Altiverb 6
Lagenoord 26 3513 GW Utrecht The Netherlands Phone: ++31-30-2433606 Fax: ++31-30-2438500
[email protected] www.audioease.com
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Altiverb 6
Altiverb™ Copyright © by Audio Ease. All rights reserved. Altiverb™ IR Pre-Processor Copyright © by Audio Ease. All rights reserved. No part of this documentation may be reproduced or transmitted in any form by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from Audio Ease. All trademarks or registered trademarks are the property of their respective owners. The Impulse Responses that Audio Ease BV supplies with Altiverb™ are intended for use only in Altiverb™ and may not be used for any other purpose. (Re-)Sampling of the Impulse Responses that Audio Ease BV has supplied with Altiverb™ is expressly prohibited. Copyrights may apply when you sell, lend, hire or give away sampled Impulse Responses from hardware (reverb) units. Check the documentation of the unit that you want to sample when you intend to do so. Venue rights may apply when you sell, lend, hire or give away sampled Impulse Responses from real acoustic spaces. Consult the owner of the venue when you intend to do so.
Altiverb 6
Contents Introduction 5 About the documentation 7 TDM 7 Altiverb at a glance 9 Altiverb’s channel configurations 11 Altiverb reference 15 The Impulse Response Browser The Impulse Response Function Popup Menu Presets Reverb Time (Room) Size Reverse Reverb The Time-Frequency, or Waterfall Diagram Waveform The Info Screen Recording Layout The Info and CPU Screen Google Earth Placemark Damping and Gains Section The Direct Sound The Early Reflections (Early Refs) The Tail Early Ref & Tail on/off Stage Positions Stereo link edit Equalizer The Options section Update on mouse up Efficient high latency mode IR Load - set fully wet Test sounds - Trigger on parameter change Test sounds - Trigger by keys QWER-ASDF Tail Cut Input Gain & Output sections Input & Output Peak Program Meter Level of Front Outputs (Altiverb XL) Level of Rear, or Surround Outputs (Altiverb XL) Center Bleed (Altiverb XL) LFE (Sub Woofer) Bleed (Altiverb XL) Wet/Dry Mix Mute Direct
Altiverb and High Sample Rates Index
16 17 18 20 20 20 20 21 22 22 22 22 23 24 25 25 25 26 26 27 27 27 27 28 28 28 28 28 29 29 29 29 29 30 30
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Altiverb 6 Introduction
Altiverb 6 Introduction
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Introduction 1. Welcome. Altiverb has come a long way since it premiered as the first real-time convolution reverb plug-in in 2001. Audio Ease is glad to welcome you to Altiverb version 6, the state of the art of reverb based on real spaces.
2. What is Altiverb and how does it work ? Altiverb makes your audio sound as if it was played back somewhere else, adding the acoustics of existing spaces to your own recordings or to your live audio. The shortest impulse in digital audio is a single sample ‘spike’. That’s just one loud sample, surrounded by silence. Playback of this spike in a church would create a reverb tail, a response very similar to that of a hand clap. We call the spike’s reverb tail the impulse response of the church, and we make a recording of it. Think of a sampled waveform as a stream of these spikes. The fact that one is louder than the next creates a waveform, but the spikes are almost identical: only differing in their loudness. Now extend every spike in the waveform with the full church impulse response recording, effectively giving each sample its own reverb tail, and it will sound as if the waveform was played back in the church. The process of extending each tiny sample with a scaled impulse response (‘IR’) is called convolution. Altiverb™ is a convolution engine that comes with a vast library of Impulse Responses recorded in real acoustic spaces. It lets you combine your input sound with any of these acoustic fingerprints. The included Altiverb™ Impulse Response Pre-Processor software allows you to create your own impulse responses. (At the time of writing of this user guide the Altiverb™ Impulse Response Pre-Processor was not yet available for Windows XP) The two applications together allow you to sample any acoustic environment and apply its sonic signature to the audio of your choice.
Altiverb 6 About the documentation
In Altiverb, use ‘help’ to get instant explanations at your mouse pointer.
