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Live Recording Techniques
- On a Budget! Several
years ago when Mini Disc (MD) recorders first came out, I thought it would
be neat if musicians and singers could have their own Archival CD Recording
of a live concert that they had invested so much of their time over several
weeks to rehearse for, but never heard from the audience's point of view! So
twenty or so recordings later, I decided to write down the techniques I
use, some of which have been learned through hard experience. The techniques
described here of course do not rival a recording studio with multi tracking
and multiple takes, but focus on how to do a live recording, with no chance
of a re-take, how post processing will let you "polish up" the
final mix, how to make a professional looking product and how to cover your
costs, which includes your recording equipment investments. Step One - The Live Recording Of
course you want to have a high quality live recording, keep your equipment
purchases on a budget, and as portable as possible. An MD recorder can help
to address these requirements, the quality is far better than cassette tape,
and the portable version of the MD recorder is very small, requiring no
AC power. The
most important components in the live recording process are the microphones
and the room acoustics! For classical and jazz performances the room should
have the right amount of natural reverberation to make for a "live"
sound. An acoustically dead room makes for a "dull" live performance
and, although you can add some artificial room reverberation into the final
mix, will never match the "real thing". Selecting
the Digital Recorder The
invention of the MD recorder made live recording an affordable hobby. There
are many types and brands on the market today, but only the portable models
made by Sharp appear to have the right advantages for live recording namely,
a proper recording level meter calibrated in dB, no AGC (a live recording
killer). Another important consideration is that the MD recorder has the
right level of input level compression that prevents the dreaded overload
condition. I set my Sharp MD recorder's recording level once by clicking
my fingers hard right next to the microphones so the recording level just
goes over 0 dB and then leaving it at that setting for the rest of the concert.
Even a large orchestra will not clip the recorded signal (if the mics are
set back at least 15 feet) and the dynamic range is good enough to pick
the quietest vocal soloist! Where do you buy the MD recorder? I got mine at www.minidisco.com My first Sharp lasted for a while until it got kicked off the top tier of a chorus riser, five feet onto a wood floor. Thankfully, it was connected to plenty of microphone cable and finished recording the concert, but its eject mechanism never worked properly after that traumatic experience. This gave me an opportunity to examine the insides; the thing is a marvel of miniaturization.
Sharp
722 MD Recorder - with stereo "T" microphone Selecting the Recording Microphones The
microphones should be the small condenser recording type. These have a flat
response to capture from the lowest bass to the high pitch harmonics of
the female singing voice and also preserve the clarity and position of all
the reverberances in the live room setting. The small size of the condenser
diaphragm allows it to respond quickly to fast sonic attacks. The
other important requirement of a live recording microphone includes the
ability to withstand high pressure levels. It is amazing how loud a large
orchestra can get, especially with percussion and horns! The one thing that
will absolutely spoil your live recording is a mic or recorder overload,
since you can not go back and retake it again. The other most important
parameter is the condenser microphone's self noise. This coupled with the
MD recorder's microphone preamp, always ends up as a slight hiss in your
recording, but modern post-production hiss reduction techniques can reduce
much of this to a very low level. Where do you buy these
microphones on a budget? My favorite vendor is the www.soundprofessionals.com
Web site, which will show the numerous recording microphone options available,
ranging from the single point stereo microphone that is fitted inside the
same box that encloses your Mini Disc recorder to binaural microphones that
fit on top of a microphone stand. You can kit out your microphone requirements
for anything between $80 to $250. I have had some good
success with the single point stereo (in rooms that have natural good acoustics)
but prefer the Binaural type that sit on top of a microphone, spaced the
distance between ones ears. Locating the Microphones Since you are making
a live recording of an entire group of musicians and/or singers, then the
microphone recording location should be far enough away to get the entire
mix of sounds without a single instrument or voice drowning out the rest.
