The Zoom2Five plug-in is made specifically for the Zoom H2 portable digital audio recorder. The H2 has four cardioid microphones arranged as a front pair with a 90° width and a back/surround pair with a 120° width. The Zoom2Five plug-in will transcode the H2 quad channel surround output to the 5.1 surround standard found in home theater setups.
The Zoom2Five plug-in is made with SonicBirth, a visual dataflow programming language for the creation of Audio Unit and VST plug-ins for Mac OS X. The Windows OS equivalent of SonicBirth would be SynthMaker.
The Zoom2Five plug-in, and the information on this page, are provided as is, without any guarantee regarding performance or end result. Ambisonic Studio and Daniel Courville are not associated with the manufacturer, distributors or vendors of the Zoom H2 portable recorder.
There's also more surround recordings made with the Zoom H2 available at Freesound.
Mac OS X audio utility downloads
X Lossless Decoder (XLD): utility for converting files between the following formats: Wave, AIFF, raw PCM, Wave64 (.w64), MPEG-4 AAC (.m4a), Apple Lossless (.m4a), FLAC (.flac/.ogg), MP3, Ogg Vorbis, WavPack (.wv). Can also read Monkey's Audio (.ape) and True Audio (.tta). Files can be multichannel if supported by file format.
The Zoom2Five has six inputs, L R Ls Rs (plus two dummy inputs for compatibility purposes), and three different 5.1 output modes.
Front/LR Channel Controls Level: to attenuate the output by up to 24 dB, the default is 0 dB or no attenuation. Directivity: to control the directivity of the virtual microphones feeding the speakers between 1st order cardioid and 2nd order cardioid, with the default to 1st order. Width: to vary the width of the speaker feeds from 0 to 180°, with default to 90°, referenced to Center. Mute: to mute the output, with default to Off, meaning no mute.
Center Channel Controls Level: to attenuate the output by up to 24 dB, the default is 0 dB or no attenuation. Directivity: to control the directivity of the virtual microphone feeding the speaker between 1st order cardioid and 2nd order cardioid, with the default to 1st order. Mute: to mute the output, with default to Off, meaning no mute.
Sub/Lfe Channel Controls Level: to attenuate the output by up to 24 dB, the default is 0 dB or no attenuation. EQ: to control the lowpass filter between 20 and 160 Hz with the default at 120 Hz. Mute: to mute the output, with default to Off, meaning no mute.
Surround/LsRs Channel Controls Level: to attenuate the output by up to 24 dB, the default is 0 dB or no attenuation. Directivity: to control the directivity of the virtual microphones feeding the speakers between 1st order cardioid and 2nd order cardioid, with the default to 1st order. Width: to vary the width of the speaker feeds from 180 to 360°, with default to 240°, referenced to Center. Delay: to delay by up to 35 milliseconds with a default of 0 ms or no delay. Used for augmenting Front-Back separation. Mute: to mute the output, with default to Off, meaning no mute.
Interpolation Control Affects the sound quality of the Surround Ls/Rs delay. The Linear interpolation setting will yield better sound quality, but will use more CPU. Default to No interpolation.
Soundfield Controls Axis Flip: to flip the soundfield on the Front/Back axis (front becomes back) and on the Left/Right axis (left becomes right), both default to Off, no flip. Rotation: to rotate the soundfield, in degrees, from -180 to + 180. Default to 0°, no rotation.
Output Channel Order Control Configures the output channel order. This can be useful in preparing the audio stream for applications that expect the audio channels in a specific arrangement. Apple Logic 8 users should select the third option: L R Ls Rs C Lfe.
Mute unused channels to optimize CPU performance.
Note on the Sub/Lfe: activate the Sub/Lfe when monitoring without bass management. Deactivate (Mute) it when generating the actual stream for the 5.1 media: the Zoom2Five will then output a 5.0 stream, but the media player/surround processor will likely feature bass management if the 5.0 stream is delivered on DVD-Video, DVD-Audio, DTS-CD, SACD, HD-DVD, Blu-ray disc or HDTV broadcast. More details on the use of the Lfe channel available here.
Once the Zoom H2 four channel surround stream is converted to 5.0 or 5.1, a Dolby Digital encoded DVD-Video or a DTS encoded Audio-CD can be easily created.
Dolby Digital To create a Dolby Digital encoded DVD-Video, Apple Compressor or ffmpegX is used for the encoding and Apple DVD Studio Pro or Roxio Toast for the DVD authoring.
With Compressor, the 48 kHz / 24 or 16 bit mono files (one per channel to be encoded) are fed to Compressor. Suggested settings are to adjust the dialogue normalization to -31 dB, Center and Surround channels downmix to -6 dB and to turn off the 90° phase shift in the Surround channels. The bitrate should be set to the maximum allowed on DVD-Video, 448 kbps. In the case of a 5.0 mix with source files at 24/48, the size of the resulting AC3 (Dolby Digital) file will be about twelve times smaller than the total source files.
With ffmpegX, the 48 kHz / 16 bit six channel interleaved file (L C R Ls Rs Lfe) is fed to ffmpegX. Unlike Apple Compressor, there is no settings other than to select the "Audio file to AC3" preset in the Target format drop-down menu.
This AC3 file is then imported in a DVD Studio Pro project. With a very basic menu and a still image as video track, the resulting DVD-Video can be burned directly from DVD Studio Pro or exported as a DMG file that can be distributed and later burned with software like Apple Disk Utility, Burn or Roxio Toast.
As an alternative, Roxio Toast (version 8, 9 or 10) has a DVD authoring mode called Music DVD (Audio Menu) that allows easy creation of DVD-Video for audio-only playback. To avoid the multichannel AC3 files from being downmixed and re-encoded to Toast default two channel AC3, the files have to be dragged to the Toast window while pressing the Option (Alt) key. Toast will create a menu for the DVD and a still image for each track.
It should be noted that AC3 files are directly playable with the VLC Media Player. One could then also include on a DVD-Video a non-multiplexed AC3 file, thus giving the end-user more playback options. Such a file, to be directly read by a software player, could use the maximum possible bitrate of 640 kbps allowed for a generic AC3 file and a 44.1 kHz sampling rate since it won't be tied in with a video stream.
DTS To create a DTS encoded Audio-CD, Vortex Surround Encoder is used for the encoding and Apple iTunes, Burn or Roxio Toast for the CD burning.
The 44.1 kHz / 24 or 16 bit mono files (one per channel to be encoded) are fed to Vortex Surround Encoder. Beside selecting DTS as the output format, there are no settings to adjust. In the case of a 5.0 mix with source files at 24/44.1, the size of the resulting DTS data, in a WAV file container, will be about 3.75 times smaller than the total source files.
The DTS-WAV file is then imported in a standard Audio-CD burning application like Apple iTunes, Burn or Roxio Toast. Once the DTS-CD is ready, care should be taken not to play the CD undecoded, since it will output continuous white noise. If placed in a standard CD player, the player must output the data through a digital link to a surround decoder such as the ones found in home theater installations. If placed in a DVD-Video player, the DTS data will be either internally decoded in the player or again externally decoded with home theater components.
DTS-WAV files are also directly playable with the VLC Media Player.