TEST: SPL Dynamxx 9735

 Let's start with the question of the day. Apart from a fully parametric equalizer, which processor component requires the most learning and familiarization time to achieve practical results? That's right, we're talking about the compressor!

I vividly recall how overwhelmed I was at the beginning of my career when it came to correctly handling an ADSR compressor. The time components - Attack, Decay, Sustain, and Release - were a complete mystery to me in their complexity. In my early days, this often led to significant setting errors, punishing the production with massive pumping or the breakthrough of fast transients.

A perfectly adjusted hardware compressor is a powerful tool and indispensable in our over-compressed music landscape. However, when equipped with incorrect time components, it can mutilate a transparent mix into an amputated sound experience, robbing each individual track of its identity and assertiveness.

What could be more logical than providing the ambitious user with a tool that combines the aforementioned ADSR technique into an automatism with practical values, without having to deal with presets as used in the software sector with varying degrees of quality?

SPL has developed such a hardware solution with the DynaMaxx and is setting out to master the complex mechanism with a minimum of adjustment options.

## Construction and Design

The DynaMaxx comes in a 1U rack unit with a depth of 23.7 cm and weighs 3.4 kg. It's the first compressor to work with two THAT 2181 VCAs in parallel, known for their particularly neutral and low-distortion sound.

Visually, the device is housed in an attractive blue-black finish. This stereo unit manages to handle not only the ADSR functions but also a noise gate with just three rotary controls and four push buttons per channel.

The noise gate features an ARS (Auto-Release-Circuit) and is automated like the compressor. It's designed to provide a particularly smooth fade-out. The ARS circuit "remembers" the level jump between the music signal level and the threshold set via the noise gate control.

If the difference is large, a fast release time is set; if it's small, slower release times are used.

Furthermore, the DynaMaxx features a de-compression circuit to invert the compressor's function. This function gives highly compressed sampler sounds, for example, a more dynamic sound image by working back their loudness amplitude.

## Control Panel Layout

The individual controls and push buttons on the control panel are as follows:

1. Compress: This control simultaneously adjusts threshold and ratio, based on a soft-knee characteristic. An LED placed above and to the left of the control provides information about the operation.

2. Gain: This control compensates for the loss of volume that accompanies the compression process.

3. Noise Gate: Adjusts the activation point of the noise gate.

4. Soft Limit: In this function, the DynaMaxx only processes the peak levels. Unlike the compressor function, it doesn't boost quiet signal components.

5. Effect Compression: Deactivates the automation of the release time and sets a very short value of 60 milliseconds.

6. De-Compression: Activates the de-compression circuit.

7. Active: Switches off the DynaMaxx via a relay hard bypass circuit.

8. LED Display: Two 20-segment LED chains provide information about the set compression value and the associated level reduction in 1 dB resolution.

A stereo couple switch is placed in the center, allowing the device to receive the same control voltage in stereo operation or to operate as 2x mono.

On the rear, the DynaMaxx features balanced inputs and outputs in XLR and jack format. Additionally, there's a side chain input implemented as a stereo jack socket, where filtered or triggered signals can be looped in to externally trigger the DynaMaxx.

## Practical Application

In today's audio landscape, compressors must assert themselves in both instrumental recording and sum processing, which is made more difficult by the fact that both output signals have completely different attack and decay phases.

While the usually highly condensed sum signal of a mix particularly demands uniform smoothing of the peak levels and must not suffer in terms of transparency when loudness is added, a sensitive individual recording requires particularly individual attack and release processing to prevent the notorious pumping, which is still the main problem of correct compressor setting.

Indeed, during the first configuration (single instrument / electric bass), I only had to find a tastefully sensible starting point using the Compress control; everything else actually happened as if by magic all by itself.

How often have I needed 10-15 minutes alone to perfectly adjust a compressor to the respective playing style of the artist? All work that can now be done within a minute.

It's quite astonishing how practically the device manages even complex dynamic processes. Even through high volume fluctuations and "undisciplined" playing, the DynaMaxx doesn't get confused and stays dynamically on course. Just quickly find a suitable value for the noise gate, and you're done!

When it comes to sum processing, things are similarly quick. Despite completely different source material, the compressor leaves a very balanced impression and shines with the simplest handling.

Indeed, the VCAs used deliver a highly transparent sound that at no point tonally alienated the source material or provided it with other artifacts. A well-rounded package!

## In-Depth Analysis of DynaMaxx's Features

### Automatic Time Constant Circuit

One of the standout features of the DynaMaxx is its automatic time constant circuit. This innovative technology continuously analyzes the input signal and adjusts the attack and release times accordingly. This results in a more natural and musical compression that adapts to the source material in real-time.

The automatic circuit is particularly beneficial when working with complex material that has varying dynamics throughout. For instance, when compressing a full mix or a drum bus, the DynaMaxx can seamlessly transition between fast attack times for transient-rich sections and slower attack times for sustained passages, all without user intervention.

### Parallel VCA Design

The use of two THAT 2181 VCAs in parallel is a unique approach that contributes significantly to the DynaMaxx's clean and transparent sound. This design allows for more headroom and lower distortion compared to single VCA designs.