Altiverb 6 About the documentation
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About the documentation This user guide covers the functions and controls of Altiverb 6™ for Mac OS X and Windows XP. Some topics concerning Altiverb™ outdate quicker than others, or are of interest to a small subset of Altiverb users. These topics are not available in printed form and are covered in several PDF files that can be found in the “Altiverb™” folder after installation. So if you are looking for keyboard shortcuts in Cubase on Windows XP, find the appropriate file in the Host specific descriptions folder. If you need instructions on how to sample your own spaces go to the Making Impulse Responses folder. TDM This also applies to the TDM version of Altiverb XL. So if you are confused because you see 15 Altverbs in your ProTools TDM plug-in popup, find out which is which from the ProTools TDM document in the Host specific descriptions folder. Do use the help feature by clicking the question mark in the lower right of Altiverb 6’s interface. It’ll give you instant explanations at your mouse pointer.
Automation presets Global Presets Move input audio around on stage.
Equalize
Damping section
More info on the selected IR.
Test Sounds Gains for Input, Output and surround (XL)
View a waveform diagram of the selected IR.
IR Gains Section
View a waterfall diagram of the selected IR.
Select a room (IR).
Various preferences
Changes the reverb length. Changes the room’s size. Reverses the Reverb
Wet/Dry Mix
Altiverb 6 Altiverb at a glance
Altiverb 6 Altiverb at a glance
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Altiverb at a glance The picture on the left very briefly discusses every user interface element of Altiverb.
Basic operation: Insert an Altiverb into your song. Play back your audio through it and it should already sound as if it is played back somewhere else. Select another acoustic environment by clicking the IR Browser tab. Open a category in the left column, for instance Concert Halls Large, and select a specific venue, for instance Konzerthaus Vienna Large Hall. In the right browser column a number of microphone setups that were used to capture this venue appear. These are the actual impulse responses. Click on either of them to listen. The reverb sound of a selected Impulse Response can be changed by controls. Some only show when you click a section buttons: When you have inserted Altiverb in an aux channel, you want Altiverb’s mix knob to be set completely wet, and you want to check mute direct right under it. The reference section starting on page 15 discusses each control in detail.
About the knobs All parameters controlled by turning knobs can be increased by clicking on them and dragging upward, or to the right. The parameter value will be displayed while you are adjusting. Double click a knob, and you can type in a value. You can hold down modifier keys such as Alt while operating a knob for extra precision, or to restore to default. Which modifiers to use depends on what host application you use. Look up your host application in the Host specific descriptions folder in the Altiverb 6 folder on your hard drive.
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Altiverb 6 Altiverb's Channel Configurations
Microphones pick up...
...what the on-stage speaker plays back.
Altiverb’s Outputs
Altiverb’s Inputs R
R
L
L
Think of Altiverb as an echo chamber. You feed your audio to the speaker(s) in the chamber, place some microphones in there, and get back the reverberated audio into the mixing board. The input of Altiverb goes to the speakers, the output of Altiverb is what the microphones produce.
Altiverb 6 Altiverb's Channel Configurations
4 Altiverb’s channel configurations Think of Altiverb as an echo chamber. You feed your audio to the speaker(s) in the chamber, place some microphones in there, and get back the reverberated audio into the mixing board. The input of Altiverb goes to the speakers, the output of Altiverb is what the microphones produce. The illustrations on the left show an impulse response recording session, and a resulting configuration in Altiverb. The lower diagram is of the type that is visible in the Altiverb interface. The bird’s eye view displays a stereo to stereo impulse response: stereo material is played back on stage via a left-stage and right-stage speaker. Stereo audio is then picked up in the room by two microphones. Audio Ease Impulse Responses (IRs) come in the following configurations, visible in the Browser: Altiverb Regular:
1 in, 1 out ( IR was made using 1 stage speaker position and 1 mic) 1 in, 2 out ( IR was made using a central stage speaker and 2 microphones) 2 in, 2 out ( IR was made using left & right speaker positions and 2 microphones)
Altiverb XL adds:
1 in, 4 out ( IR was made using a central stage speaker and 4 microphones) 2 in, 4 out ( IR was made using left & right speaker positions and 4 microphones)
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Altiverb 6 Altiverb's Channel Configurations
The number of outputs of Altiverb corresponds to the number of outputs of a track, and likewise Stereo output IRs appear on stereo tracks. The mono or stereo icons after the IRs name indicate the amount of inputs of the IR (the amount of speakers you are playing back your audio through into the room). Altiverb (Regular):
If you select a mono input IR on a track that plays back 2 channels, both channels are mixed together before being fed to the IR. The mix knob will still pass Stereo audio when turned towards dry though. If, on this track, you would insert a stereo input IR each channel would get its own speaker on stage. This Altiverb is inserted into a stereo track. This IR will mix both inputs to mono, and be lighter on the cpu while this IR will play back each channel of the input audio through its own speaker on stage.
