writer has used a number of microphone rigs for
5.0 Surround in a variety of different acoustic
spaces, and even out in the country side! There is
a point of view that, as the human head’s
hearing system is quite ‘coincident’, compared
to the size of the sound sources in the acoustics
we capture, is it not best to have a ‘coincident’
set of microphones to start with, and then the
spaced out loudspeaker playback reproduction feeds
what is captured, back to the ‘coincident’
human head hearing system.
having been the user of many different coincident
Mid & Side mic rigs, over many years, it has
been very easy to expand their use into the
capture of 5.0 ‘Horizontal’ Surround, and then
beyond! What ever rig is being used, it will be
mixed ‘on the day’ for the Stereo, as one is
usually being paid to be there for that!
the Surround, the mic feeds post the mics amps,
are separately captured ‘raw’ on four or eight
channel recorders. An Edirol R4 Pro (Pic.
One), an Edirol R44 (Pic.
Two), or for up to eight channels, a Deva 5 and
lately a Sound Devices 788T are involved, for the
later Mastering for the Surround listening
the term 5.0 Surround, forget the 5.1 use of a
special LFE Sub feed, for the Low Frequency
Effects used in Film & TV. Any sub used for a
recordings made in acoustic spaces, will just be
involved in getting a fuller low frequency range
from the Surround’s front L and R loudspeakers.
HISTORIC W,X,Y,(Z) SYSTEM
unique SoundField microphone has been around for
many years and continues onwards. Apart from its
early use as a Stereo microphone, there was also
the early Surround system called Ambisonics and
also Periphony, adding height to the horizontal
Ambisonics surround. Now with 5.0 (or 5.1
Surround), the SoundField mic is right in there. (Pic.
W,X,Y,Z refers to the four B Format signals, that
are cleverly created from four A Format signals
provided by the tetrahedral array of four soft
cardioid capsules inside the microphone body. You
have an omni and three figure of eights, very
coincident and symmetrical. W is the omni, X the
fig. 8 front to back, Y the fig. 8 side to side
and Z the fig. 8 up and down.
Horizontal Surround, the three W, X & Y
signals can create a forward facing cardioid with
W and X, and a rear facing cardioid with the W and
a phase inverted X. Appropriately using Double
M&S decoding (also known as MSM) you get the L
& R Front Surround, Ls & Rs Rear Surround
and use of the forward cardioid for the Centre
W, X, Y, RIGS
Four shows the use of three Schoeps CCM mics. There
is a CCM2 omni (W) between a CCM8 front to back
(X) and another CCM8 as the side facing Y. Pic.
Five has a DPA 4006TL omni (W) between a
Sennheiser MKH30 front to back (X) and another
MKH30 side to side (Y). See Close-up (Pic.
in the SoundField mic case above, initial mixing
of the Omni and the Figure of Eights is needed to
get the necessary forward and rear facing
Cardioids. Especially with the CCM mics you have
to allow for the different output levels of the
CCM2 and the CCM8s. The DPA/Sennheiser rig levels
are quite closely related. Using the Double
M&S decoding covered earlier, you create the
Front L & R Front, the Rear Ls and Rs with the
forward facing Cardioid for the Centre.
DOUBLE M&S RIGS
physical cardioid mics directly involved, you
avoid the need to mix an omni and a forward facing
figure of eight to derive the two cardioids. Any
level differences, with different makes of mics,
are more easily handled, as they will just
directly affect the front and rear widths produced
in the Double M&S decoding.
Seven has the dual cardioid capsule MKH800 Twin and
a MKH30 figure of eight for its Double M&S
Eight involves a four rectangular
capsule Pearl DS60 microphone. The microphone is
orientated so that two of the capsules face front
to back and the other two side to side. The two
side to side pair of cardioids need to be mixed
together initially, with the right hand facing one
phase inverted, to create a figure of eight for
the Double M&S decoding, using the front to
back other pair of cardioids.
