Organic Variance

Unlike convolution reverbs, Aether is not a static process, and no two instances of Aether are ever exactly the same. The same is true in real world acoustical spaces as well: a building's acoustical character may vary slightly depending on several factors such as its current occupancy, and even more subtle things such as the current temperature and humidity. Thus, acoustic space itself is alive in the real world and is constantly shifting, morphing, and evolving to produce a complex array of potential impulse responses. A sampled impulse response of a real acoustic space, can be quite accurate for that particular moment, but it tells only part of the story. It is like a picture of a lake, versus the lake itself. A lake in the real world is unlikely to spontaneously develop waves the size of those found in the ocean, but it is never quite as still as a picture either. Aether's approach does not simply sample one static picture in time, but rather captures the complete subtly of the dynamic chaotic processes found in life and it retains all the detail and organic feel of these processes. Aether is alive!

Non-Exponential Decay

Reverb energy in nature decays exponentially - that is to say that it decreases rapidly after the sound source has stopped emitting sound. This is probably a good thing in nature as we would not want to hear a thunder boom continue on for weeks after the lightning strike! In musical applications, however, often we would like the reverb to remain higher in volume for a little longer as to augment the sense of space around a particular instrument. When using traditional exponentially decaying reverb designs, producers and engineers often resort to raising the gain of the reverb to achieve this goal. They soon realize, however, that the rest of mix gets muddy very quickly, and so they reach for their gates to compensate for this problem. This of course results in its own set of complications, and in the words of the immortal Wesley Snipes, is a bit like trying to ice-skate uphill. Aether offers two controls, Spread and Sustain, to keep the energy in the reverb tail higher a little longer than normal without muddying the mix and still allowing a natural decay down to negative infinity. Aether also offers an Attack control to shape the reverb tail's attack envelope to allow for slower build-up as is found in larger buildings. These combine to provide the ultimate control over the time envelope of the Late Reflections. For more information on this topic, please download the Aether Manual available in the Links and Downloads section above and read the "Understanding Aether's Time Envelope Controls" section.

Ster-E-Oh-My-God

Most software reverbs on the market are effectively Mono-to-Stereo processes and even when they are inserted on a stereo track, the stereo input is first summed to mono and then fed into the reverb. This is fine for mono sources, such as lead vocals that are panned dead center, but it is generally not desirable for stereo sources or for use on send busses where several panned instruments share the same reverb. The problem with this is that the stereo image of the source is collapsed and lost in the diffusion of the omnidirectional reverb. In such cases the spatial information and panning of the source is disregarded and all sources are assumed to come from one point within the reverb. Ultra high-end hardware companies have known this for decades and offer advanced modes including True Stereo and Dual Mono. Aether offers the same modes in software form, and goes one step further by offering "Cross" and "Width" controls that allow the reverb to blend seamlessly from Dual Mono, to effectively a Summed Mono input, to Dual Mono with reversed channels, and anywhere in-between. Finally, Aether also offers the traditional Mono-to-Stereo mode to reduce CPU usage when needed. For more information on this topic, please download the Aether Manual available in the Links and Downloads section above and read the "Understanding Cross and Width" section.

Aether 1.5 now offers the choice of four stereo modes for both ERs and LRs. Furthermore, these modes can be set independently, which when used with the new Cascade control, can create an entire universe of interesting new spatial effects.

• L-R Mono: A Mono-to-Stereo process where Cross controls the Left-Right input balance. For example, add reverb to only the Left channel input from a stereo input, or collapse the input to center and use this mode to save CPU usage. • L-R Stereo: A Stereo-to-Stereo process where Cross controls the relative input position of the source. This mode achieves true stereo, dual mono, reversed panning, partial mixing of channels to give variable degrees of source separation, and complex 3D dimensionality when used with Cascade. • M-S Normal: A Mid-Side process where Cross controls the Mid-Side input balance! For example, add reverb to only the side signal from a stereo input, or the mid signal, or some mix of the two. This allows centered mono instruments to stay dry while adding extra reverb or ambience to the supporting instrumentation, and is excellent for mastering needs! • M-S Relative: A Mid-Side process where Cross controls the relative Width of the reverb signal and Width becomes an output panner! For example, feed Aether a mono signal, and receive a mono output. Feed it a wide stereo signal, and receive the same output. Or reverse the behavior! This mode is excellent on omni-directional sounds such as synth pads and ambiences or dense mixes which already contain complex spatial information, and is excellent for special FX use!

Freq Out

And keep only what you want. Aether employs an industry first, advanced frequency dependent decay time scaling process that allows users to specifically sculpt and carve custom reverb damping curves with unprecedented flexibility. Aether divides the audio frequency range into three frequency ranges and allows each frequency range to have its own time scaling factor. To add further flexibility the "Q" or filter slope of both filter cut-off points is adjustable from 0.05 to 1.00 to allow extreme variance from gentle sloping curves to extremely steep ones. This allows the users to keep the mix clean in critical bands while allowing more space in others, and it allows preset designers to achieve both ultimate realism and intentional supernatural effects.

