Review – CrX4 by LinPlug


We look at LinPlug’s CrX4 is a powerful synthesizer/sample-player, which is a major redesign of LinPlug’s previous product called CronoX3, that has many ways to manipulate your sounds.


by Rob Mitchell, Mar. 2015


LinPlug is a German software company that has many great products in their lineup. Some of their titles include Octopus, Alpha3, and Spectral. For this review, I will be covering their synthesizer/sample-player called CrX4. It is a major redesign of LinPlug’s previous product called CronoX3.

Among its many features are the four generator modules which have five different types of audio generation, two multi-mode stereo filters, multiple LFOs and envelopes, 12 effects, a modulation matrix, and much more.

The system requirements for CrX4 are a PC or Mac with a 1.5 GHz CPU, at least 2 gigabytes of RAM, and 2 gigabytes of free hard drive space. For the PC, you’ll need XP or a later operating system, and for the Mac, you’ll need OSX 10.6 or a later operating system.

The installation was a simple matter on my PC. After you run the installer application, and agree to the license terms, it lets you select either a 32-bit or 64-bit version. You are then able to select a plugin directory to install it to. CrX4 uses a serial number for its copy-protection. After you load it up in the host of your choice, it will prompt you for a serial number.


The Generators

As just mentioned, there are four generators included in CrX4. They are located in the upper left of the display, and two of the four generators are visible at a time. You can switch the view to see the other two generators by clicking the button on the far left, in-between Generator 1 (GEN1) and Generator 2 (GEN2). 

To the right of that control is the Cross-Modulation switch. This lets you change the way to generator’s outputs are combined together. You can select Mix, AM (Amplitude Modulation), or FM (Frequency Modulation). When you set it to Mix, the audio is mixed with the other generators in a regular fashion. If you set it to AM however, GEN1’s output will modulate the amplitude of GEN2. When it is set to FM, GEN1 will then modulate the frequency of GEN2. 

At the top of each generator is an On/Off switch, and a menu to select from the five different generator types. These include Oscillator, Time Sampler, Wavetable, Loop Sampler, and Noise.

The Oscillator generator includes a sawtooth and pulse waveform. Using the waveform control, you can get a sawtooth when it’s turned to the far left, or turn it all the way to the right to get a pulse wave. Anywhere in-between is a blend of the two. The Symmetry knob changes the waveform’s shape, and works with both the pulse and the sawtooth. It can be controlled via the modulation matrix using Aux1 as the target.  I used this for pulse width modulation, and it was easy to setup.

The Spread control is a polyphonic unison adjustment which stacks five generators together, and it increases the amount of detuning as you turn the control. You can also set it to be free running, adjust the oscillator volume, and send the output to either (or both) of the two filters.

CrX4 includes three different sampler modes for the generators: Time Sampler, Wavetable, and Loop Sampler. The Time Sampler can use WAV or AIFF files in formats of up to 24 bit/96 kHz. After loading in a sample, turning up the “Time” control will stretch out the audio over time. It keeps the same pitch, and stretches out the audio, depending on how much that knob is turned from left to right. You’re also able to set the start and end points for playback, set it to loop, and set the Root note value.

Using the Wavetable generator type, you can load in a sample and create a wavetable from it. Changing the “Speed” control varies the playback speed of the wavetable. The “Track” control makes it track the pitch of the notes being played on a keyboard or from your host. For instance, if you play a higher note, it plays back the wavetable faster. If you play a lower note, it would play back at a slower rate.

The Loop Sampler lets you use up to 64 sample slots, and you’re able set a Start point, as well as start/end loop points. It has its own waveform display, which makes it easy to edit the loop points. To open the display, you just click the waveform button right below the name of the sample that is loaded. You’re able to skim through any of the other samples you’ve loaded into the slots by clicking the left and right arrows.

The Smooth control for the Loop Sampler is useful when loop points are used, and helps blend out any undesirable sounds as it loops the sample. Key ranges can be set for each of the samples that are loaded in, and you can set different velocity ranges for each sample.

The Noise generator has both a low pass and a high pass filter built-in. If you use a combination of the two controls in varying degrees, you can then get a band reject or a band pass filter from it. Each filter also has its own “Q” (resonance) control.

You are able to copy and paste the generator settings, and initialize them as well. Tuning is accomplished by using the Semitone and Cent controls, and the Track button enables the pitch tracking. If it is switched to “Fix”, it just uses the Semitone and Cent settings, and plays that same “fixed” pitch no matter what notes are played on a keyboard.


Filters and LFOs

There are two multi-mode filters in CrX4.  Each filter has an on/off button, and a menu to select from three modes of operation. The first mode is “Classic”, and works in a typical manner with cutoff and resonance controls. You can also pick what type of filter it will use: 12dB, 24dB, Band pass, or High pass.

When you switch to one of the other modes, Free 12 dB or Free 24dB, the filter type buttons are replaced with a rotating knob to select the filter type. This can be freely rotated around between the filter types, and can be automated in your host. Another way you might want to use it is to assign an LFO to it (or some other source) in the modulation matrix.

