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Tools FAQ
Quick answers to your questions from the Transom Tools Column.
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Answers
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Getting Sound Onto a Computer
- Analog Answer:
Plug the line-out (analog) of your recorder into the analog line-in of
your computer (older Macs have built-in, some PCs and new Macs need an external
soundcard). Launch your computer's sound-recording software, set a level,
hit record on your sound software, then play on your recorder. Make sure
you know what audio level your soundcard input is set to receive (mic level
or line level) and adjust your output levels accordingly. It's best to feed
as loud of a level as possible before distorting, rather than fixing it
later. To that end you may want to use a mixer to regulate the levels,
or in a pinch, use the headphone-out of your playback device, adjusting
the volume to show strong levels on the input meters of your computer's
recording program. That's one way, but there's a better way...
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USB Digital Answer:
If your computer has a USB port, use it to capture audio. You may have
no choice if you have one of the newer Macs, which have USB ports but no
Audio-in. This can save one or two additional analog/digital conversions
of the sound, and so, will sound better, especially if you can keep your
signal digital. You'll need an external USB audio device (US$35 to US$600).
This allows a real-time transfer, not a data copy, but it will get audio
in and out of your computer without installing a card, and usually with
better quality than an off-the-shelf computer sound input.
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Firewire Digital Answer:
Fireware, aka IEEE1394, is the most common method of capturing video
into a computer. Firewire transfer rates (400Mbits/sec) are many times
faster than USB. Most consumer portable movie cameras now have a built-in
firewire port. We in audio, however, are somewhat behind our video brethren.
Firewire interfaces allow simultaneous multi-channel audio recording and
playback. So far, all these devices are at least one full 19" rackspace
in size, and often require external AC power, which makes them less convenient
for the mobile recordist. But these interfaces can transfer more channels
of audio simultaneously than USB allows, offer more input and output choices, and usually include at least two built-in mic preamps, making them a versatile tool for a small studio as well as for remote recording.
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PCI Card Solutions:
An installed PCI card can give greater bandwidth than a USB device, allowing
more simultaneous channels of input and output, and there are many to choose
from, from basic $200 models to high-resolution multichannel systems for
tens of thousands of dollars. The popular Digidesign Audiomedia card has
been discontinued, replaced by the M-Box USB interface, but there are many
others with similar capabilities from M-Audio,
Echo, Aardvark,
Digigram, Digital Audio Labs, Hammerfall
and many others. There are many software/interface systems, fom the project-studio
oriented digi001, or MOTU
2408 to Steinberg's Wavelab
and Nuendo, to pro-studio,
high-overhead systems that allow simulation of large multitrack tape machines
and mixers. But one should try to keep an eye on how much horsepower is
actually required to create your radio program, and perhaps spend the extra
bucks on a better microphone.
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Can't I Just Copy the Data Files From My Minidisc?
No. At this time there are no systems that allow direct transfer of the
digital files from a minidisc into an editing program. Even the HHB Portadisc,
which will transfer audio to a computer via USB, is transfering digital
audio, in real time. Be aware that the small consumer portable minidisc
recorders that advertise a USB connection are designed to load digital audio
onto the minidisc from the computer via USB, and not the other
way around. And even if we could copy the files, it's unclear whether any
digital editor would work directly with them, as sounds are not recorded
as standard aiff, wav or SD2 files.
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Why Can't I Output "Digital" Audio From My Consumer Minidisc?
Many of the small consumer minidisc recorders have optical digital audio connections but they are, like the USB connection, designed to load sound onto the minidisc, not the other way around. These consumer devices are designed for casual music listening and a few features are missing. However, these inexpensive recorders are still a good alternative to an analog cassette or even DAT, and one can get very good audio quality by taking the analog outputs of these recorders and loading them into the computer by one of the methods described above. At this time the HHB Portadisc is the only machine we know that allows direct output of minidisc audio over USB.
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What Cable(s) Do I Need?
