Audio Engineering Society Swiss Section
Newsletter 91th issue
Recording and Application of the
3-dimensional 2+2+2 format
Friday 3 rd of Octobre 2003 at Konzertsaal Radio DRS Bern, Switzerland
Speaker: Werner Dabringhaus, Dabringhaus und Grimm Audiovision
GmbH
Organizer: Gabriel Leutzinger
About 25 participants gathered at the Konzertsaal of Swiss Radio
DRS in Bern to follow the speech and the demonstrations of Werner
Dabringhaus about the 3-dimensional 2+2+2 Recording® technique.
After a welcome apéro Werner Dabringhaus started with an
explanation of the setup used for the comparison of the 2-dimensional
formats stereo and 5.1 surround with the 3-dimensional 2+2+2 audio
format. 2+2+2 Recording® is the compatible use of the already
existing multichannel transmission medium DVD Audio and SACD. The
3D sound reproduction is provided by an additional pair of speakers,
which can be operated alternatively to the 5.1 centre/subwoofer.
Three complete loudspeaker arrangements had been installed for
this event by Giovanni Dolci of Dynaudio Acoustics and Thomas Wenger
of J+C Intersonic: 5 active Dynaudio AIR-20 plus an active AIR BASE
1 Subwoofer were used for the 5.1 surround and for the stereo setup.
Two additional AIR-6, elevated on stands to a height of half of
the stereo baseline, together with the stereo and the rear pair
formed the setup for the 2+2+2 arrangement. All speakers had been
accurately adjusted and calibrated prior to the session.
Several situations exist in classical music, where the 3rd vertical
dimension is very natural: starting from a slightly elevated position
of a choir in a concert situation, to musicians and choirs on surrounding
galleries in churches and of course, a large organ in a cathedral.
Excellent, mainly classical recordings of his own label had been
selected by Werner Dabringhaus for the demonstrations. Even in the
very reverberant Konzertsaal, which has to be accepted as non-ideal
for monitoring purposes, the differences between the three formats
became easily apparent. Especially the organ demonstration of a
2+2+2 Recording® was very impressive to the audience, as the
vertical dimension became very realistic and the playback reverb
time of the Konzertsaal
was no more determinant related to the reverb time of the recording
itself. But also an outdoor recording of noises in a mountain area
amazed the listeners by its realistic 3-dimensional experience.
Werner Dabringhaus invited the audience to walk around to find the
limits of the very wide sweetspot area. Switching back to 5.1 or
stereo clearly reduced the spatial experience to 2 dimensions.
In contrast to the 5.1 cinema application, 2+2+2 Recording®
has been invented primarily for music applications, but it can solve
several problems introduced by the 5.1 centre speaker. As we all
know, the centre speaker has to be positioned exactly on the same
height and very precisely in half way between the front speakers.
Furthermore, it has to be the same speaker type, since it forms
two stereo pairs in the front. All these requirements can be achieved
in a cinema behind a screen, but are usually a big problem in home
applications, where a non identical centre is placed very often
below the screen. 2+2+2 offers a very superior solution to that
problem: not only it can create a virtual centre speaker, it allows
the localisation of a sound source everywhere on a screen, horizontally
AND vertically. This was demonstrated very impressive, when Werner
Dabringhaus walked in front of the centre speaker and it became
evident, the centre speaker of the 5.1 setup had been switched off
previously and was virtually replaced by the 2+2+2 setup.
This capability can be used for compatible playback of 5.1 recordings
on 2+2+2 speaker arrangements. Check out www.mdg.de for more information
on that topic. High resolution Stereo replay is obtained from the
first two 2+2+2 channels. 2+2+2 Recording® uses the non-compressed,
24-bit multichannel DVD Audio technology for storage and playback.
Werner Dabringhaus emphasised the following points for equipment
evaluation: a multi format player which is able to reproduce DVD
Video/DVD Audio/SACD should be chosen. It must be checked carefully
that the player and amplifier don't limit by mistake the .1 channel
using a low-pass.
As in good old Stereo, a lot of different microphone arrangements
can be used for 2+2+2 recordings. Werner Dabringhaus gave a very
simple example of an arrangement for a 2+2+2 production of an orchestra:
the main stereo mikes basically feed the two front channels (also
used for stereo), the ambient mikes feed the two rear channels and
the elevated stereo spot mikes are mixed to the two additional front-top
channels.
At the end of his lively speech and impressive demonstrations,
Werner Dabringhaus mentioned the importance for 2+2+2 Recording®
that not only classical productions but also contemporary music
has to be distributed on DVD Audio. 2+2+2 offers a lot of interesting
and creative possibilities to the producer and 2+2+2 already got
its own flag for the MLP™ (Meridian Lossless Packing) bit stream
to identify the format.
G. Leutzinger
|
