As part of its Opal series, BSS presents a precise, simple tool offering 2 channels of audio gating and 2 channels of compression, parametric and independent, in a single rack unit. The DPR-944 is the model BSS offers for day-to-day work in the studio or live, where we need a reliable but easy-to-use unit and, above all, a highly versatile tool.

Today, professional sound rental companies demand units that are reliable (so they need less maintenance despite the rough treatment they're subjected to), simple (so any engineer can use them) and compact (to save space and weight). That's why in this unit we find a good processor that meets these requirements beyond any doubt.

Versatility is a very important factor to consider when buying new gear, since gigs of very different kinds are constantly taking place, with demands from engineers that force us to set up different controls every time it's needed. Because of this, having a tool that gives us eight gates and eight compressors, completely independent, in just 4 rack units is very attractive.

Before going into a deeper analysis of how this unit performs, let's go over its technical features and the operating possibilities it offers:

Let's start with connectivity
We find that we have an independent input and output for each channel, with balanced XLR connectors, something not all current units have, although at times you might miss the option of using balanced jacks for even more versatility.

The gate
The audio gate section lets us control the sound level during the attack and attenuation time, and offers parametric control (frequency-conscious gating), that is, the ability to precisely select the frequencies that trigger the gate, eliminating false openings. Complementing this frequency selector, there's a button (filter narrow) that applies a band-pass filter around the chosen frequency.

It's important to highlight the listen button, which lets you hear during adjustment not the whole signal spectrum but only the audio output of the parametric filter, which will help a lot when it comes to getting a more precise setting. Visually, there are always two LEDs, open and shut, that show whether the gate is letting the signal through or not.

As in the compressor section, the two gate channels can be linked so that both channels are operated with the controls of the first (very useful for stereo sources, such as a keyboard).

Compression
The compression section uses technology based on VCA attenuators that give us parametric compression, so that only a certain part of the signal's frequency spectrum can be compressed. For this we have a selector for the center point of the chosen range and a bandwidth selector to make the compression more precise. As with the gates, there's a listen button that allows precise adjustment of the frequency range we want to compress by listening only to that range.

Among the controls, besides the selectors mentioned, we find the usual threshold, ratio and gain controls found on all compressors, along with useful LEDs showing the signal below the threshold and the amount of compression being applied.

TECHNICAL SPECIFICATIONS
Input impedance is 10 kohms, balanced or unbalanced. Output impedance is 50 ohms maximum, balanced or unbalanced. Frequency response is +/- 0.25 dB from 20 Hz to 20 kHz, and the signal-to-noise ratio is -95 dBu from 22 Hz to 22 kHz. THD is under 0.04% for the gate and 0.005 for the compressor, from 20 Hz to 20 kHz, measured at 0 dB.

On test
I ran an exhaustive test of both sections of this unit, comparing it with a higher-end unit such as the DBX 160 (the standard among compressors), the DRAWMER DS-201 (the standard among gates) and a Spanish-made unit with similar features, the Altair CN-220.

Starting with the audio gate section, it has to be said that it operates very precisely, opening only when the selected threshold is crossed, and when the parametric filter is used it adapts very well to the selected range. Opening is quick and smooth, as is the release. Compared with today's range of gates, you might miss active attack and release controls, as on the compressor, which would allow a better setting for some instruments; but we have to remember that this is one of BSS's lower-tier series, the Opal, and besides, the physical space of one rack unit doesn't allow for much more than we already have.

The compressor is a very useful tool for compressing selected frequencies and, as in the other section, it's precise and fast. We don't quite have the dynamic range the 160 gives us, but for average use the quality of this unit is more than enough.
I did notice how well the "progressive knee" compression ratio control works, which BSS offers to achieve a soft knee at low ratios and a hard knee at high ratios.

It has to be acknowledged that BSS, using materials of lower quality and sturdiness than those in its high-end range, has achieved a unit with very good electronic quality at a very attractive price.

There's just one detail I miss compared with some other processors, and that's not being able to put the gate and compressor in series internally; of course, BSS explains that this way you won't accidentally activate something you don't want to use, and that it also allows the circuitry to be independent.

CONCLUSIONS
The DPR-944 is a processor that meets the basic requirements an engineer looks for in an audio gate and a compressor, while allowing precise adjustment of their effect on the signals being processed, always bearing in mind that this is a unit housing 2 gates and 2 compressors, completely independent, in a single rack unit, at a more than competitive price in today's market.