A mono input IR will take less power form your CPU, but you can only hear the central stage position in it. Any signal that enters Altiverb’s left input channel will end up in this central speaker. When Mute Direct (page 30) is checked, this normally is not a problem. The dry signal controlled by the Mix control (page 30) is never touched, which means that even when the input is mixed to mono before it hits the impulse response, the dry signal remains stereo. Altiverb XL:
If you select a mono input IR on a track that plays back 5.1 channels, all 5.1 channels are mixed together before being fed to the IR. The mix knob will still pass 5.1 audio when turned towards dry though. If, on this track, you would insert a stereo input IR L, Ls and half of the center channel and lfe are mixed to the left input of the impulse response, and R, Rs L, Ls and half of the center channel and lfe are mixed to the right input of the impulse response.
Altiverb 6 Altiverb's Channel Configurations
In tracks consisting of 5 or 5.1 channels, the Center (Bleed) control becomes available. Center Bleed outputs a delayed sum of the rear channels into the center channel to fix possible gaps. It is intended for post production usage to prevent dry dialogue in the center channel, or gaps in the reverb image in wide theater setups. For all musical purposes the recommended setting is all the way down (no center (bleed)), as quadraphonic reverb (L R Ls Rs) has so far produced superior results to 5 or 5.1 channel reverb. So while a fifth reverb output channel is available through center (bleed), the actual impulse response has still been recorded using 4 microphones. The lfe (Bleed) control (for the dot-1, or subwoofer content channel) is much like the center (bleed) control described above. The only difference is that apart from creating lfe reverb, the lfe (bleed) control also governs the amount of lfe content that is input to Altiverb.
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Session Presets Global Presets
Page 18
Damping section
Page 24
IR Gains Section
Page 23
Page 28
More info on the selected IR.
Page 22
Gains for Test Sounds Input, Output and surround (XL)
Page 28
View a waveform diagram of the selected IR.
Page 21
Move input audio around on stage.
Page 26
Equalize
Page 27
Various preferences
View a waterfall diagram of the
Page 20
Select a room (IR).
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Page 27
Changes the reverb length. Changes the room’s size. Reverses the Reverb
Page 20
Wet/Dry Mix
Page 30
14 Altiverb 6 Reference
Altiverb 6 Reference
5 Altiverb reference This chapter discusses each user interface control of Altiverb 6 in detail. All parameters controlled by turning knobs can be increased by clicking on them and dragging upward, or to the right. The parameter value will be displayed while you are adjusting. Double click a knob, and you can type in a value. You can hold down modifier keys such as Alt while operating a knob for extra precision, or to restore to default. Which modifiers to use depends on your host application. Look up your host application in the Host specific descriptions folder in the Altiverb 6 folder on your hard drive.
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Altiverb 6 Reference
The Impulse Response Browser Click or shift-click a room to make available it’s IRs. Double click a room to make available its IRs in the right hand column. Double click to instantly select the Audio Ease preferred microphone configuration The currently within that room. selected IR
These are the IRs (mostly microphone setups) available in the selected room(s) in the left column. Hover over them to view in the info screen. Click to select and listen.
A category of rooms A room of which the IRs are visible in the right column
The stereo symbol indicates this IR has two inputs. All selectable IRs have as many outputs as the track or aux Altiverb is inserted in.
