A compressor of its own kind!

by Mario Laemmerhirt
delamar (Germany) – January 2010

Well, another analog compressor which has been transferred into the digital domain. Don't we already have enough plug-in emulations of analog hardware? Maybe, but the functionality of the mpressor is based on a special concept – building the bridge between standard tasks in mixing or recording and creative sound shaping with spectacular dynamic results.

Actually, elysia is known for their high end analog studio equipment, but from now on, the mpressor is not only available for studio owners who are able to raise the cash for the hardware, but also as a much more affordable software plugin. It is also interesting that the software company Brainworx is responsible for the true-to-original translation of the hardware into the digital realm – a company which has an equally good reputation in their profession as elysia have in theirs. Under these circumstances, we can expect the mpressor to be a true high end plug-in.

elysia announces the mpressor as a "creative compressor" with character as well as a universal tool for any compression application. The following features are essential parts of the special design: the Gain Reduction Limiter for remaining dynamics on strong gain reduction processes, the Niveau Filter which can shift the sound into darker or brighter directions, negative ratios for pumping grooves, the Anti Log function for a non-linear progress of the release curve and Auto Fast as a semi-automation for shortening the attack time. No doubt, these are valuable conditions for surviving in the highly competitive plug-in market. The mere functionality of the mpressor alone is a big bonus, especially as many companies offer character emulations of the same classics (just think about one of the most usual suspects, the 1176 LN).

The details
At the moment, the mpressor is available in its 1.0.2 release in VST, RTAS, AU and TDM, but it requires an iLok dongle for the authorization. The installation of the plug-in worked without any problems as expected. iLok owners can test the elysia mpressor for 14 days, by the way.

Fortunately, the mpressor is sidechain-enabled and also available in the VST3 format. It's really worth pointing this out, as other companies with bigger names play catch-up in implementing this ‘new’ VST3 standard. The system requirements for Mac and PC keep within reasonable limits (they can be found on the manufacturer's web site).

Graphical user interface
The GUI of the elysia mpressor has been adapted from the hardware. The clean and tidy layout looks very classy also in its software version. A little eye-catcher, if you ask me. The GUI is well-structured and there is no need for much practice to get started.

Mouse wheel control
The mpressor can be controlled by the mouse wheel, which turns out to be very comfortable in use. Alt + mouse wheel switches to linear mode and Shift + mouse wheel switches to fine tuning mode. There is no need to keep the mouse button pressed for editing parameters any more.

Sidechain functionality
Thanks to the external sidechain input, the mpressor can be used for groove-triggered and frequency-dependent compression.

Oversampling
The mpressor uses oversampling for its internal signal processing for the sake of sound quality. Because of the higher resolution, the compression process can be calculated more accurately. The mpressor uses 4x oversampling on project sample rates below 50 kHz and 2x oversampling on project sample rates below 100 kHz. This needs more CPU power, but it won't hurt a modern system too much.

Link button
In link mode, the mpressor operates as a true stereo compressor. Both channels, left and right, are processed by one combined control voltage, while every channel has a control voltage of its own in unlinked mode.

Auto Fast
During my tests for this review I noticed how fast the mpressor can 'grab'. It offers attack times from 0.01 ms to 150 ms. It is a well-known fact that extremely short attack times can cause audible artifacts when very dynamic material is processed. This is where the Auto Fast function comes in handy: With it, you can easily set a longer attack time, because the mpressor will now automatically shorten this parameter on fast dynamic impulses in order to prevent the transients from slipping through. After this process the attack time returns to its original value. This function is very useful for subgroups where the demands on dynamic processing can be quite diverse throughout a track. The elysia mpressor only hits hard when becomes necessary, without generating audible distortion at higher gain reduction values.

Anti Log
With its non linear release curve in Anti Log mode, the mpressor can be used to create beautiful compression effects. In this mode the release parameter remains at a higher value for a longer time after which it rises quickly. This causes the compressor to pump and groove, which is an especially interesting and vivid compression characteristic for producers of electronic music. The range of release values lies between 5 ms and 1.2 seconds.

Negative ratios
A negative ratio turns the functional principle of a compressor upside down. Weak signals are not raised in level by the compression process, but it is just the other way round: Loud signals are decreased in level by the compressor. With this option the mpressor offers a wonderful pool of sound effects. Especially in combination with the Anti Log function the mpressor can transform a signal to an extend which even makes slapback effects possible.

Gain Reduction Limiter
The Gain Reduction Limiter of the mpressor is not working in the audio path of the compressor as expected, but it limits the ‘control voltage’ of the plugin instead. This means that signals which extend the setting of the GR Limit controller in terms of gain reduction will not be compressed any further. This is especially useful for ducking effects, because the overall dynamics of the processed dynamics remains intact.

Niveau Filter
This filter is not a shelving or parametric EQ, but it cuts and boosts around its selectable center frequency at the same time. The Niveau Filter works like scales or a swing around its center in order to add more character. The result is an overall brighter or darker overall sound.

If the frequency area below 80 Hz is cut, for example, the swing effect will boost the frequencies above 80 Hz at the same time. The EQ Gain controller has a cut and boost range of 6 dB in both directions, and the frequency range can be shifted times ten with the corresponding x10 button, resulting in a filter frequency range from 26 Hz to 22 kHz. The section can also be used as a high cut or low cut filter by turning the Gain controller into its extreme left or right position.

Sound Samples
• Drums 1 clean
• Big Drums
• With negative ratio, Anti Log & Auto Fast
• Percussion 1 clean
• GR Limiter, Auto Fast & Niveau Filter
• Drums 2 clean
• Reverse effect without EQ filter
• Reverse effect with EQ filter
• Reverse effect triggered via sidechain

Overview
Pro
+ Outstanding sound quality
+ Diverse compression effects 
+ Fun factor
+ All-purpose approach

Con
- Price too high for beginners
- Needs iLok (additional costs)

Result
I have to admit that I was really curious how the mpressor would present itself during this test, as I have always been a friend of strong compression: shaping the source signal with a new envelope, adding a new color and a character of its own. Creative processing of audio signals, using a compressor almost as an instrument and still being able to master all sorts of ‘everyday compression’ – only very few software compressors can manage this balancing act.

One of the compressors which falls into this category is the AM Track which is part of the AM Suite by Magix. But with the elysia mpressor it sounds even better. If you ask me, elysia have kept their promise all along the line. I, for one, could not find a fly in the ointment. The mpressor cuts an extremely fine figure when used as a creative sound shaping tool. I experienced its interesting compression effects to be very convincing. I would even go that far to declare the mpressor as my new reference class. It handles everyday compression easily and it is a rich source for joyful experiments – all in one!

It is very obvious that Ruben Tilgner has put a lot of thinking into new approaches, and that he was  able to put them into practice, too. Maybe that’s no big surprise, as he was the one to develop the Transient Designer for SPL. I am positive about this young company elysia from beautiful Nettetal giving us more joy in the future. Anyway, the mpressor proves to be a great start into the digital realm.