HIDDEN ASSET OF FIGURE OF EIGHT MICS
to the inherent front to back ‘out of phase’
lobes of a figure of eight microphone, there is an
‘angle of placing’ advantage, in choosing to
use a figure of eight mic in some circumstances.
There is a ‘unique null’ between the two
lobes, due to their inherent opposite phase.
the mic can often be placed to favour some
instruments and very effectively have the null
avoiding the pickup of direct sound from
instruments immediately below, or to the sides.
For instance, over a choir at the back of an
orchestra, and similarly where you have certain
percussion instruments at the back of an orchestra
and some focus is needed, without the upwards
pointing euphoniums and tubas being added to the
writer finds that there is a further advantage in
these circumstances, in that the rear lobe of the
figure of eight adds to the ambience pickup from
the focussed area, which is opposite to what a
cardioid mic at the same spot, would be able to
can sometimes be useful to use a figure of eight
for a soloist out in front of an orchestra or a
smaller ensemble. Without going in too close, you
can often avoid getting too much pickup from the
wider range of performers, to the sides of the
GUN MIC USES
writer has this thing about ‘gobbing’
microphones in vocal situations. When overdubbing
vocals to backing tracks, an Audio Technica 4073a
short shot gun mic (Pic.
One) is used for the vocalist. Set
up around 12 inches from the singer, the capsule
is obviously a little further away. You get a more
natural sound than using the usual vocal cardioid
right up close to the lips.
usual variations in levels, with mic to mouth
uses, do not occur, as the amount of change is
such a small ratio of the distance to the shot gun’s
capsule. However, an excellent Yamaha GC2020
compressor limiter is still used to ensure that
the vocals do sit properly in the mix!
it doesn’t end there. In the field of location
Classical music recording, AT 4073a or their
longer AT4071a shotguns are regularly used (Pic.
Interestingly the interference tube slots on these
AT shotgun mics are not universally around the
mics body. That then appears to be useful to angle
them to make use of an apparent reduction of HF
pickup from where the slots are.
writer’s M&S activities have regularly
involved the use of the shorter AT shotgun
mentioned, as the Mid mic. It has certainly made
it much easier to record duos, trios &
quartets in the Wigmore Hall for instance, by just
using the in-house height adjustable mic sling
arrangement over the front row of the seats! In
later times a Schoeps CMIT5U short shotgun had been
used as the Mid mic (Pic.
Three), with its greater uniformity
of directionality, in the upper part of the audio
recording sessions for CD release with soloists
involved with ensembles or orchestras, there is a
lot to be said for having the vocal soloists agree
to face the rest of the performers, from behind
the conductor. With more than one soloist you
space them apart and use separate shotguns at a
distance of around 1.5 metres. The object is to be
able to appropriately pan them and continually be
able to balance them individually against the rest
of the performers
instance, at some Psappha sessions for a CD of ‘Mr
Emmet Takes a Walk’ by Sir Peter Maxwell Davis,
the three vital soloists were separately miked
with AT4073a shotguns. The row of singers were
facing the instrumentalists, around five metres
back from behind the main M&S pair and the
conductor, and able to see his arm waving!
‘psappha.com’ website has a ‘Watch &
Listen’ section with two Video-ed Concerts in
which the writer provided the mixed sound feeds to
one of the camera’s operated by the Lancaster
University team. There is ‘Trouble in Tahiti’
and ‘Light House’.
latter one features a high tower, from where the
singer soloists mainly performed. Sometimes the
four AT shotgun mics can be seen ‘in shot!’.
The shorter pair were aimed at the base area and
the longer versions pointed up to the top of the
tower. The voice balance and perspective seems to
suit the sound from the un-miked Ensemble at the
back of the stage, at this Lancaster University
Concert Hall performance.
you have a wide orchestral layout, or a wide
choir, not in the preferred semi-circle where a
single pair would suit, or you are recording a
wide staged drama production, try the use of two
spaced apart M&S pairs of mics!
have them at around 1/3rd and 2/3rd spacings along
the front of the performance area. The crucial
thing is that you angle them inwards to the front
centre of the layout. For instance, with an
orchestra or choir, you angle both pairs inwards
symmetrically something like 10 to 30 degrees
depending on the situation and how far back the
pairs need to be.