Use the IR Browser to select a sample of an acoustic environment, hereafter called a room, or an IR. Open a category of rooms to select a particular room on the left, and an actual IR, a microphone configuration within that room, in the right hand column. Double click a room, such as Amsterdam Concertgebouw, to instantly select the Audio Ease preferred microphone configuration within that room. Shift-select rooms to make all IRs of multiple rooms appear in the right hand column. Switches the IR Browser’s font size. Contains several functions in a drop down menu. The functions are described on the next page.
Altiverb 6 Reference
The Impulse Response Function Popup Menu Menus are available in the bottom bar of the IR Browser.
Re-scan IR Folder - This re-scans the currently selected impulse responses folder for changes or additions and updates the popup menu accordingly. Select different IR folder - Navigate to find a different folder of impulse responses. Reveal IR folder in OS - Commands the Finder (mac) or Windows to show you the opened, currently selected Impulse Response folder. Show IR Folder in Finder / Explorer - Commands the Finder (Mac) or Explorer (Windows) to reveal the currently selected Impulse Response folder. Analyze Impulse Responses - This analyzes all impulse responses in the group of the currently selected IR. The goal is to obtain information like the location of the direct sound and the decay rate of the reverb tail. This information is needed for many parameters in Altiverb to function properly. All Audio Ease impulse responses and Impulse responses you make with Audio Ease software already contain this information, but many third-party impulse responses may not. Adding Audio Ease Impulse Responses, or IRs made using Audio Ease software.
Audio Ease regularly posts new impulse responses to www.audioease.com/IR. To add them to the menu just download the ones you want, and double click them. They will install into your current IR folder, and will show up next time you launch Altiverb, or after you’ve selected Re-scan IR Folder. The function Analyze Impulse Responses will not be needed, as Audio Eases Impulse Responses are already equipped with all necessary information for all features of Altiverb to function properly.
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Altiverb 6 Reference
Adding third party impulse responses that are not made using Audio Ease software:
1. Use the Reveal IR Folder in OS function to open up the current impulse response folder. 2. Add Wave, sdII or AIFF files, split or interleaved stereo (or just a single mono file) to the folder at any level. Create extra sub folders when needed. 3. Return to Altiverb and select Re-Scan IR folder. The New IRs will be visible. 4. Some features of Altiverb will not work with the new IRs until they have been analyzed. In each new group (folder) of IRs select a single one, and choose Analyze Impulse Responses
Presets The complete state of Altiverb can be saved in a Global Preset, or in a Automation preset. Global Presets are presets that are available across sessions (songs / projects). The Audio Ease made presets are available in this menu. Automation Presets are presets that are saved into the session. They are private to a single instance of ALltiverb and can be recalled via parameter automation. They were called snapshots in previous versions of Altiverb.
The Global Preset Popup Menu Recall a Global Preset by selecting it from this popup menu. If after that you change a parameter, or you recall a Automation preset, the text in this popup will tun to italics. There are several commands at the bottom of the Global Presets popup menu. The save icon below the preset menu is a short cut to either save (when a selected preset has been modified), or save as (when no preset is selected). Open - All presets are separate files on your disk. The preset popup menu by default consists of those found in: /Altiverb 6/Presets/ If you want to load a preset from another location, use this open command to navigate to it. Or use select other presets folder to switch to another preset folder. Save - Replaces the contents of the currently selected preset with Altiverb’s current settings. Save as... -Saves Altiverb’s current settings as a new preset. If you save in the current preset folder, the new preset will be added to this preset popup menu.
Altiverb 6 Reference
You can save the preset somewhere else, but then it will not be shown in this menu. Delete - Deletes the currently selected preset from disk and from this menu. Rename - Renames the currently selected preset without changing its contents. Re-scan presets folder - If you have added (someone elses) preset by copying or moving files in the Finder or Windows, you should rescan the presets folder to force them to show up here. Select other presets folder - Switch to another preset folder. Show Presets Folder in Finder / Explorer - Commands the Finder (Mac) or Explorer (Windows) to reveal the currently selected Presets folder.
