Eventide Blackhole & MicroPitch Immersive

Eventide’s celebrated reverb and pitch/modulation plug‑ins have been reinvented — with immersive audio applications in mind.

Way back in SOS September 2012, Paul White reviewed the original Eventide Blackhole reverb plug‑in; more recently, in August 2020, he assessed their MicroPitch. Towards the end of last year, Eventide released new versions of both plug‑ins with the multi‑channel capability needed by those working in immersive audio. The plug‑ins come in AAX, AU and VST3 64‑bit formats, for Windows and Mac operating systems. Windows users will need Windows 8 or higher, Mac users OS 10.14 or higher, on either Intel or Silicon machines, and you’ll also need an iLok account. The original stereo‑only versions are still available separately (and more affordably), and if you already own those, Eventide offer a more affordable ‘crossgrade’ option to the immersive versions.

Overview

Both the new plug‑ins are laid out in similar fashion, with the same colour scheme and corresponding controls in the same locations. Those accustomed to the stereo versions will see a lot of familiar controls here, but there are obviously quite a few differences, too — not to mention a bunch of new presets. The multi‑channel output formats supported are LCR, Quadraphonic, 5.0 to 5.1.4, and 7.0 to 7.1.4; following an update in January 2024, mono, stereo and 9.1.6 are now supported too. I was initially unable to get the 7.1.4 option working on Mac/Pro Tools Ultimate 2023.6, but happily the update fixed this. The Immersive plug‑ins will upmix to whichever of those layouts you desire, so you can insert an instance on a mono or stereo channel and route the channel output to a quad bus or 7.1.2 bed, for example.

The plug‑in displays can be resized by dragging from the bottom right corner, and holding down the Command key on Mac or Ctrl key on Windows while changing parameters lets you fine‑tune the settings. Several controls and parameters are common to both plug‑ins too. The input and output level are each adjustable between ‑60 and +12 dB, and along the bottom of each plug‑in are input and output meters, displayed as simple dots, to give you an indication of when signal is present, or if you’re overloading the ins or outs anywhere. Clicking on the mixer icon in this section gives you the option to control the level of the effect going to each output channel. For example, on a 7.1.2 instance you’re given output level control over the front LCR channels, L and R sides, L and R rear, LFE (which also contains a mute option) and L and R top.

The mixer, available in both plug‑ins, allows you to determine how much of the effect output is sent to the different channels in your immersive mix project.

In the centre of each GUI is a very flexible three‑band EQ, with high and low shelves (both switchable to cut filters) and a parametric mid band. This can be used as a general EQ, over the whole effect, but the front, top and rear channels can also be EQ’d independently. Mix is obviously a control that sets the blend of the dry and wet signals. This has a useful lock function, which ensures that your chosen mix blend will remain the same when auditioning different presets. It may seem a simple idea, but it’s so helpful! The Kill Dry button mutes the input signal, and this can be especially useful on the Blackhole reverb plug‑in, as it makes it easier to audition and tweak the reverb sound when you insert this plug‑in on an audio track rather than using it as a send effect. Kill Wet is a momentary button that damps the reverb tail and mutes the effect. Both buttons can be automated, which opens the door to some clever creative effects.

The EQ section on both plug‑ins can operate globally or on individual channels.

Though it’s been renamed Morph, the ribbon control from the stereo version is still here, and operates in exactly the same way. You start by hitting the ‘I’ button on the left of the slider and then set up your sound. Next, hit the ‘II’ button to the right of the slider and adjust some settings. The slider can now be automated to sweep between the two ‘presets’ you’ve just set up. It’s a lovely feature that, I suppose, offers a similar approach to that which an expression pedal might for a guitar effects processor. It makes automating plug‑in settings a lot quicker than tweaking each parameter one by one.

A ribbon controller, now called Morph, blends between two sets of parameters — and can make automation of multiple parameters easier.

All in all, between the EQ and output level controls, there’s all sorts of possibilities available to tailor the effect exactly how you want it in the immersive environment: wetter at the back, drier at the front, brighter at the top... whatever you need.

Blackhole Immersive

Blackhole is a beautiful, luscious, dark‑sounding ambient reverb. The algorithm began its life in the popular Eventide DSP4000 hardware effects unit back in the early ’90s. Owing to its popularity with guitarists, it was released as a dedicated guitar pedal, before also appearing in the Space Guitar and then H9 pedals. But for those of us who are mixing in DAW software, the plug‑in versions are very convenient!

As mentioned previously, those familiar with the stereo plug‑in versions will see a lot of the same parameters here, such as Gravity, Size, and Feedback, which all affect decay time in various ways. Gravity alters the shape of the decay. At the 12 o’clock position, the decay is dense, and it gets smoother as you turn the knob clockwise. Go anticlockwise from the same point and you’re into reverse‑reverb territory. Pulling back the Size parameter can give tight slap‑back‑like effects, and increasing it takes things to canyon‑esque proportions, while Feedback obviously increases the tail of your reverb — but it can do so all the way to infinity if desired.

Crossfeed is a new parameter that doesn’t appear on the stereo version, and this controls how much of the reverb effect is fed into the surround channels. At its minimum setting, the reverb effect appears only on the channels coming into the plug‑in. For example, a 7.1.2 instance of the plug‑in fed from a mono source with Crossfeed at 0% will produce a mono output in the centre channel. Crank the Crossfeed up and the reverb will start feeding all the other channels.