FROM SPACED M&S PAIRS OF MICS
slight drift from ‘true coincident’ miking, a
useful ‘specialist’ stereo miking system, is
the use of two spaced apart M&S pairs of mics.
Suppose you have a medium to large choir, and they
cannot be arranged in a suitable semi circle for
the use of a single stereo pair of mics, there is
an alternative, which can also be used for 5.0
the stereo you arrange the pair at around one
third spacing in front of the straight line of the
choir, at a distance suitable to the acoustics and
balance etc. Very importantly, you angle each pair
inwards to point at the front centre of the width
of the choir.
the stereo, both pairs are decoded in the usual
way, and the decoded signals mixed directly
together. The variable width, available in each
pair, needs to be appropriately set. The left hand
pick up of the left hand placed pair, along with
the right hand pick up of right hand place pair,
will reproduce the choir’s stereo delivery very
evenly across the soundstage, far better than
having many pan potted mics spread across the
front of the choir.
bonus is that 5.0 Surround is available! With the
four laid down raw signals you can separately
decode them and then assign them to the Surround
feeds as follows. Feed the left of left placed
pair to the Front Left, the right of the right
placed pair to the Front Right, then there are a
couple of alternative ways of feeding the Rear Ls
to the necessary angling in to the centre front of
the choir, you could perhaps choose the right of
the left place pair for the Rear Rs and then the
left of the right place pair for the Rear Ls. The
opposite of that could be tried and a decision as
to the best made! The Centre feed is obtained by
summing the two Mid mics of the rigs, as they are
conveniently pointing at the Centre of the choir.
USE OF SURROUND MIC RIGS
are three Surround mic rigs possible using Omni
mics, which do have so very little handling and
wind noise interference compared to directional
mics, especially figure of eights. Also, they are
so easily wind-shielded, that it is not really
worth trying any of the other rigs discussed,
except the SoundField with its soft cardioids, and
which can also be successfully wind shielded.
is the Canadian Holophone with five omnis as an
ellipsoidal array . There is also a LFE feed,
derived internally. Windshielding is available for
Nine is of a DIY creation which is based on a Dummy
Head for stereo use, with flush mounted Schoeps
CCM2 omnis. Obviously Binaural Stereo listening on
headphones comes in mind, as well as for
loudspeaker Stereo, using just the front L & R
stereo with loudspeaker playback works very well.
This is mainly by making sure the two mics in use
do ‘see’ the centre soundstage by tapering and
curving the surface, compared to having them just
pointing out to each side of the head, as is done
on early commercial Dummy Heads.
addition of three more omnis for the Surround
effectively takes things forward. The Rear CCM2
mics are at the back of the head, with the Centre
one at the front, between the L and R main mics.
Effective windshielding using flour sieves and
ladies tights was also created. Pic.
Eleven is of the recently introduced DPA 5100
Surround Microphone. This is a novel lightweight,
thoroughly wind shielded unit with no handling
problems. Five omni mics are in the expected
places. The front L, C & R are made a little
directional, by short Interference Tubes, with the
mic capsules actually very coincidently placed
towards the internal rear of the unit. The Ls and
Rs capsules are flush mounted at the rear of the
unit. There is a LFE output available, derived
from all the mics.
from capturing Surround in acoustic spaces, the
writer has used the DPA5100 for some outdoor Brass
Band recordings at Village Fetes. The mix down to
stereo for CD use is very good indeed – with the
Centre and Rears reduced in level to that mix. The
5.0 Surround results have really impressed a
number of listeners and certainly adds ‘realism’
compared to the stereo version.
is an addition to horizontal Surround possible
with some of the rigs mentioned. In lots of
recording spaces like churches, the live Surround
effect is not only in a horizontal plane. Also,
fireworks and aircraft display recordings are
surely missing something. Paper No.4 will cover
the capture of the Missing Height in Surround
recording, with additions to some of the above
rigs and the practical way of reproducing it.