Presets - The Automation preset slots A preset stored in an Automation preset Slot is saved in the song or session, while regular presets are saved as separate files in the Altiverb presets folder . The slots can be recalled via automation, for automated reverb changes during playback. A dark numbered slot is empty. The Automation Preset slots are private to a single instance of Altiverb. A light grey numbered slot is occupied. The bright blue numbered slot is currently chosen. Saving a preset in a slot: Click on an empty slot. The now occupied slot will turn light grey (occupied). Emptying a slot: Click the garbage can icon once. The occupied slots will start to blink. Choose one by clicking it. The slot is emptied. You can also command (or apple) -click an occupied preset slot to delete its contents. Overwriting an occupied slot: Empty first, and then save in it, or hold down Alt while clicking an occupied slot. Recalling a Automation preset: Click the numbered slot that holds the preset you wish to recall. Automating Automation preset recalls: Automation preset is available as a parameter in the automizable parameters list of your sequencer, so you can graphically edit the recalls. Alternatively you can manually recall while recording automation data. Some host applications may not support automated Automation preset recalls. Please refer to your sequencer’s document in Host specific descriptions in the Altiverb folder.
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Altiverb 6 Reference
Reverb Time Use this to lengthen or shorten the reverb tail. It applies an exponential gain curve to the impulse response that either increases gain as time progresses (lengthening) or decreases the gain (shortening). By lengthening the reverb time you are raising the level of the softest part of the reverb tail. Please note that that may reveal resolution and signal-tonoise inaccuracies of the impulse response recording.
(Room) Size
Makes the selected room (impulse response) smaller (turn counter clockwise), or larger (turn clockwise). It transposes room modes and resonances, tightens or spreads early reflections, and shortens or lengthens the reverb tail.
Reverse Reverb
Reverses the complete length of the reverb tail that is being convoluted. The actual length of the reverb tail that is convoluted–and then reversed–is dependent on the Tail Cut parameter from the Options Section. In Altiverb XL TDM the length of the reverse reverb is also limited by the version you insert in your track. More info is in the Host Specific Descriptions folder in the Altiverb 6 folder.
The Time-Frequency, or Waterfall Diagram
Shows the reverb’s frequency content through time. The vertical axis (pointing upward) is the decibel axis. The color scheme (beginning briefly with white, quickly moving through blue, and slowly through red and yellow) is repeated every full second of the reverb tail to indicate time. A regular waveform is plotted next to, and time aligned with, the waterfall to give a clearer picture of the reverb’s overall amplitude through time.
Altiverb 6 Reference
From this display you will notice immediately that in real-life a room’s high frequencies decay quicker than its low frequencies. Resonances can be seen as well as the effects of the damping, eq, decay, and the various gain parameters. When zoomed in to the first half second of the reverb, the Early Ref and Tail delays can be clearly seen. Click this and then drag in the diagram to rotate the waterfall around Click this and then drag in the diagram to move the waterfall around Click this and then drag up or down in the waterfall to zoom in or out on it Engage Auto Focus mode to automatically spin and zoom the waterfall to the view that is ideal for displaying the results of the parameter you are adjusting. Click this and then drag left-right in the waterfall to display (in seconds) more or less of the reverb tail You can hold down modifier keys such as Alt to use the functions above without clicking on them. Which modifiers depends on the host application you use, and is described in the appropriate document in the Host Specific Descriptions folder in the Altiverb 6 folder.
Waveform
Waveform view shows the waveforms of each of the channels of the current impulse response. Next to the waveforms the Speaker>Microphone indication is printed. R>L therefore means: This is what the Left microphone recorded when the Right speaker emitted the impulse.
