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Acoustic Sound Advice
- By Andy J
- Published 05/27/2009
- Recording and Engineering
- Unrated
Andy J
Andy J - Music Business
Andy Gathers Industry related information and passes it on to you. If you have any questions related to the business of music, please send questions to Andy's Article or email andy@crunkbox.com profile.
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Basic information for beginners on setting up various acoustic instruments and tips on balancing the sound for live performance. This does not cover all the technical factors of doing sound which can be found in some of the many articles that are provided in the Electric Blues Club Sound Engineering Articles.
Acoustic music is usually performed without any amplification
(thats why it's called acoustic!), however, if you intend to amplify
acoustic instruments and voice, here are some suggestions on how place
the mic's and get a decent live sound mix.
Presuming you have set up the P.A. system and taken the time to learn about your systems capabilities, the next step is learning how to position the microphones for acoustic instruments and voice.
All the microphones you need should be plugged in and placed in
stands. Singers who also play an instrument should use a 'Boom Mike'
which can be adjusted to allow freedom of movement for the instrument
to be played.
The main volume level should be set about 1/4 way up the
dial. It is important that the vocals are well up in the mix, so start
with a vocal level, set the individual volume control to a level where
the voice can be clearly heard without distortion or feedback, for a
100 - 300w system this would be about 1/2 to 1/4 way up the dial
respectively although systems differ. These settings are purely for the
purposes of starting the sound check - not the final settings.
There are several ways to mic up for acoustic performance
depending on the size of the venue and how much you want to separate
the overall sound.
Accappella
The amount of microphones you need may be dictated by the size of your group. If there are 6 - 10 singers you can get away with 2 or 3 mikes positioned at the front of the stage. One at each side should be slightly directed towards the group with the third positioned to the center. (Two mic's can be used but need to be placed further to the center of the stage). Be careful not to place/point the microphones towards the speakers or any monitors as this can cause a high pitched sound called 'Feedback'. If this occurs turn down the main volume and move the microphones into a better position. (You may have to re-adjust the individual mic's volumes from scratch and keep the main volume at a lower level if this keeps occuring).
The singers need to place themselves for optimum effect,
crowding round the microphones will not allow for the overall sound to
be projected effectively. Stand back from the mic's, aligning in a U
shape or tiered like a choir. How this sounds will depend on where the
strongest singers are placed and the sound you are aiming for, play
around with different positionings until you get the right effect.
Alternatively each singer can use a separate microphone, this
is fine for one - five singers, but an engineer who can keep a track of
the volumes and adjust each mic for you throughout the performance
should be employed. Yes you could set up the sound beforehand and hope
it's O.K. but it can be a nightmare trying to do your own engineering
and performing at the same time. You have no way to monitor the sound
from the speakers effectively, unless you intend to use a radio mic and
wander round the audience then make any ongoing adjustments that may be
required (Not for the faint-hearted or inexperienced
performer/engineer!).
Instruments
In larger sized venues the instruments to be used will need to be provided with separate microphones (unless they are fitted with their own 'pick ups'). Stringed instruments like acoustic guitars tend to work well when a microphone is directed towards the soundhole of the instrument. Percussion instruments like Bongo's, Congo's etc., require the microphone to be above the area of the skins and angled so that it does not hamper the musicians playing. Microphones for wind and brass instruments are set at a height that is allows the musician to utilise the instruments natural projective bell or sound holes.
Set up the volumes to each individual channel and keep the
mains volume down. This will allow the full range of each instrument to
be present in the mix. Acoustic instruments tend to be very prevelant
in the midrange. Keep the mid and treble frequencies low and vary the
bass frequencies on stringed instruments of similar register value like
guitar and violin. This helps to separate the instruments.
In most cases compression and effects are unnecessary, but if
required use sparingly and adjust the controls using the minimum
settings. Effects if overused causes loss of dynamics and seperation
which can ruin the overall sound. Always make small adjustments to any
EQ and volumes - it's easier to turn them up again that it is to lower
them and retain the right mix. This includes the use of reverb or delay
for solo instruments and voices.
It is essential that the vocals are heard above the played
instruments, the vocal microphones volume should be set up to allow
clarity without feedback, which should be avoided at all times.
Microphones should be left on between songs to allow interaction
between performers and audience, but any effects will need to be muted
when a performer is speaking. If you are a solo artist there are 'foot
pedals' and 'switcher boxes' that allow the performer to turn any
effects 'on' or 'off' remotely without resorting to fiddling with the
mixers dials between songs.
If monitors are being used, their set up should be left until
the mains have been taken care of. This can help to reduce the effects
of the delay in the house bounceback but care needs to be taken to
place them in a manner that allows the performers to hear themselves
whilst avoiding feedback.
During the sound check it is important to walk away from the
desk and listen to the overall sound from an audiences perspective. It
is unlikely that you will get it right first time and in venues that
have unusual shapes or pillars scattered around the room, there is
bound to be some loss of clarity or 'dead' areas. Adjusting the treble
or midrange slightly can compensate somewhat but care should be taken
to avoid the overall mix from sounding tinny or muddy.
Take time to get the sound right, arrive at the venue early
and if possible set up and sound check when you are unlikely to be
disturbed by the audience.
Online Equipment Retailers who sell, hire and/or install P.A. Systems, Lighting Systems etc. available in the P.A. & Equiment Hire Companies listings. Visit the Musician Store
to browse microphones, cables, instruments, tuners, effects and other
equipment accessories online. P.A. & Speaker manufacturing
companies listings are available at Electric Blues Club Equipment Pro-Audio section.
Related Articles
These are just a small example of the extensive links to online exercises and lessons we have available in the Sound Engineering Articles section at the Electric Blues Club, which contains links to the page (when not a framed site) plus answers to pretty much everything a beginner, intermediate, advanced singer or teacher needs to know about sound engineering and recording! (All links below open in a new window).
Scott's PA System Tutorial
Explainations
in layman's terms on how to hook up and use a variety of different PA
system configurations with diagrams and directions on hooking things up
from the smallest one-microphone one-speaker system up to a large
stereo tri-amped system plus advice on how to operate the system, tips
and tricks, glossary of terms and active messageboard.
The Speech Inteligibility Calculator
is
a rather cool online educational tool that will calculate reverb time,
critical distance, and expected %ALCONS for the room you input. The
results show the inter-relationship between reverberation time, room
finishes, speaker selection and speech intelligibility. Other online
calculaters by the guys at Mc2 System Design Group include, Javascript
Decibel Calculators, Speaker Q Calculator, Quickie 2kHz reverb time
Calculator, %ALCONS Calculator, Critical Distance Calculator, XGA Image
Size Calculator, Wavelength Calculator, Room Mode Calculator, Ohm's Law
Calculators and a Contractor Prequalification Test.
UnpluggedSound
contains
neat articles and information on Acoustic Sound Reinforcement and audio
engineering by Anton Niedersteiner including general PA operating tips,
Kamloops resources, offline references, links n more.





