 bands – parametric, low shelf, high shelf, notch, band-pass
Output Dynamic EQ (per channel) : 2 bands (48kHz only) – parametric/low shelf/high shelf, boost/cut above/below, threshold, ratio, attack, release
Output High-Pass and Low-Pass Filter (per channel) : Up to 48dB/octave (Bensen / Butterworth / Bessel / Linkwitz-Riley) at 48kHz (up to 24dB/octave at 96kHz)
Output Gain (per channel) : -30 to +15dB in 0.1dB steps, mute, phase
Output Delay (per channel) : 0 to 1.3s in 10.4uS steps (at 96kHz)
Output Limiter (per channel) : Threshold (-50 to +22dBu), attack, release, auto attack/release option

Presets : Up to 30


100Mbps Ethernet on rear panel (Ethercon connector)
USB Type B socket

Power Requirements

3-pin IEC input, fused
90-250VAC, 50-60Hz < 40W


Height : 44mm (1.75inch) 1U
Depth : 213mm (8.4 inches)
Width : 482mm (19 inches)


Net : 2.8kg
Shipping : 3.9kg

Due to continuing product improvement the above specifications are subject to change.


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The latest firmware, for NST Audio devices, is included as part of the D-Net software, that can be downloaded from the D-Net page:

   Download D-Net Software