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Altiverb 6 Reference
The Info Screen Press to approach in Google Earth
Press to view bird’s eye view, foto’s VR Movie and CPU Usage
Open screen in larger window
Provides information about the selected impulse response. By Clicking the forward and backward buttons (below) the screen scrolls through several items associated with the current impulse response. You can double-click on most items to open them in a separate window at their original size. Most Audio Ease Impulse Responses will show the following items: The Spinning Virtual Reality Movie
The camera pans around to show you the venue where the sample was made. Doubleclick it to view it in a separate window; pan around the venue by dragging the mouse in the movie window. Shift click to zoom in, and control click to zoom out. Recording Layout
Displays how the microphones were set up and where the speakers were at the time the impulse response was recorded. The Info and CPU Screen
Shows credits, the current latency of Altiverb expressed in both samples and milliseconds and the version number of Altiverb. There are percentages for both average CPU usage as Peak CPU usage. Statistics & Photos
Gives information about the recording and the venue itself, its history, and the gear used to make the sample. Foto’s Show the interior and exterior of the recorded venue. Google Earth Placemark
You can doube click the the placemark icon in the top right to open up Google Earth and fly to the location of the venue. You can download Google Earth for free at: http://earth.google.com
Altiverb 6 Reference
Damping and Gains Section The parameters from this section show when you click Think of Altiverb as an echo chamber. You feed your audio to the speaker(s) in the chamber, place some microphones in there, and get back the reverberated audio into the mixing board. The input of Altiverb goes to the speakers, the output of Altiverb is what the microphones produce. Every time the sound in the echo chamber hits any material, the material bounces some of it back, absorbing some other part of the frequency content of the reverb. Three-band damping simulates this effect of absorptive (or reflective) materials such as baffles, curtains, bass traps, people and chairs in a room. These are the damping controls. Switch to view the Waterfall to view its effects.
Low Damping Gain
Turn counter-clockwise to add absorption, which shortens the reverb tail below the first crossover frequency. Turn clockwise to simulate reflective surfaces that make low frequencies decay longer. Low-mid Crossover Frequency
Determines the frequency where mid damping takes over from low damping. Mid Frequencies Damping Gain
Turn counter-clockwise to absorb, which shortens the reverb tail between the two crossover frequencies. Turn clockwise to simulate reflective surfaces that make mid frequencies decay longer. Mid-High Crossover Frequency
Determines the frequency where high damping takes over from mid High Frequency Damping Gain
Turn counter-clockwise to absorb, which shortens the reverb tail above the second crossover frequency. Turn clockwise to simulate reflective surfaces that makes high frequencies decay longer.
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Altiverb 6 Reference
The Direct Sound
Think of Altiverb as an echo chamber. You feed your audio to the speaker(s) in the chamber, place some microphones in there, and get back the reverberated audio into the mixing board. The input of Altiverb goes to the speakers, the output of Altiverb is what the microphones produce. After the sound leaves the speakers, the quickest path to the microphones is in a straight line. This first source to hit the microphone is the direct sound, and its loudness and occurrence in time help you locate the speakers. The chamber itself is not heard in the direct sound, only the coloration of speakers, a bit of air, and the microphones. You can choose to substitute this coloration with a neutral, or flat version. To do this you turn the color knob from IR to flat. Direct Sound Gain
Controls the gain of the direct (first) sound in the impulse response. Turn down direct sound gain all the way if you use Altiverb as a traditional send (aux) effect, because in that situation you just need the actual reverb, which starts after the direct sound. To reach the same effect you can also turn off the direct section using the on/off button in the lower left, or the mute direct check box under the Wet / Dry knob
Altiverb 6 Reference
Direct Sound Color
When set to IR, the direct sound has coloration from the speaker, air and mic. Remove coloration by setting this parameter to flat.
The Early Reflections (Early Refs)
Early reflections come right after the direct sound. They are the first couple of reflections off the walls, ceiling and floor of the chamber. Reducing earlyref gain generally makes the audio more intelligible. It can also make the room sound larger or damped as soft reflections suggest distant or baffled surfaces.
Early Reflections Gain
Controls the gain of the first couple of reflections bouncing off the walls, ceiling and floor. Early Reflection Delay
Delays the first couple of reflections off the walls, ceiling and floor. It simultaneously delays the tail by the same amount to preserve the early reflections/tail connection.
The Tail The tail is next. It’s the long diffuse part that is normally called reverb. Tail Gain
Controls the gain of the long diffuse end of the reverb: the Tail. Tail Delay
Delays the reverb tail, but leaves direct and early reflections in place. Can be set to negative values to start the onset of the tail earlier. Early Ref & Tail on/off
There are situations where you may not need to calculate the tail or the early reflections. This makes it a lot lighter on your computer’s CPU. An application of this can be found in the installed file ‘Simulating the orchestral stage with Altiverb 6.pdf’
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Stage Positions A light means a section is turned on.
