By Ryan McCambridge
Exponential Audio Stratus & Symphony Reverb Plug-Ins
You may not have heard of Exponential Audio , and in telling you , I may be breaking some sort of Masonic audiophile code . Their plug-ins are like a secret handshake amongst audio professionals . Those who know , know .
If you ’ re feeling out of the loop , rest assured that you at least indirectly know Michael Carnes , who is the lifeblood of Exponential Audio , through his nearly 25-year career at Lexicon developing some of the most iconic digital reverbs out there . Carnes started Exponential Audio in 2012 and has since become a leader in reverb plug-in development . PhoenixVerb and R2 , along with their surround counterparts , have become indispensable tools to many mixers , especially those in post-production . But with advancements in immersive formats and new ground being covered with their NIMBUS and R4 stereo reverbs , Exponential Audio has now released Stratus and Symphony , very likely the most sophisticated surround reverbs available .
The Basics Both Stratus and Symphony will run as 64-bit AAX , AU , VST , or VST3 plug-ins and though they are natively surround reverbs supporting mono though to 7.1 channel formats , they have 3D versions as well , which handle immersive formats like Atmos and Auro-3D . Choices are very limited for reverbs that work in 3D formats ; in fact , I ’ m not sure of any other plug-in reverb that was designed at its inception to be an “ immersive ” reverb . Even still , each of the reverbs ’ channels are de-correlated , so changing the channel format of an instance of Stratus or Symphony won ’ t colour the sound , which is helpful when delivering in multiple formats .
In Use As with Exponential Audio ’ s previous generation of surround reverbs , Stratus and Symphony are differentiated by their algorithms and , loosely , their purpose . Stratus ’ ancestry is derived from NIMBUS and PhoenixVerb , focusing on naturalness and recreating spaces accurately . Symphony , on the other hand , follows the R4 and R2 lineage , which are lush and capable of rich modulation and chorusing .
While testing Symphony and Stratus side by side , the distinctions between the two were obvious and I could see unique applications for both . Carnes cites Symphony for use with music and score and Stratus for foley and dialogue , but he ’ s also quick to note that mixers have found success in the opposite . As with all aspects of mixing , the content dictates which tools are best used , but broadly speaking , I would say that Symphony would shine in moments where there is enough space for the reverb itself to be its own element in the mix . Stratus , on the other hand , would be better for subtlety , where you ’ re not necessarily trying to draw a listener ’ s attention to the reverb . This of course doesn ’ t mean that the inverse can ’ t be achieved ; however , Symphony is definitely a “ bigger ” reverb , which I could see being too substantial and effected for some situations . Symphony also differentiates itself with its gating abilities and a “ Freeze ” function that can infinitely sustain the reverb tail for interesting effects .
Stratus and Symphony are capable of an incredible amount of tailoring . This means that the energy of the reverb can be focused based on your mixing needs and elements of the reverb can be manipulated with a surprising amount of specificity . This includes granular control over both the early reflections , which are twice as dense as PhoenixVerbSurround and R2Surround , as well as the reverb tail . This level of detail in the early reflections helps with realism through directional accuracy and overall perspective within the reverb . This is really where the evolution of digital reverberation lies .
I can ’ t outline every parameter that can tailor the reverb , but aside from all of the relatively conventional reverb functions , Stratus and Symphony have some original offerings . Both plug-ins have width adjustment for the reverb tail , which can create some interesting widening effects , but Symphony also adds a width slider to the early reflections . There are also very extensive EQ options for the early reflections and tail , as well as an additional input filter , which can add clarity to the reverb by regulating the incoming frequencies .
The input is also one of the available sources for keying the “ Tail Suppress ,” which creates interaction between the source and the reverb by attenuating the reverb level based on the incoming signal . This helps maintain focus on the source by mitigating reverb wash and only pushing the reverb level up when the signal itself isn ’ t present .
Deviating further from typical reverb customization , Stratus and Symphony have “ warp ” sections that house a compressor / limiter , a bit crusher for reducing bit depth , and an overdrive circuit with several flavours of distortion and saturation . These functions were added to give character and allow the user to create low fidelity , vintage emulations in spite of the intrinsic sophistication of these reverbs . Tempo setting and host sync are also available , both of which are typical ; however , the addition of pre-delay sync allows the predelay to be set as a note division to the set or synced tempo , alleviating the need to use a delay time calculator . Impressive .
Putting any of my negative opinions in print seems almost vapid given how insignificant they are . The GUIs are designed to be functional , in an effort to allow scaling and minimize CPU demand . Ultimately , I respect that Exponential Audio ’ s efforts were put towards aspects that really matter , but those looking for a beautifully rendered hardware
STRATUS
SYMPHONY 3D
mockup will not find it here . This is perfectly fine in my books , but there are a few functions that weren ’ t immediately obvious in their design . Of course , that was mitigated the more I used the plug-ins .
Some users might also find these reverbs overwhelming , though there are Tooltips to help explain each parameter and many exceptional presets , which can be searched and categorized . Though Stratus and Symphony are not designed for novices , those willing to put in the time with them will be rewarded .
Summary It ’ s no surprise that Exponential Audio has become a staple in post-production mixing . Part of what makes these reverbs so exceptional is that Exponential Audio is one of the few companies that seems to focus on its surround products as much as their stereo counterparts , if not more so . More importantly , Carnes recognizes that reverb is alive and sees it as more than just a means of artificially recreating space . He asks how reverb is being used in mixing and gives us tools that are as adaptable as the content is diverse .
I ’ m not one for dramatic statements but I have to give credit where it ’ s due : Stratus and Symphony may very well be the best-sounding and most comprehensive reverb plug-ins available . They are so clearly the culmination of a career dedicated to the specific challenges of digital reverberation , and quite frankly , they are a stunning achievement that will certainly propel the quality of surround and immersive mixes for years to come .
Ryan McCambridge is a freelance producer , writer , and engineer whose credits include Rush , Birds of Tokyo , and Glass Tiger . He has taught sound design and production at workshops and universities and is the frontman of A Calmer Collision . For more information , visit www . ryan-mccambridge . com and www . acalmercollision . com .
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