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User Name :
RealJustice
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Country : UNITED STATES OF AMERICA |
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State : OH |
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Member Since : 8/5/2007 1:20:53 PM |
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Recording Fundamentals – A Vocalist Perspective
As a vocalist, I’ve found there are many ways to record or “track” vocals.
Choosing hardware can prove to be a daunting task since so many options are
available. It’s good to be prepared
when making a final selection. Having
some basic knowledge of audio, and the different types of hardware will help so
that you can understand your local pro audio salesman.
If you are using the internet to make purchases you need to have as much
knowledge as possible to avoid returns, if returns are an option.
Audio Basics:
It’s easy to visualize a speaker since the grill covering a speaker is typically
removable. Speakers produce sound be
vibrating in place, faster vibrations create higher frequencies which can in turn
be heard. Human hearing has a range
from 20 Hertz to 20 thousand Hertz.
This means that the typical person can hear a speaker vibrate anywhere from 20 times
a second (20 Hz) to 20 thousand times a second (20kHz).
A microphone is basically a speaker in reverse.
Instead of converting energy into sound vibrations, a small speaker, also
known as a diaphragm converts sound into energy which can in turn be amplified and
recorded. When selecting a microphone,
it is important to look for one that covers the frequency range needed.
It is also important to find a microphone that has a good frequency response
curve. This curve is established through
actual experimentation and is generally published by a manufacturer on their website,
or distributed with the microphone as included documentation.
When comparing potential microphones, it is best to look at the frequency
response curve for each candidate and choose the microphone that has the “flattest”
response. A flat response is one where
the sound, measured in decibels is equal in value at every given frequency. Deviations from a perfectly flat curve
can be compensated later through equalization.
When recording vocals, it is typically best to find a microphone with the
flattest frequency response curve possible
Hardware Basics:
When choosing recording equipment it is important to have a fundamental understanding
of both sample rate and bit depth.
In today’s age, almost every piece of recording gear is digital in nature.
This means that any sound that is recorded is recorded discretely.
The most common type of recording is “CD quality”.
When recording at CD quality, sound is captured 44.1 thousand times a second
with a bit depth of 16. This means
that the amplitude, or volume level of the captured sound can be recorded or sampled
in any one of 2^16 or 65,536 locations.
Hardware dictates the level of bit depth that is available.
Any typical sound card for a computer will record at CD quality.
Most musicians elect to purchase additional hardware which allows for both,
greater bit depth and higher sample rates.
The next highest bit depth is 24 which allows for 2^24 or 16,777,216 possible storage
locations. Upgrading to better hardware
approximates the captured sound much more accurately.
The sample rate is another concern and is generally specified as kHz, which
means one thousand times per second.
When listening to a CD, you are listening to music that has been sampled, or recorded
at 44.1 kHz. Upgrading hardware allows
for higher sample rates such as 48, 96, or 192 kHz which in turn increases the quality
of the recorded sound by sampling many more points of the audio wave.
When recording with better hardware you will almost always down mix back
to CD quality. It is important to realize
that down mixing higher sample rate, greater bit depth recordings, always
results in a more accurate final track.
The only down side to using high bit rates and increased frequencies is the larger
file size of each recording. This concern
is fading from view since most new computers and recoding stations come coupled
with hundreds of gigs if not terabytes of storage.
Choosing a Microphone
As a musician you may choose to use different microphones for different purposes. It may not always be necessary to record
studio quality tracks. When I’m working
out a new melody or have a stream of lyrics come to me, I’ll take my cell phone
from my belt and start recording my ideas.
I’ve chosen a phone that has a button that when held starts recording, granted the
quality is poor but it’s the perfect tool to help me “remember” my ideas.
Both digital and tape handheld recorders offer a similar convenience.
The iPod revolution has also introduced an unlikely friend.
Last year Belkin introduced an add-on to 5th generation ipods
and 2nd gen nanos. It’s
called the TuneTalk Stereo and retails for $69.
This add-on is about the size of a book of matches and includes two high
quality microphones. This external
interface allows CD quality, stereo recording on the fly.
This is a great addition to any ipod.
I take the TuneTalk everywhere I take my ipod.
The uses are limitless; I’ve used the device to record live CD quality sessions
with other players, it has an input with an autogain feature that I’ve used to record
the outputs of mixing consoles. I’ve
also used it to track the primary vocals for a song when I found out I couldn’t
replicate the sound with any other studio gear.
The only drawback to this device is that there is no headphone output so
there is no way to monitor the output.
For the vocalist, microphones come in two different flavors, condenser and dynamic. Dynamic microphones are usually used
by stage performers. They typically
have smaller diaphragms and are less sensitive.
Condenser mics usually live in studios, have large diaphragms, and as a result
are very sensitive. When using a condenser
mic your recording environment must be quiet.
If you’re serious about recording at home or want to build your own studio then
a condenser mic is the way to go. Condenser
microphones require a power source, this 48 V source is referred to as “Phantom
Power” and is included in some pieces of recording gear.
A few mics exists with integrated power but most require an external source. I use an external box known as a Tube
Pre which has a built in power source.
The Tube Pre powers my condenser mic using the same XLR cable that carries in the
sound. The Tube Pre also provides amplification
using an analog tube to warm and fatten the resultant signal.
Pass though boxes also exist which have the sole function of returning power
to the microphone. Stand alone phantom
power boxes can be acquired for less than $20.