The parallel VCA configuration also enables the DynaMaxx to handle a wide range of input levels without introducing unwanted coloration or artifacts. This makes it equally suitable for subtle compression on delicate sources like vocals or acoustic instruments, as well as more aggressive compression on high-energy sources like drums or distorted guitars.

### De-Compression Function

The de-compression function is an intriguing feature that sets the DynaMaxx apart from many other hardware compressors. This function essentially inverts the compressor's action, expanding the dynamic range instead of reducing it.

This can be particularly useful in several scenarios:

1. Restoring dynamics to over-compressed material: In the age of the loudness war, many recordings suffer from excessive compression. The de-compression function can help breathe life back into these recordings by expanding their dynamic range.

2. Creating space in a dense mix: By selectively expanding certain elements in a mix, you can create more separation and depth, allowing each instrument to occupy its own space more clearly.

3. Creative sound design: The de-compression function can be used to create unique envelope effects, particularly on percussive sounds or synthesizers.

### Soft Limiting

The soft limiting function of the DynaMaxx provides a gentle way to tame peaks without affecting the overall dynamics of the signal. This is achieved through a gradually increasing ratio as the input signal approaches the threshold, rather than a hard knee that abruptly applies full compression.

This soft limiting can be particularly useful in mastering situations or when processing the main mix bus. It allows for increased perceived loudness without the harshness often associated with hard limiting.

## Performance in Various Scenarios

### Vocal Processing

When used on vocals, the DynaMaxx shines in its ability to maintain consistency without robbing the performance of its natural dynamics. The automatic time constant circuit proves particularly useful here, adapting to the varying intensities of a vocal performance without requiring constant tweaking.

The soft knee characteristic of the compression curve allows for a smooth transition into compression, which is ideal for vocals as it helps maintain a natural sound even when applying significant gain reduction.

### Drum Bus Processing

On a drum bus, the DynaMaxx demonstrates its versatility. The fast attack times available allow for transient shaping, tightening up the impact of kicks and snares. Meanwhile, the automatic release times prevent pumping artifacts that can often occur when compressing complex drum patterns.

The parallel VCA design comes into its own here, maintaining the clarity and punch of the drums even under heavy compression. The soft limiting function can be particularly useful for taming occasional peaks without squashing the overall drum dynamics.

### Bass Guitar

Bass guitar is notoriously difficult to compress due to its wide dynamic range and the importance of maintaining both low-end weight and upper-mid definition. The DynaMaxx handles this challenge admirably, thanks to its clean VCA design and intelligent auto-release function.

The compression maintains the body of the bass notes while evening out the performance, and the de-compression function can be creatively employed to enhance the attack of plucked notes for added definition in a mix.

### Mix Bus Application

When used across a full mix, the DynaMaxx proves to be a powerful yet subtle tool for adding cohesion and enhancing the overall energy of a track. The automatic time constant circuit really proves its worth here, handling the complex dynamics of a full mix with ease.

The soft limiting function is particularly useful in this context, allowing for a final stage of peak control without introducing obvious compression artifacts. This can help achieve commercial loudness levels while maintaining the mix's dynamic integrity.

## Comparison with Software Emulations

While software plugin emulations of classic compressors have come a long way in recent years, the DynaMaxx offers several advantages over its digital counterparts:

1. Zero latency: As a hardware unit, the DynaMaxx processes audio in real-time without introducing any latency. This is particularly beneficial in live sound applications or when tracking.

2. Analog warmth: Despite its clean and transparent design, the DynaMaxx imparts a subtle analog character to the signal that many find pleasing. This is often described as adding "glue" to a mix.

3. Tactile control: The physical knobs and buttons of the DynaMaxx offer a level of intuitive control that's hard to replicate with a mouse and screen. This can lead to faster, more musical decisions during mixing.

4. Reliability: Hardware units like the DynaMaxx are not subject to software crashes, compatibility issues, or the need for constant updates.

## Integration into Modern Workflows

Despite being a hardware unit, the DynaMaxx integrates seamlessly into modern, hybrid mixing setups. Its balanced XLR and TRS connections allow for easy integration with professional audio interfaces.

For those working primarily "in the box," the DynaMaxx can be used as an outboard processor via the aux sends of a DAW. This allows for the best of both worlds - the flexibility of digital mixing combined with the sound quality and hands-on control of high-end analog hardware.

The side-chain input also opens up creative possibilities when integrated with a DAW. For instance, you could send a filtered version of a kick drum to the side-chain input to create ducking effects on a bass track, all while benefiting from the DynaMaxx's superior analog processing.

## Conclusion

The SPL DynaMaxx proves to be a true dynamic all-purpose weapon. It provides excellent service, especially when the interested user still lacks the necessary experience or knowledge in the difficult-to-penetrate ADSR jungle, or when things need to move very quickly, for example in the live sector.

Never before have I managed to add loudness gain to even dynamically highly complex material in such a short time. All controls are practically self-explanatory and require no extensive familiarization time.

Due to its sophisticated components and very good coordination with each other, one would have to go to great lengths to coax a dynamically unbalanced sound out of the Model 9735. I certainly didn't succeed during the test operation.

The handling is very clear and easy to learn even for the inexperienced user, so that after completing "dynamic" basic training, one can gradually dare to tackle manual time component management.

A high-quality product with very high practical value! Highly recommended.