Switch a section on or off
Press a button to show the section
Puts your source audio in a particular spot on the ‘stage’ of the sampled room in a convincing, physically correct way. (on/off button is at the top left) Read also the installed ‘Simulating the orchestral stage with Altiverb 6.pdf’ Think of Altiverb as an echo chamber. You feed your audio to the speaker(s) in the chamber, place some microphones in there, and get back the reverberated audio into the mixing board. The input of Altiverb goes to the speakers, the output of Altiverb is what the microphones produce. Starting with the basic rule above, it follows that it also matters where the speakers are in the echo chamber. When the speakers are located on the highlighted spots in the picture, they are in their original sampled positions (as described in the configuration picture in the monitor on the upper right). You can triple the distance between the microphones and the speakers by pushing the speakers all the way to the back of the stage. Triple the width between the speakers themselves by dragging them apart. Halve the original distance from the microphones to the speakers by dragging the speakers all the way to the front. Stereo link edit
mirrors the speaker placement in the center stage line. When a mono input Impulse response is selected (page 12) just one speaker will be displayed. By engaging Stage Positions, you are controlling the timing and loudness of the direct sound. Because of this, Direct Gain and Mute Direct are unavailable while the Speaker Placer is engaged.
Altiverb 6 Reference
Equalizer A light means a section is turned on.
Switch a section on or off
Press a button to show the section
The equalizer works on the wet signal only. The bass and treble bands are Baxandall eq’s, designed to not change phase more than 180%, which effectively means that combing or cancellation effects are unlikely when the eq’d signal is mixed with the dry signal.
The Options section
Update on mouse up
When this is checked, control adjustments will be calculated when the mouse button is released, causing a gap in the audio. When unchecked Altiverb will update parameters while you turn the knobs, without interruptions. The latter is slightly heavier on the CPU. Please note that some controls ignore this setting: EQ is always “live”, as are the input, output, front, rear and test sound gains, and the Wet/Dry Mix. Changing Latency, Size, Tail Cut, Damping On/Off, Reverse, or the chosen IR will always interrupt audio. Efficient high latency mode
Uses a minimum of processing power but can produce a delay of up to a second between input and output. The introduced latency may be compensated for by latency compensation features of the host application (sequencer). To find out about your sequencer please refer to the pdf files in Altiverb 6/Host specific descriptions
Click on the forward or backward buttons below the Info Screen until the technical data page appears to determine the precise amount of delay.
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If, due to uncompensated delay, you get ‘flamming’ effects, turn down direct-sound gain from the damping and gains section, or engage Mute Direct. IR Load - Reset all parameters to default
When this is checked, all parameters will be reset to their default positions when you select a new IR. IR Load - set fully wet
When this is checked, each IR will load without direct sound. The Mute Direct button will be on. If you always use Altiverb in an aux channel turn this on. Test sounds - Trigger on parameter change
Each time you adjust a parameter, the last played test sound will re-play automatically. Test sounds - Trigger by keys QWER-ASDF
The keys from your computer’s keyboard can trigger the test sounds. The upper row QWER corresponds to
.
The ASDF keys trigger only the last played sample from each of the four categories. Turn this feature off if it conflicts with key commands in your host application. Tail Cut
This eases the load on the CPU by shortening reverb tails. If your production does not require reverb tails to decay down to -140 dB, you can instead use tail cut to cut-off reverb when it has died down for instance to -80 dB. As Tail Cut changes the length of the reverb, its effect is more apparent when the impulse response is in reverse mode (page 20). In reverse mode you can use tail cut to tailor the delay of the slap-back effect.
Input Gain & Output sections
Amplifies or attenuates the input and output signals of Altiverb. The amount of controls in the input/output section depends on Altiverb’s number of output channels.
