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.