This depends on your specific recorder and computer interface. Many computer soundcards and Mac built-in sound use the same type of connector as the consumer minidisc recorders: a 1/8" stereo "mini" connector. In this circumstance you need a cable with stereo mini connectors on each end (there are three conductors: the tip, ring and sleeve.) If your minidisc player has a "line-out" use that, if not, use the "headphone out". The line-out will be at a fixed level, while the headphone out will have a variable output level, controllable from the front panel. This can sometimes be an advantage, allowing you to optimize the input to your computer. If your computer's sound input will only accept microphone levels, you will get excessive noise and distortion when you connect a line-level input. There are not a lot of devices built to knock-down signals to mic level, but an attenuating cable can help, or a headphone-extension cable with a volume control, or most of the the Mackie VLZ-series mixers can output microphone level from their main XLR outputs with the push of a button. But rather than dropping your levels down, only to amp them back up again inside an electromagnetically chaotic computer, or using a noisy headphone output, try using one of the line-level interfaces described above instead.
If your soundcard has different connectors, or if you are using a mixer in-between the minidisc and the computer to regulate your levels, you will need a cable with a stereo mini on one end, that splits to two of whatever connector matches your soundcard or mixer, probably RCA plugs or 1/4" plugs. Make sure you are not getting a mono splitter or "Y-cable" that sends the same signal to both outputs, you want a cable that sends left and right signals to the seperate RCA or 1/4" outputs. These cables are commonly used to connect a "walkman" style CD player to a home stereo.
If you are lucky enough to have a pro deck with a digital output, invest in an interface that accepts digital signals and use that.
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Software Questions
- What Recording/Editing Software Should I Use?
Your personal computer can also become a multitrack audio recorder/editor/effects-processor/mixer.
All you need is the right application. The programs most commonly used by
independent radio producers are Digidesign's ProTools (usually the
Free, or LE versions) and Syntrillium's CoolEdit.
Which program to use depends on your needs (are you just editing dialog
to be mixed elsewhere, or producing a complex, layered piece?) and the type
of computer you use.
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Computer Troubleshooting
- Is My Computer Ready To Edit?
There are a myriad of reasons why things might not be working in concert with one another. Before you buy something, check the company's website and make sure that it is appropriate for what you want to do. Editing programs will give indications of minimum computer requirements, interfaces will usually indicate which programs they will connect with, etc. There is always a risk of a conflict with some hardware or software in your particular set-up, but here are some general rules that will reduce these problems:
1) Buy as much RAM as you can afford, and your computer can hold -- RAM is cheap and makes the most cost-effective improvement in sound-processing. (It also can determine how many tracks and effects your software can handle.) It is NOT overkill to load up your machine with 500 megs or more.
2) Set your sound software's memory allocation (the amount of RAM the program uses) to high: 100M or more. Try to run as lean a system as possible, only running needed programs and system exensions, leaving more processing power open for your audio work.
3) The faster the clock speed (in MHz: Mega Hertz) of your computer's CPU (Central Processing Unit), the faster it will process sound.
4) The larger your computer's harddrive (in M: Megabytes), the more sound it can store.
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What Sampling Rates Should I Use?
Use these minimum sound sampling rates for radio production: 44.1KHz, 16bit, uncompressed (the rate used for Audio CDs). It's true that FM broadcast does not take advantage of the full 20 khz bandwidth of this resolution, but recording and editing at lower bit-depths or sample rates will often result in murky, noisy sound. Better to get some additonal hard-drive space.
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Microphone Questions
- Which Microphone?
There is no one answer for everyone. For more details, check out the
transom tools What Microphone Do I Get column, but the main decisions
are these: omni or directional, dynamic or condenser,
handheld or lavalier, mono or stereo? There
are a few additional challenges when using a small consumer minidisc recorder,
as the mic input is a high-impedence 1/8" mini connector, while most
pro microphones are low-impedence with XLR connectors. Get a high-quality
cable, wired for this purpose, with an 1/8" mono connector on
the minidisc end if you are using a single mono microphone. It may be worthwhile
to get a cable that adapts from XLR to mini and also adjusts the impedence
and shunts the plug-in power. The Shure A96F
does all of these things.