pointing them straight ahead would not work! What
you get with this technique is the left half of
the soundstage covered by the left output of the
left pair and right half of the soundstage covered
by the right output of the right pair. The
ambience from behind the mic positions is also
pairs are conventionally decoded and mixed
together. The Mid mic polar patterns probably need
to be cardioid, soft cardioid or omni, as
appropriate to venue characteristics. Soloists
beside the conductor have been satisfactorily
covered, however spot Shot Gun mics with are not
ruled out! Possibly it can be helpful if the
spaced out M&S pairs are moved a little in
their positioning to result in a more appropriate
near central placing of a front stage soloist’s
M&S pairs have been used for sound feeds to
camera for Black Swan Film & Video excellently
filmed for DVDs of the National Children’s
Orchestra concerts. It actually suits the visuals
to not have a mic stand behind the conductor,
albeit that the writers mic stands are still ‘annoyingly’
shiny silver and not non-reflective black!
stages are two restricted in space to get a mic
stand directly behind the conductor, and slinging
from above can be a nightmare! Covered in Paper
No.2 is the hidden bonus available from this use
of spaced apart pairs of M&S rigs, as it does
also allow for 5.0 Surround play back! – see the
comments in the earlier Paper
PIN XLR CONNECTORS
writer has always made use of one cable for each
stereo pair of mics in his inventory. So much
easier to run just a single cable to the recorder,
especially with the use of a M&S stereo pair.
There is less chance of getting the Mid and Side
feeds inverted, as on one occasion, for some
amazing reason, and the writer did and not
actually noticing it! None of us are infallible!
screened, four core cabling is used with the
essential use of the correct pair of wires in the
twisted four, being chosen for each of the mics. A
totally unacceptable amount of cross talk occurs,
if the proper selection is not made.
use the opposite pair of wires in the quad of
four, for each of the mic feeds. The writer has
not used what is specifically called a ‘Star
Quad’ cable, and doesn’t seem to have found it
to be really necessary, so far!
NARROW CROSSED PAIR RECORDINGS
is a processing system which can offer a stereo
widening facility for a stereo feed, especially
where a narrowness is noticed with closely spaced
stereo pairs. The basis of it is to make use of
the in-phase (Sum) and out-of-phase (Difference)
components in the stereo they produce.
writer noticed this when using a set of three shot
gun mics to reach the back of the local Woburn
Sands Band, which were augmented by a not very
wide angled pair of cardioids in the same rig,
pointing down at the front of the band. The rig
was suspended over the front of the audience in MK’s
an well known old process, first of all obtaining
the Sum and Difference signals from the initial
‘stereo’ obtained, and then treating it in the
same way you decode the feeds from an M&S pair
of mics! This way you have the ability to increase
the stereo width you originally obtained.
the writer’s case all five mics at the concert
were mixed down to stereo at the concert. Possibly
a greater choice might have been available had the
five mics been separately recorded, in that the
down ward facing pair of Sennheiser MKH40 mics,
would be separately dealt with.
panned mix of the three shotguns pointing towards
the rear of the band, particularly for the
soloists placed either stage right of left at the
raised area occupied by the bands percussion
section. Then the feeds, from the three
rear-of-band facing long AT shotguns could have
their mixed feed widened separately.
the event dealing with the concert mix down
obtained on the day did enhance the stereo result
to the satisfaction of the Band members and
especially that of Brass Band Conductor, Arranger
and Composer, Len Jenkins, I am told
STAND ISOLATION FROM WOOD FLOORS
solid concrete floors or on the hard stone floors
of older Churches, you don’t have a problem with
mic stands relaying vibrations up the stand to
sensitive microphones. There are numerous
isolation mounts available for use in the Film and
TV sound capture areas, but the writer has always
used a means of initially isolating the mass of
the mic stand from where its stands on many wooden
blocks of thick foam around at least seven inches
square and two inches thick, with a central recess
cut in it for the foot of the mic stand involved,
are used in the writer’s case. The mass of the
stand really isolates the mics at its top from
floor induced vibrations. Many of the direct shock
mount isolating mounts rely on the weight of the
mics used and also there is usually a
communication of the vibrations from the stand by
the mic cabling itself.
concert situations the foam blocks can be taped
around their sides to physically relate them to
the floor. If the audience seating arrangements
use individually placed seating, as opposed to
fixed pews in many churches, a space can be
created around the mic stand area.
are ‘Line Source’ loudspeakers for PA use,
where the vertical column array of transducers
produces a wide horizontal spread of sound out
towards the listening audience, with a significant
reduction from above and below the direct feed,
avoiding reflections from floors and ceilings.