Choosing a microphone can be a difficult experience since laws exist in the
US
barring the return of microphones.
By law, music stores are not supposed to let you try any of the display models. Through experience, you may find favor
in a certain manufacturer. I’ve been
using an AKG performance mic and with a tight budget purchased the new condenser
AKG Perception 200. For $149, it has
performed beautifully. There are a host of great mics that fall into any budget. I would suggest reading as many reviews
as possible prior to making a purchase.
Look for flat frequency response curves that spread from 20Hz to 20kHz.
Many mics offer selectable polar patterns.
Polar patterns represent a microphones physical region of sensitivity. A cardioid pattern is generally best
for a single vocalist, if you also want to mic an instrument or larger group of
singers then a microphone with selectable patterns may be the best choice.
Choosing Hardware:
Dedicated recording hardware is another essential tool for a musician’s tool box. You can use a PC or MAC’s built in sound
card to get “CD Quality” recordings, but this method introduces many limitations.
When recording, latency becomes a huge issue.
Latency is the time it takes for a computer to process incoming sound and
record it to a hard disk. This becomes
an problem when a musician wants to record vocals, or an instrument while playing
back other tracks. If the latency is
greater than zero then there will be a delay between the recorded track and the
track that is being monitored. Most
computers have sound cards with built in latency of more than 300 ms.
This means that when recording a vocal track it will lag behind the instrumentals
by more than a third of a second. Some
advanced recording software allow correction schemes to bring the latency back to
zero. When purchasing recording hardware
take note of the claimed latency specification.
Enhanced hardware and drivers can allow for latency of less than 10 ms.
Another differentiator when choosing recording hardware is sample rate and bit depth. See the Hardware Basics section
for an in depth explanation of these variables.
Higher numbers are usually better so 24 bit 96 kHz is good but 24 bit 192
kHz is better. When comparing choices,
also note the signal to noise rating, each A/D and D/A converter has some level
of noise. This specification is given
in dB’s. Higher numbers are better,
100 dB SNR (signal to noise ratio) is good, while 110 dB is better.
Recording stations exist that have the ability to perform multi-track recording
in one self contained device. This
is a nice solution for those who want to keep things simple while at the same time
having a portable, complete solution.
These units have on board storage with the capability of exporting a project or
mastered track using a CD, zip drive, removable hard drive, or other removable storage
medium. These solutions are often more
expensive than using an existing computer with added recorder.
The preferred recording solution typically involves using a computer with an after
market piece of hardware. This hardware
is grouped into three categories which are denoted by interface type.
1.
Good quality PCI hardware can be purchased with tons of inputs and
outputs at a reasonable price. On a
recommendation, I purchased the M-Audio Delta 1010lt.
For $199 you get a PC card with 10 ins and 10 outs.
The card includes two mic preamps, S/PDIF I/O support, zero latency hardware
monitoring, 24-bit 96 kHz resolution, and MIDI I/O.
If you need more than 10 inputs, you can add more 1010lt cards.
Other PCI based solution also exist, the downside to this interface type
is the lack of portability. Once you
choose a tower to install the card, you will most likely leave it there.
These types of interfaces do not work on laptops or other PCI unfriendly
computers.
2.
The most common computer interface is the USB type.
Easily portable, external box solutions exist that use this interface and
most are powered by the USB port so no additional supply is needed.
The majority of these boxes have one mic input with a preamp, built in Phantom
Power for condenser mics, an instrument input, and a headphone jack.
These boxes almost always share the input between the mic and instrument
connection. Even if promotional material
states that it has both a mic and instrument connection, be careful, you can typically
only use one or the other at a time.
If you have a guitar and want to sing simultaneously, purchase a unit that has two
mic inputs and two instrument inputs.
A major downside to this interface is the small bandwidth offered by the USB protocol. I purchased an M-Audio Fast Track Pro
and found that maxing the resolution meant that the monitor would shut down, I could
sing but not hear the instrumental track.
Lowering the bit rate allowed me to use the product, but for $199 my expectations
would be to use the highest bit rate and highest possible sample rate together. Most of these units offer a MIDI port
which allows for a keyboard or
MIDI
based controller. A
MIDI
based controller is a huge time saver when mastering your final mix.
3.
My preferred interface is FireWire.
FireWire devices have a much larger full duplex bandwidth than USB, are very
portable, and offer the ability to stack units on one control line increasing the
overall channel count. FireWire bandwidth
allows for maximum full duplex audio resolution.
The price per unit is comparable to USB solutions with similar connection
architecture. An example device is
the $399 Alesis io which offers 26 channels (8 analog) of 24-bit 192 kHz resolution,
with MIDI I/O, and S/PDIF connectivity.
Starter, single input FireWire devices also exist and can be purchased for less
than $150.
Recording Software
Most hardware recording devices come with either a trial version of software, or
a fully functioning baby version. Computer
based software typically has a steep learning curve.
Be prepared to spend extra money on lessons, or purchase auxiliary instruction
material. From my experience, the embedded
help file is not enough to become proficient at a complex piece of recording software. Some software is semi intuitive; I was
able to perform complex tasks using GarageBand on the Mac, these same tasks took
days of help file searching in Sonar.
It’s easy to be frustrated using a new piece of software; hang in there, the payoff
is almost always worth the initial energy.
Good Luck.,
Justice Richards