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Which Pick-up Pattern?
Omnidirectional mics pick-up sound from all directions equally,
while directional mics pick-up best in a limited zone, usually in front
of where you aim the mic. An omni mic is more forgiving of imperfect placement,
and will sound more natural if the source is not directly in front of the
mic. Omnis are also less succeptible to handling noise, wind and p-pops.
Directional mics give a tighter, more focused sound, and will
record less of the surrounding ambience, which can be good or bad depending
on your intent. There are degrees of directionality, from the cardioid,
a fairly wide pattern that is very practical for close-up interviews, to
the shotgun, which has a very narrow angle of sensitivity, best suited
for more distant applications. In-between are hypercardioids and
short-shotguns. As directionality increases, handling, wind and breath
noise become more of a problem, and off-axis sounds seem increasingly unnatural.
For field recording and ENG (electronic news gathering) the most popular
omni mics are the Electrovoice
RE-50 and the Beyer
M-58. The most-used cardioid mic is the Shure
SM-58. Shotgun mics by Audio
Technica and Sennheiser are
frequent choices.
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Dynamic or Condenser?
Dynamic mics are more durable, can handle higher sound pressure levels,
and require no additional power. Condenser mics have a louder output and
can pick-up more subtle details, but require phantom power. That power can
be provided by some recorders, a mixer, an external device, or sometimes
an internal battery. Many of the small consumer minidiscs have something
called "plug-in power" which is similar to phantom power, but
cannot power professional mics. It provides power for electret mics designed
to be used with these recorders.
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Handheld or Lavalier?
In most cases you will get better sound quality with a handheld microphone.
Lavaliers are not placed in an ideal position and often pick up clothes-rustle.
But there are circumstances, such as an intimate conversation where an obvious
mic would interfere with the feel of the interview, or a subject moving
in such a way that keeping him or her "on-mic" would be impossible,
where a lav can save the day. But with the up-close feel of current radio
styles, lavs can often sound distant or muddy.
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Mono or Stereo?
Stereo sound can add a lot to the vividness of your location recordings,
but can be quite distracting during interviews. So you may want a stereo
mic for ambience and demos and a mono mic for interviews. See the transom
stereotypes column for details on techniques and two-mic arrays.
The inexpensive stereo mics that are sold to go with consumer minidisc recorders
can get decent sound, and may be more than sufficient to get some backgrounds
for your piece, but they are not particularly durable, often made of plastic,
and have limited bandwidth, reducing high-frequency detail. Better choices
are the relatively inexpensive AudioTechnica
822, or the Sure VP-88.
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Why Can't I Get Enough Volume From My Mic?
Some users have reported problems getting enough level into their minidisc
recorders. Make sure you are manually setting the record level, the automatic
gain control rarely sounds good. Many of the little Sony minidiscs have
the irritating feature of only allowing level adjustments while the deck
is in pause, so you have to pick a level and stick with it. If you have
the record input level turned up all the way (this adjustment may be a few
levels down in menus, it is NOT the volume + and - on the top of the deck,
that's the headphone volume) and you still aren't getting enough level,
you have a few options. Make sure you have a good quality cable, not a pieced-together
series of adapters and mis-matched connectors. If you're using a dynamic
mic, you may want to try a condenser instead, they almost always have a
louder output. Condenser mics require phantom power, so be sure to pick
one that can use an internal battery, unless you have an external source.
A consumer minidisc recorder's "plug-in power" will not power
a pro mic. Another volume-increasing tactic is to use an impedence transformer.
The 1/8" connectors on small minidisc machines are high impedence,
while pro mics with XLR connectors are almost always low impedence. You
actually don't want the impedences to match exactly, but raising the impedence
a bit can give you a few more dB of volume. A cable like the A96F
from Shure will do both things: convert your XLR to a mini and raise the
impedence enough to give a bit more volume.
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