recently unveiled Altiverb, a reverb plug-in for Digital Performer and MAS developed by Audio Ease BV, the Netherlands-based audio software developer.
Altiverb is a sampled acoustics processor that offers one-, two- and four-channel sampled acoustics of real halls, churches, forests, bathrooms, virtually any acoustic environment. Altiverb is the first native reverb plug-in to take full advantage of Altivec, the PowerPC G4 “Velocity Engine” co-processor that’s designed to accelerate multimedia functions. The result is a native reverb plug-in for Digital Performer — MOTU’s audio workstation and MIDI sequencer software for the Power Mac — that exceeds the performance of recently introduced outboard sampled acoustics processors that cost as much as US$10,000, claims Arjen van der Schoot, co-founder of Audio Ease.
“Until the 21st Century, reverb units could only crudely approximate the amazingly complicated nature of real-life acoustics,” he said in a press announcement. “What stereo did to mono, Altiverb’s sampled acoustics will do to synthetic reverbs.”
Sampled acoustics processing takes an enormous amount of DSP bandwidth, and there are only a few pieces of outboard gear currently on the market that can do it, stated Jim Cooper, MOTU marketing director. Look inside ’em and you’ll see dozens of DSP chips, “hence their astronomical price tag,” he added.
“The engineers at Audio Ease ingeniously employed the G4 Altivec processor, which is a solitary monster DSP processor sitting inside every G4 Power Mac,” Cooper added. “In fact, it’s so powerful, the Altiverb plug-in can produce up to 40 seconds of real-time reverb decay, while the outboard ‘verbs are doing about 6-10 seconds. And our careful analysis shows that the quality is the same. Altiverb brings sampled acoustics reverb to any Digital Performer user’s desktop at fraction of the cost of these expensive units.”
Altiverb provides mono-to-mono, mono-to-stereo, stereo-to-stereo, mono-to-quad, and stereo-to-quad effects. All processing is done in real time, and two modes are offered: zero-latency mode (with shorter decay times) and long decay mode.
An Altiverb preset is called an “impulse response,” which is created by firing a starter pistol or by playing a sine wave sweep from a speaker in an auditorium, church, or other acoustic space. The resulting reverberation decay is recorded as a digital audio file. Using a process called deconvolution, the dry source signal is then extracted from the audio file, leaving behind the exact acoustic fingerprint of the space.
The impulse response file is then placed in a folder, where it appears as a preset inside the Altiverb plug-in, where it can then be applied to any audio signal as real-time reverb. The result is a true reproduction of the sound of the acoustic space, according to Coopoer. Unlike reverbs of the past, which attempt to synthesize decay characteristics, Altiverb captures the actual acoustics of a particular environment, he added.
Altiverb includes the Impulse Response Pre-Processor software, which allows users to sample any acoustic space, hardware reverb, or other source to create their own Altiverb presets. In addition, users can take photographs of the place they are acoustically sampling, and place JPG images in the same folder. Altiverb then displays the JPGs as a slideshow when the preset is chosen in the plug-in. Plus, these pictures can show mic positions and other details of the sampled space.
Altiverb is expected to due the second quarter of the year. The price hasn’t yet been announced.