A saturation knob is included for both filters, and can be used to overdrive the sound. The “trk” (Track) control is for key tracking to be used with the filter. The “dep” (Depth) control will alter how much the filter envelope will influence the filter cutoff. Each filter can also be panned left or right, and the two filters can work in serial or parallel modes.


There are four LFOs included, and each of them can be assigned to targets in the modulation matrix. The speed can be dialed in manually, and they can be synced to the host tempo as well. Each LFO also has nine waveforms to choose from.

There are different modes you can use that affect the way the LFO works. You can select these modes by clicking the button above the waveform buttons. The standard setting lets each voice have its own LFO. You can also set it to other modes, such as M (Mono) so all the voices are affected by one LFO. Using R (Retrigger) is similar to the Mono mode, but it will retrigger once a new note is played. The 1 (Single) mode is un-synced and polyphonic. Each voice has its own LFO, but only runs through it for one cycle.

Other controls for customizing the way the LFOs work include Delay, Attack, Phase, and Symmetry. The LFO settings can also be copied, pasted, and initialized.



There are six envelopes available in CrX4. Gen1 and Gen2 each have their own envelope, and the two filters each have one as well. Also, there is an Amp envelope, and a freely assignable Mod envelope which you can set up in the modulation matrix.

All the envelopes work the same way, and each of them can be switched between two different modes. Each of the envelopes can be set to ADSFR or AHDSR modes. The “ADSFR” mode stands for Attack, Decay, Sustain, Fade, and Release. It is a regular ADSR, but the “Fade” that is added in there can make it so the Sustain will either fade in or fade out. The “AHDSR” mode stands for Attack, Hold, Decay, Sustain, and Release. The “Hold” stage basically just adds in a time period between the Attack and Decay stages.


Arpeggiator and Effects


The 32-step Arpeggiator has many settings to change the way it works. If you set it to Mod-Only, it can affect targets in the modulation matrix, but not the notes themselves. The other regular arp playback modes include Up, Down, Up/Down, Up/Down+, Down/Up, and Down/Up+. The “+” after certain modes just means the first and last notes of the chord will be played twice.

The other modes include Random, Chord, and As Played. The “Random” setting will play the notes of a chord in an arbitrary sequence. If you use the “Chord” setting, it plays the actual chord (not as separate notes) and may use other settings to affect the sound. The “As Played” setting will play the notes in the order they were played.

On the right side of the Arpeggiator are some settings you can use to affect the playback of the notes.  You can set it to use up to 32 steps, change the gate time (changes the note length), tempo, octave range, retrigger, and swing amount.

CrX4 has twelve effects included: Delay, Stereo Delay, Ping-Pong Delay, Chorus, Phaser, Filter, Reverb, Flanger, Gator, Stereo Enhancer, Parametric EQ, and Crusher.

Six of the effects can be used at once. The way they set it up is a little confusing at first, but it works fine once you get used to it. There are six effect modules, and modules 1 and 2 can each be setup to use any one of the twelve available effects.

Modules 3 through 6 can be set to have a different effect in each of their modules, but the same effect can’t be used twice. In other words, you can’t have the reverb in module 3, and have the reverb loaded up again in module 4.

To select an effect for a module, you click on the module’s button on the right side, and then click the small arrow at the top of the effects section. You are then presented with a drop-down menu with a list of the 12 effects to choose from.  From there, you just click on one to load it into the module you had selected previously. Each effect has its own On/Off button, and if you switch it on, a small light on the side of the module’s button will light up to indicate it is enabled.



I love the way the interface is designed for CrX4. It’s very easy to use, and nearly everything is on the main screen.  The manual is very good, except I noticed it doesn’t mention the aliasing control in the Oscillator section. It seems to just add a subtle amount aliasing (a distorted type of sound) to the generator’s sound. I’d like it to be more drastic when it’s cranked up because I couldn’t get it to be harsh enough to make a huge difference.

There are a couple of features I’d like to have added in to CrX4. One of those would be to have more slots for the modulation matrix. There are plenty of sources and targets to load into it, but it could be even more flexible with another ten slots available. Also, the effects work well, but I wish there was a way to load/save presets for each of them.

MidiLearn is included, and it can be enabled by clicking the ECS (Easy Controller Setup) button in the lower right. For me, this is always a welcome feature, as it’s much easier than setting it up in my DAW.

Another nice feature I wanted to mention is CrX4’s Chord Memory. This lets you record a chord of your choice (up to eight notes) that can be used with a preset. When you play a note on the keyboard with the Chord Memory switched on, it will play that chord you recorded previously.

CrX4 can make a wide variety of quality sounds, has an abundance of great presets, and the ability to load your own samples further enhances its possibilities. The multi-mode filters work very well. The CPU usage was low, and I didn’t have any issues on my older PC.

Besides my small complaints/suggestions, I can definitely recommend this plugin. It excels as a regular synthesizer plugin, and its palette is expanded in many ways using sample-based material.

CrX4 retails for $149 USD. You can get more info on CrX4 and download a demo version from the LinPlug site here:






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