The tempo sync of the stereo Blackhole plug‑in has been treated to an upgrade in the delay section. We can set the pre‑delay here manually from 0 to 2000ms, or can sync the delay to the DAW tempo in beat subdivisions. The loop delay function sets the amount of delay after the reverb function and feeds back into the reverb, creating huge ambient textures.

Handy Tilt controls weight the effect of parameters towards the front or rear of the room.

Another difference between the stereo and immersive versions of both plug‑ins lies in the handy Tilt controls, which weight the effect of parameters towards the front or rear of the room. On Blackhole, these are available for the Gravity, Size and Feedback controls. Basically, you can just set the parameter value to the maximum you want. Tilting the parameter towards the front speakers will then reduce the parameter at the rear, or you can tilt towards the rear of the room to reduce the parameter at the front. Leaving these settings in the centre position will ensure the same values front and rear.

There’s a modulation section to set the depth and speed of modulation in the reverb tail and, finally, the Freeze button. When engaged, this mutes the dry input signal and gives instant infinite reverb. Automate some parameters when freeze is active and you can have all sorts of fun. It’s very cool.

MicroPitch Immersive

What Eventide don’t know about modulation and pitch processing probably isn’t worth knowing, and their processors have long been used to give mono sources such as guitars or vocals a sense of ‘spread’. So it makes perfect sense that these algorithms would find a home in immersive audio productions. But while Blackhole Immersive is, in terms of functionality, broadly similar to the stereo version, the MicroPitch Immersive plug‑in is quite a different beast to its stereo counterpart.

...the MicroPitch Immersive plug‑in is quite a different beast to its stereo counterpart.

Eventide tell us that they “designed MicroPitch Immersive from the ground up for Immersive, Dolby Atmos, and surround workflows. With up to 12 channels of spatialised, detuned delays, plus modulation, EQ, and crossfeed controls, MircoPitch Immersive excels in creating an immersive space with boundaries that reflect, move, diffuse, and dissolve. Whether it be adding a touch of space or creating delayed, pitch diving chaos, MicroPitch Immersive will help you architect both real and unreal immersive realities.”

The main controls for the pitch‑shifting are found in the Detune section. Here, three knobs each look after a pair of parameters, namely Left/Right, Front/Rear and Top/Main. At their default centre positions, no pitch change is applied. Moving the control clockwise on a pair shifts the former parameter’s pitch up and the latter’s pitch down, by between zero and 50 cents. For instance, if we take the Front/Rear control and turn it clockwise, the Front pitch increases and the Rear pitch decreases by the same amount. Moving the control anti‑clockwise decreases the Front pitch and increases the Rear.

Each of the three detune controls also has the Tilt function I discussed above when describing Blackhole. So, again, you can set the pitch‑shift on each of the three controls to the maximum you want, then tilt as desired to offset the value between Left/Right, Front/Rear or Top/Main. The Feedback and Crossfeed controls also operate in the same manner as for the Blackhole plug‑in, and the delay settings are the same too (adjustable manually from 0 to 2000 milliseconds, and can be locked to the DAW tempo). An additional drop‑down menu in this section is the delay pattern option, which makes MicroPitch a very useful multi‑channel delay plug‑in (quite apart from its pitch processing). There are three choices: Self, whereby the delays will appear in their normal position, or Rotate Left or Rotate Right, which make the delays rotate around the room in the chosen direction. It’s not something you’ll want to do every day, but then again, why not? It’s early days in immersive audio mixing so we should experiment!

Finally, the modulation section has a ‘shape’ drop‑down that’s not in the stereo version, and this provides Triangle, Square, Saw up, Sine, Saw down and Random waveforms.

In Session

I used both plug‑ins when mixing a live album in Atmos, the project being based on stereo stems provided by the producer and stereo mix engineer. My aim was to faithfully capture the vibe and intent of the stereo mixes, yet also put the immersive listener right at the gig, in the venue.

The reverb from the stereo mix had already been printed into the stems, but I was still able to send a little to a 7.1.2 instance of Blackhole, using the output gain controls to take the effect out of the front LCR speakers, thus adding reverb only to the sides, rear and top.

On this particular album, Blackhole was useful on electric guitars and pianos. The reverb from the stereo mix had already been printed into the stems, but I was still able to send a little to a 7.1.2 instance of Blackhole, using the output gain controls to take the effect out of the front LCR speakers, thus adding reverb only to the sides, rear and top. This succeeded in creating the sense of an immersive space, but with all the main energy still coming from the front speakers. More ambient‑sounding guitars benefited from a longer Blackhole reverb, with a little Tilt to lessen the effect at the front of the room, where the guitars were placed, and enough in the rears to give a sense of the sound being ‘around you’. I found that with these more ambient and dense textures, the mix remained clear and uncluttered, even when checking the folded‑down binaural and Apple spatial audio versions in headphones. I ended up using MicroPitch on a stereo keyboard pad. It subtly spread the keys around the room in such a way that you almost didn’t realise it was doing anything until you took it away. So it was an unobtrusive effect, but it still served to pull the listener deeper into the immersive experience.

Conclusion

Blackhole is an awesome‑sounding, dense‑yet‑transparent ambient reverb, and the immersive version lets you tailor the sound in incredible detail across the entire multi‑channel array. It’s more CPU‑hungry than many other multi‑channel reverb plug‑ins, but if you want huge, lush, ambient soundscapes this plug‑in does it better than most. As you’d expect, given Eventide’s decades of experience in pitch and delay processing, MicroPitch Immersive is pure quality. It can be subtle or produce more in‑your‑face creative pitch changes or modulation effects, and tight panning delays in the Immersive world. If you work in immersive music, these will be very desirable tools!