Review of SpecOps spectral effects plugin by Unfiltered Audio

Unfiltered Audio have announced the release of SpecOps, a complex, powerful, easy-and-fun-to-use plugin possessing 36 diverse and flexible spectral effects, ranging from subtle to extreme, so sound designers and electronic music producers can easily access a multiverse playground of special effects and sweeteners that can deconstruct sounds at the spectral level and reconstruct them in new and exciting ways.

SpecOps is available for purchase — as AAX AudioSuite-, AAX Native-, AU-, VST2-, and VST3-supporting plugin formats for Mac OS X (10.8 through 10.12), Windows (7 through 10), and Pro Tools 10.3.10 (or higher) — exclusively from Plugin Alliance at an introductory promo price of $89.00 USD until October 20, 2017, rising to an MSRP of $129.00 USD thereafter.

Fully-functional, 14-day trials are available to anyone registering for a free Plugin Alliance account here

Note that the proprietary Plugin Alliance Installation Manager means users can select, download, and install only the products and formats needed for their system.

For more in-depth information, including several superb-sounding audio demos, please visit the dedicated SpecOps webpage here

Watch Plugin Alliance’s tantalizing trailer for SpecOps here

Watch Urban Sound Studio’s Todd Urban’s SpecOpstutorial here


This is an awesome and very cool effect. It’s one of those that is quite difficult to explain how it works but in some ways that doesn’t matter because it’s so much fun experimenting to see what happens. It comes with a lot of presets which are ready to use and highlight the enormous potential of SpecOps or if you take the fully experimental approach and start from scratch it won’t be long before you see results because it’s very easy to start using. You can spend countless hours playing around with SpecOps, it’s incredibly flexible and versatile and can be used as an insert effect, for mixing, mastering or sound design. It can do subtle things like add warmth to thin guitar tracks, fatten up weak frequencies in the bottom end or add subtle movement to pad or synth sounds. It’s equally at home destroying basslines with a bitcrusher / distortion type of effect, adding glitchy polyrhythms to drum tracks or mangling them completely. You can also use the ‘freeze’ function to create a spectral synthesizer and it also has very powerful modulation options.

I’ve created an album using SpecOps which is embedded above. I’ve used Polygon (Glitchmachines); Predator 2, Punch, RP Verb 2, RP Delay (Rob Papen); Synthmaster 2.8 (KV331 Audio) and have used SpecOps as an insert effect on every track. The album was recorded live in Sensomusic Usine Hollyhock 3 and some of the live edits did produce a few unexpected glitches for instance when I used the freeze function of the drums the timing wasn’t always spot on when unfreezing but I’m really pleased with the overall result. I subsequently mastered the tracks in MuLab 7 using bx_console E (Brainworx) or Neutron (iZotope) and Stage (Fiedler Audio)

In-depth review

The GUI has a very modern, clean and minimal look to it. There is the option of a black or white background and a number of different zoom settings. It’s important to remember that this is a frequency based effect rather than a time based effect and the best way to explain this is to use the signal flow which is shown below:

signal flow.jpg

The effect is rather complex but essentially uses FFT (Fast Fourier Transform) which basically uses maths to split a complex signal into its component frequencies which in SpecOps are called ‘bins’. These bins can then have their speed adjusted and ‘geometry’ edited which allows for pitch shifting, stretch and slide. You can select 3 effects from 36 in total which are processed in series. These are followed by the spectral compressor / expander which is the heart of the plugin. Following processing you can adjust the output gain, use a low pass filter to attenuate harsh frequencies and set the amount of wet / dry mix.


The analysis section is the starting point. The FFT size determines how many bins the signal is split into. Low FFT settings such as 128 give a grainy, lo-fi sound whereas high FFT settings such as 32,768 give a higher fidelity sound but introduce latency. Note that high FFT settings are also likely to result in CPU spikes because the interval between applying effects at a higher setting is longer but more effects are applied. At lower settings there is less of an interval between applying effects but SpecOps is using less processor power so CPU usage is more constant. Overall the average usage is about the same but the range will vary considerably based on the FFT size.

The window setting determines how the sound is analysed. There are 7 settings each of which provide different results.

This section also has the input gain control.


The speed control acts differently to how you might expect, it creates feedback between analysis frames decreasing the rate at which new frames are acquired.

Freeze locks the current frame and prevents further analysis. It’s the same as turning the speed control to zero which effectively creates an oscillator using the last group of samples. You can then adjust the pitch shift control to create a spectral synthesizer.


The geometry section has a big impact on the sound. The controls in this section comprise of pitch shift that is quantized from -12 to +12 semitones; slide which is an inharmonic frequency shift and stretch which applies compression or expansion to the bins. It’s like pitch shift but isn’t quantized or phase aware.


The effects section comprises of 3 selectable effects from a total of 36 processed in series from top to bottom. ‘Start’ is the starting frequency the effect is applied at, width controls how many frequency bins are affected and there’s an amount setting for each effect.

The 36 effects comprise a number of filters (low pass, high pass, noise filters); mixing (affect the amplitude); geometry (similar to geometry section but can be applied to specific frequencies); Freezers (similar to the freeze control in the speed section with a number of variants); Effects (contains reverser, glitchers, clippers, smearing); Glitchers (a number of glitchy effects)

spectral compander.jpg

The spectral compander applies to every single bin so with an FFT size of 1,024 there are 1,024 separate companders running simultaneously and at the maximum FFT setting of 32,768 there are 32,768 separate companders running simultaneously. The threshold sets the decibel level at which each compander becomes active; Ratio sets whether bins are expanded or compressed when the bin’s amplitude exceeds the threshold; Knee changes the gain curve transitions from linear to non-linear; Attack determines how quickly the compander reaches its target gain level; Decay determines how quickly the compander returns to a neutral gain level; Mask sets the amount of bleed which can introduce artifacts or produce a less severe sound.


The out section has a gain, low pass filter to remove some of the harsh spectral content in the upper frequencies and a mix control.


The modulation options are flexible and powerful. It’s a modular system and the connectors are arranged so that outputs are at the top of the modulators and everything else is an input, shown by a white circle which have scaling settings. You simply drag from an output to an input and the cable will snap into place. It’s so flexible that the modulators can be used to modulate their own parameters which can create some interesting and unusual results. At present a maximum of 6 modulators can be used at once.

There are six different types of modulators – LFOs (sine/saw/tri/square); input follower; macro control; sample and hold; step sequencer and ROLI lightpad.

The modulation system provides 16 automation slots that can be assigned to one or more modulators and every knob and button on a modulator can be assigned to a slot.

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