now imagine a microphone with a number of capsules
in a column, which you use vertically and get a
wide horizontal range of sound acquisition, with a
very useful reduction of room sound from ceilings
do exist and the writer knows of two such
products. There is a Microtech Gefell KEM970 and a
Pearl ELM, which the writer used a number of years
ago. The Microtech Gefell uses eight cardioid
capsules in its vertical column. The Pearl mic
used their ‘unique’ rectangular cardioid
capsules for its vertical line of capsules.
assumed use is that these microphone arrays are
just used in situations where you need to get a
coverage from a wide layout of contributions from
public speakers at conferences, etc. However the
writer did use the Pearl product, very
successfully in a M&S rig for three singers in
a room, where it was essential to really reduce
the pickup from the reflections from the room’s
floor and ceiling. Another useful addition to
possible recording techniques, for your thinking
was a school recording situation where a small
choir of eight children, needed to be recorded
singing to backing tracks. On another unrelated
occasion, two soprano singers had backing tracks
to be used for a demo recording.
for the first case, eight headphones were not
available, apart from the Health & Safety
aspect of having the performers tripping over the
leads! So with the children in a semi circle in
front of a M&S pair in a large room at their
school, two small Dyer Cube powered speakers were
placed together under the raised up mics.
covered at the start of this paper, an asset of
the figure of eight mic is the ‘null’, between
the inherently ‘out of phase’ sound pickup
lobes. So the close together speakers, placed
below the mics, will be greatly ignored by the
Side figure of eight and similarly by the use of a
figure of eight Mid mic. In both of the writer’s
sessions, it wasn’t necessary to go as far as
using a Mid figure of eight, as the cardioid in
use acquired the voice level balance adequately.
four channels on an Edirol R44 recorder (Pic.
at the sessions, to separately recorded the
decoded M&S mic feeds on tracks 1 & 2,
with the stereo backing track feeds put down raw
on to tracks 3 & 4, for post production mixing
later church recording for the two sopranos with
their backing tracks, the same setup and post
production mixings were used, the standing
distance from the mics determining the amount of
overall ambience capture from the church acoustic.
A degree of stereo church ambience also became
added to the backing track, with the speakers
angled outwards, the final backing track balance
determined by the later mixing in for the raw
feeds on 3 & 4 with the mainly voice feeds on
1 & 2.
IN YOUR EARS
can be occasions when you are asked to record in a
situation where there is no choice but to be
seated in the audience! Depending on if you can
get a suitable sited seat and hopefully have no
one bored and snoring near to you, apart from the
nearby clapping definitely being unlikely
controllable in level, you can operate in Binaural
mode with a pair of electret mics in, or
immediately near your ears, and powered by the
Plug In power facility in SD recorders like the
Olympus LS10 (Pic.
ago in the early Mini Disc days the writer used a
pair of DPA4060 electrets mounted on a fold up
head band originally made for ear phones. The ear
phone units were removed and the same cabling used
to feed the mics, unbalanced of course, to the
recorder. These were the Sharp MDs which unusually
have manual mic input control, unlike a certain
other well known make!
DIY box was made to hold the recorder on one’s
knees, so that the metering could be easily seen
and levels adjusted. To avoid any chance of the 3
pin mini jack input being moved, its input went to
the back of the box to allow the use of a 3 pin
‘mini XLR’ socket, for the mic’s cable
fitted with the male version.
Olympus LS10 has now taken over this Binaural
Stereo capture with a similar DIY box which also
has a built-in battery powered headphone feed for
subsequent listening. The low outputs of these
recorders do not directly suit a couple of
Sennheiser HD650 headphones used to judge the
result in the concert interval. Great also to
impress audience members during the interval!
DPA mics, on the headband, are not fully in one’s
ears, but the other mics the writer has also used
are the Soundman OKM-11 pair of electrets, which
do fit in ones ears, as they are inside some
suitably shaped comfortable foam. The trick is to
bring each cable feed out in front of your ears
and go back over the top of the ears, and then
down to the recorder. This greatly reduces the
chance of having the mics ‘pop’ out from one’s
a concert where different performers had to take
up various different positions you find you have a
built-in facility, with the use of in-ear mics.
You become a seated ‘mic stand’ which can be
silently turned towards the changed sound source
to balance the stereo acquired!
word Binaural was used earlier, as the recordings
do particularly suit listening on headphones.
However loudspeaker playback is not seriously
upset, especially if you angle the speakers
inwards and then go and sit more in between them.
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