The concert producer should have made the appropriate arrangements for any
sound reinforcement to ensure that the audience hears the right balance,
although on occasions this may not happen - typically a soloist is too quiet
against the accompaniment. Don't worry too much if the balance is not quite
right as there are post processing techniques to address this problem. Every
room, especially large ones, has a sweet spot, where all the sounds reverberate
just right. Walking around the room with headphones fully covering the ears
and a single point stereo microphone plugged into your portable MD recorder
during a rehearsal will help you find the room's sweet spot. If the ideal recording
position is right in the middle of the audience seating area, you have two
options. Either sit in the ideal listening position with the MD recorder
on your knee (and a single point stereo microphone) or put the microphones
high up on a tall pole to clear the audience rustles and coughs. My budget
microphone pole is actually the 1/2" diameter poles from two living
room stands screwed together to clear 7 feet using one of the original light
stands as a base! I then use a 20 foot extension cable bought from the Sound
Professional guys (above) to run to my MD recorder. I don't bother putting
on my headphones (looks geeky, and hard to do while performing!) but just
keep an eye on the MD recorder level meter. Remember also the Sharp MD recorder
input level compression is very good at handling peaks. Step Two - The Post Processing
Mix So
you've got home and listened to the live recording. You should be amazed
at the recorder's stereo clarity, if it is your first time. However there
are some things you can do to "polish up" before burning a CD,
this step is called post processing. Transfer to PC Hardrive The
absolute best way to post process to transfer from the MD player to the
PC over a fiber optic cable. Most portable MD recorders cannot do this.
In my early days I used the recorder's analog output to my sound card's
line input. This would give me a noise floor of about -59 dB, which you
can hear as a very quiet hiss under normal listening levels. Later on I
invested in a Sharp home MD/CD deck with fiber optic output (because it
was on sale for $130) from Minidisco (above).
This drops the noise floor to -90 dB, a very respectable number for
amateur recording. The
second advantage of using a fiber optic cable is that there is no sound
card input gain to adjust. If you are using the analog method, find which
setting avoids any overload of the sound card's analog input. Don't bother
maximizing the sound level track by track, that can be taken care of in
the post-processing mix. Where can you buy a cost
effective sound card with fiber optic inputs? I bought a DiO 2448 for $110 at www.soundprofessionals.com (I
should really get a discount for free advertising!) and run it at the same
time as my SoundBlaster, which is used for output to my studio amps. There are many programs available for transferring
your MD recording to hard drive. One favorite is N-Track Studio, since it
has input VU metering and live monitoring while recording. Another excellent
choice is Total Recorder which is available to download at www.highcriteria.com. The Total Recorder program also
has many other advantages such as being able to simultaneously record to
WAV file any music or sound being played in real time by a software program.
Even
though the MD recorder has editing facilities, don't use them on your precious
live recording MD! One mistake can ruin every thing (if you do, eject the
battery so the recorder cannot write the changes back to the disc). The
easier way is to use the PC program to create a WAV file which a bit extra
at the start and end, you can always trim and fade later in the post mixing
step. The
Post Mix Without a doubt, the absolute best program for post-processing live recording WAV files is Syntrillium's Cool Edit Pro. It is worth every penny of its $399 price. The DEMO version lets you do anything but save for 30 minutes. Failing that Cool Edit 2000 1.1 (with preview) for $69 from the same company is a good alternate.
Cool
Edit Pro's Effects Menu The post-processing sequence (described in detail
later) is as follows, with some steps avoided for certain recordings. 1.
Remove "bad" sound artifacts 2. Tone down any overbearing voices or instruments 3. Use
dynamic processing for a better balance between instruments and voices 4. Apply
any extra room reverb 5. Rebalance left and right to widen or narrow the
stereo image 6. Normalize the maximum sound level to about 85%
of maximum. 7. Trim
the start and end of the track. 8.