All frequency control settings in Aether 1.5 can be set at full frequency range from 8.00hz to 32,768.00hz. In other words, Aether 1.5.0 offers a twelve octave frequency response range. Infrasonic (<20hz) and ultrasonic (>20kHz) frequency cutoffs can be useful to achieve gentle roll-offs of extreme frequencies within the hearing range. Furthermore all filters have phase characteristics which are generally most severe at their cutoff points, so moving the cutoff outside the traditional range of human hearing can be desirable for those obsessive enough to care about such things. Additionally, Aether 1.5.0 allows filter routing to be reversed. In version 1.0, the EQ was always an input EQ and the HF Soft filters were always on the output. Aether 1.5 offers a button to reverse this behavior and put the HF Soft filters on the input and the EQ on the output. This can be useful for high pass and narrow-band needs.

Maximum Modulation

In addition to the intrinsic variance found at the very heart of the Aether algorithm, Aether also offers even more modulation possibilities to keep the verb from sounding dead and static. Two simple modulation controls are offered to invoke additional random LFO modulations in the Late Reflections section of the algorithm. The Modulation Rate and Period controls create musically-pleasing, randomly shifting resonances in the spectrum of the diffuse Late Reflections. Modulation period length extends to over eight minutes to allow for imperceivably slow shifts in the resonance of the reverb tail that guarantee the reverb sound will never be exactly the same over the course of an entire song. This completely eliminates the metallic sound which plagues many inferior reverb designs on the market. In Aether 1.5, the modulation Period range has been vastly expanded and the modulation rate is allowed to move into the audio range in the extreme setting which can make the it behave like chaotic FM synthesis. This can be very useful for novel special effects.

Beyond Reality

Don't be limited to only that which you can capture with a microphone. Why contract NASA to build you a $10 billion, 1000-meter geodesic dome made out of the latest nano-material buckyballs to provide a negative refractive index so that you can run your sine sweep impulse through it and capture a static IR? Instead, simply use Aether in some extreme settings to achieve the result you are after. Want a 120 second reverb that decays quickly in the mid range, but sustains more in the highs? Need a reverb that decays infinitely in a one octave mid-range band while all other frequencies fall always quickly, and at the same time reverses it's panning of the late reflections? No problem. Have it your way! You are limited only by your imagination.

Aether 1.5 offers ER Pre-Delay to allow ERs to be independently delayed from LRs. This is useful for creating "slap-back" type presets and special FX, and modeling large outdoor spaces which have distinct echoes late in the tails. Additionally, Many parameter ranges have been vastly increased to allow more extreme settings and explore new possibilities. For example, maximum ER Size has been changed from 100 meters to 250 meters and LR Size range is now also 1 to 250 meters, whereas previously the range was about 3 to 60 meters. This change thus represets a ten-fold increase in the Size range, is generally at least four or five times larger than the competition, and opens up a whole new universe of creative possibilities.

Cascade & Porter

As mentioned elsewhere, Aether is comprised of two separate and distinct stereo engines. In earlier versions of Aether and all other products on the market that we are aware of, these two engines alway operate in parallel. Aether 1.5 introduced the Cascade control. The Cascade control allows Aether to run in Serial modes where the output of ER Engine is fed into the LR Engine, or vice versa. The Cascade control does not simply force the user to choose between parallel or serial operation however. Instead, it allows the user to seamlessly morph between these two modes and create hybrid states whereby some of the output signal of a given Engine is fed into the other Engine, and some is fed directly into the master output. This allows for tremendously flexible signal routing which is all accessible from a single control. Cascade has several uses:

• Perceptually recede the ER reflections back into the depth of the stereo field to deepen the sound stage perception. • Glue the ERs and LRs together to some degree to function as a synergistic whole. • Aid in the creation of 3D sound-fields via careful use of Stereo modes and Cross • Add additional density to the resulting composite system impulse response • Impart the coloration and characteristically uneven frequency response of the ER Engine into the LR Engine to various degrees to roughly model room modes in acoustical environments • Assist in creating very dense composite impulse responses which are useful for Non-Linear, Plate, and Ambience type of presets • Model large irregular and asymmetric acoustic spaces where there is a sense of semi-discrete, clustering, grain-like, or "chunky" behavior later on in the tails • Emulate Physical-Modeling-like behavior of highly chaotic small systems which exhibit strong comb filtering effects and resonances • Special FX creation. The Cascade control becomes even more powerful when one considers the other new Aether 1.5 features. With careful use of settings the user can allow Aether to function almost like a three engine device where it can provide a third ghost output signal component which is a sophisticated hybrid between the two existing engines.