The versatile and compact RME Fireface UCX interface includes onboard DSP effects.
Are you ready to continue our quest
for the best home studio gear? In last
month’s column [“Choosing an Audio
Interface,” May 2012], we looked at one
of the primary pieces of gear in most
modern studios—the audio interface. By
talking about inputs and outputs, monitor
outputs, and headphone outputs, we’d
gotten as far as considering an interface’s
basic connectivity. This time around, let’s
delve even deeper into I/O territory and
also touch on some other features and
extras that will help you narrow down
your interface choices.
MIDI I/O. MIDI signals are used to
control various pieces of equipment, as
well as store performance data from keyboards,
drum controllers, guitar synths,
and more. While many synths and drum
machines are virtual instruments or software,
and USB connections are available
on a lot of new gear, you will still likely
run into the need to connect a device by
MIDI sooner or later. You might have an
older keyboard with MIDI connections.
Or it may be a digital processor that needs
to connect to your computer so you can
edit patches, update the software, or back
up presets. In these scenarios and others,
it’s necessary to have a MIDI input
and output available. While you can buy
separate MIDI interfaces, having the connections
built into your audio interface
means one less piece of gear to purchase
and hook up.
Word Clock. Digital signals can be
very picky about who’s in charge. When
routing signals in S/PDIF, AES/EBU, or
ADAT Optical format, one device has to
be the master and the other has to be the
slave. The master establishes the sample
rate and locks everything together, while
the synchronized slave follows merrily
along. This is easy in a basic system where
you’re only sending around one digital
signal. In fact, it may all be handled in the
background by your software, without you
having to worry about it.
But in a more complex system—be it
mic preamps with digital outs, effects with
digital ins and outs, or a digital mixer—
managing digital synchronization can
take a bit more planning and effort. Word
clock I/O (often carried on BNC/barrel
connectors) makes this easier since the
digital clock part of the equation can be
separated out from the digital audio signal
and managed independently.
Perhaps we’ll dig deeper into this in a
future column, but that’s as far as we need
to go into word clock I/O for now. Having
word clock I/O may or may not be a dealbreaker
for you, but it’s definitely a handy
bonus to have on your interface.
Mic Preamps. Microphones put out
very low-level signals that must be preamplified
before other electrical devices
can deal with them. Having built-in mic
preamps means that you don’t need to
purchase additional gear for routing microphones
into your interface. And the number
of mic preamps in your interface will
determine how many mics you can plug in
at once. Though it may seem like a good
idea to go for the most mic preamps possible,
be realistic about what you really need.
Unless you are recording multiple musicians
at once, one or two may be plenty. But
you’ll need at least eight mic preamps, if
not more, to record a full band. If an interface
doesn’t have enough built-in preamps
for your projects, you can always add more
and route them into the analog inputs of
your interface (assuming the interface has
enough free analog inputs). Other features
to look for include phantom power, which
will allow you to use condenser mics with
the interface. Also, a low-cut/high-pass filter
is useful for cleaning up low-frequency
rumble when recording with a mic.
Control Room Features. Some
interfaces with monitor outputs provide
additional “control room” features, such
as the ability to switch between two sets
of speakers. Interfaces with a dim switch
allow you to reduce the speaker level so
you can converse with your collaborators
without stopping playback, while a mute
switch will temporarily silence the speaker
output completely. Other interfaces
include a mono switch for summing the
stereo output to a single channel, which
is handy for checking for problems with
phase cancellation in the stereo outputs.
Direct Monitoring/Latency
Management. Sending an audio signal
into an audio interface, converting it to
digital, sending it down the line to your
DAW software, turning around and sending
it back out, converting it back to analog,
and then routing it to your speakers
or headphones takes some time. And the
time it takes will cause a delay that can
often be audible. This delay is called latency
and it can be especially problematic
when overdubbing tracks. Many interfaces
have special features for reducing or eliminating
latency, and I consider it essential
to have this technology onboard.
Onboard DSP. Some interfaces feature
built-in chips that can be used for a variety
of tasks. While some use onboard DSP for
handling latency, others use these built-in
chips for generating reverb, delay, or other
effects that can be used when tracking.
Having effects available that don’t add
latency or load down your computer can
be a godsend in certain situations—many
a take has been saved by providing “comfort
reverb” for a singer who isn’t used to
singing in headphones. Though onboard
DSP isn’t a must-have, it is a useful tool.
Metering. Level meters on your interface’s
front panel can be a real help in
recording healthy levels without worry of
clipping or distorting a track.
With that, we’ve completed our discussion
of both the computer and the interface—
the core of our system. Next time,
we’ll start looking at capturing and monitoring
our signals!
Mitch Gallagher is
the former editor in chief of
EQ magazine. He’s written
more than 1000 articles
and six books on recording
and music technology, and
has released an instructional
DVD on mastering. His upcoming book is
entitled
Guitar Tone: Pursuing the Ultimate
Electric Guitar Sound. To learn more, visit
mitchgallagher.com.