Altiverb 6 Reference
Center channel output (in 5.1 Altiverb XL) is generated via the Center Bleed control. Sub woofer (LFE) channel output (in 5.1 ALtiverb XL) is generated via the LFE Bleed control. Effects are displayed in the level meters. Input & Output Peak Program Meter
These ‘Peak and Hold Meters’. Constantly display the average, or VU, value of input and oputput signal, while momentarily holding the peak or PPM value at the top of the meter (as a floating dot). When Altiverb outputs 4 channels (only in Altiverb XL) the order is: L , R , L surround, R surround When there are 5 outputs of Altiverb XL the order is: L , R , L surround, R surround, C When there are 5.1 outputs of Altiverb Xl the order is: L , R , L surround, R surround, C, LFE (subwoofer)
Level of Front Outputs (Altiverb XL)
Controls the level of the left-front and right-front outputs. It has no effect on the center level. Level of Rear, or Surround Outputs (Altiverb XL)
Controls the level of the left-surround and right-surround outputs. Center (Bleed) (Altiverb XL)
Outputs a delayed sum of the rear channel into the center channel to fix possible gaps. Intended for post production usage to prevent dry dialogue in the center channel, or gaps in the reverb image in wide theater setups. For all musical purposes the recommended setting is all the way down (no center bleed). LFE (Sub Woofer) (Bleed) (Altiverb XL)
Outputs a delayed sum of the rear channel into the LFE channel to allow for reverb in the sub woofer. Intended for post production special effects usage. For all musical purposes the recommended setting is all the way down (no LFE bleed). The LFE knob simultaneously governs the LFE input gain.
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Altiverb 6 Reference
Wet/Dry Mix
Controls the amount of dry (input) signal vs. wet (reverb) signal. Introducing dry signal will interfere with the effects of the direct sound. It may introduce phasing or flamming when used in conjunction with the direct sound. Therefore we recommend you check Mute Direct when you need to add Dry sound. Mute Direct
Use this to mute the direct sound altogether. Similar to turning down the direct gain. This is the recommended way of setting Altiverb up in an Aux channel.
Altiverb 6 Altiverb and High Sample Rates
6
Altiverb and High Sample Rates Audio Ease Impulse Responses are released at samplerates of 48 kHz or 44.1 Khz. 96 kHz versions of Audio Ease Impulse Responses have not been released because no valuable data has been found to return from walls and ceilings in the highest octave (24 kHz - 48 kHz). Altiverb can be used in projects running at the following ‘high’ sample rates: 88.2 kHz, 96 kHz. Altiverb XL adds 176.4 kHz, 352.8 kHz and 384 kHz. Running the reverb engine at these sample rates would place an extremely heavy load on the processor. There is no quality advantage of running the reverb engine at 96 kHz when a 48 kHz Impulse Response is selected. In such a case it makes sense to keep the reverb engine running at 48 kHz, so processor load stays at a reasonable level. An Example
When a 48 kHz impulse response is used in a 96 kHz project, the reverb engine will run at 48 kHz, while the dry sound will stay at 96 kHz. The sample rate conversions performed are of very high quality and are extremely accurate. They introduce a slight delay (typically 64 samples) into the signal path. The exact amount of delay is displayed in the Info Screen (page 22). It is possible that 96 kHz impulse responses will eventually become available. With a 96 kHz impulse response being used in a 96 kHz project, none of the sample rate conversions described above would need to be performed. The reverb engine will run at 96 kHz, resulting in heavier processor load, but true 96 kHz processing. Required buffersizes
The sample rate converters can only function when your hardware buffer size is set to 256, 512, 1024, 2048, 4096, 8192, or 16384 samples. (Check the appropriate PDF files in the folder “Host Specific Descriptions” for more info) If such a buffer size is not available, Altiverb will warn you that it will run its reverb engine at a high sample rate, resulting in heavy processor load.
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Session Presets Global Presets
Page 18 Damping section
Page 24
IR Gains Section
Page 23
Page 28
More info on the selected IR.
Page 22
Gains for Test Sounds Input, Output and surround (XL)
Page 28
View a waveform diagram of the selected IR.
Page 21
Move input audio around on stage.
Page 26
Equalize
Page 27
Various preferences
View a waterfall diagram of the
Page 20
Select a room (IR).
Page 16
Page 27
Changes the reverb length. Changes the room’s size. Reverses the Reverb
Page 20
Wet/Dry Mix
Page 30
32 Altiverb 6 index
Index