Save the new file as a separate file from the original RULE
#1 - Your ears can easily get used to overdone effects. Too much filtering
can "dull" the sound, too much reverb makes for unnatural echo,
too much compression can give the sound a "squeezed" feel. Take
frequent breaks and go back to the original MD track to reset your ears
to the original recording. RULE
#2 - Filtering effects should first be used to REMOVE unwanted information
rather than boost other parts 1) Remove Sound Artifacts Sound
artifacts are basically impairments ending up in the live recording. The
Minidisc's ADTRAC compression process adds some very slight high frequency
scratching around 8.7 kHz when the music program has a lot of sonic energy
(e.g.. a majestic church organ). To eliminate this artifact, you use the
sound editor's parametric equalizer to create a narrow -12dB notch (Q =
18). Sweep the filter to find exactly where the artifact is and click the
filter in and out in preview mode to make sure you are not compromising
the recording. Once the preset has been saved, just use it for every MD
track. Cool
Edit Pro has a good Hiss Reduction effect. If possible, select a short portion
of a recording with no music and adjust just enough to lower to an acceptable
level. Listen carefully to other parts of the track to verify no dullness
or warble has been added by Hiss Reduction. Cool Edit Pro remembers the
Hiss Reduction setting for subsequent tracks. 2) Tone
down any overbearing voices or instruments Sometimes
the level of bass or percussion can be a little overbearing. I normally
use the Parametric Equalizer to adjust the levels, because it is easy to
click a specific filter in and out. Be careful with how much high frequency
you tone down since this can also remove the live feel to a recording. 3) Apply dynamics processing to achieve better balance between
instruments and voices Cool
Edit Pro has an excellent Dynamics Processing effect. With some careful
compression you can "pull" out a quiet solo voice against much
louder accompaniment. 4) Apply any extra room reverb Normally
you don't need to do this step, but in the case of organ recitals you can
make the organ appear as though it was in a magnificent cathedral. If the
live performance was in a "dull" room, you can add some artificial
room reverb, but do it carefully and double check on headphones and studio
monitors that it doesn't sound phoney! 5) Rebalance left and right to widen or narrow the stereo image You
can use this step to create a more rounded sound for large choruses. Compare
between headphones and studio monitors to ensure you haven't made the image
too wide or turned it into mono! 6) Normalize the maximum sound level There's
nothing more annoying when you listen to your finished CD then to find that
one track is much louder or softer than the rest. Normalize every track
85% of maximum. Why 85%? It's because some (cheap) CD players can not handle
dynamic sonic "bangs" very well. 7) Trim the start and end of the track Cool
Edit Pro allows you to zoom into the start of the WAV file. Highlight the
section before the music program starts and delete. Go to the end of the
track and highlight 3 to 5 seconds. Use the Envelope effect to taper down
to zero by listening to the preview to hear the effect of the decay. Now save your work as a new WAV file! Step Three - CD production Once
all your WAV files have been processed, you are ready to make the CD. Remember
that this article is focused on how to make an Archival CD Recording of
live performances for the benefit of furthering the education of the performers.
It is illegal to make CDs for commercial sale without the permission of
the copyright holders. That said, there's no
reason not to make your CD recording look professional. There are several
vendors of CD labeling products, including AVERY who are carried by the
likes of OfficeMax. Make sure you clearly indicate on the CD label and jewel
case cover that this is an Archival Recording - not for commercial sale.
A charge of about $6 will be sufficient to cover your expenses, offset some
of the costs of wear and tear on your equipment and go towards some of the
expense in purchasing the recording equipment in the first place. Conclusion Well that's about it!
I have always been surprised at how many performers appreciated being able
to hear themselves as the audience does. It has helped them improve their
styles and, for amateurs, gives them another reason to participate in performing
live music. I get comments from people who say they still play their Archival
CD Recordings years later or when they are a little down. Performing live
music makes a nice contrast to the "spoon feeding" of TV and movie
theatre commercialism, enough said! David Breton is a degreed software engineer with experience
in audio and video processing. He is a participant in performing live vocal
music and a strong supporter of community-based performing arts. He lives
in the Newport, Rhode Island area and can be contacted at dbretonusa@yahoo.com. Copyright David Breton 2001
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