Hey
there podcast friends, Pod Sound School is in session. Learning is the only thing the
mind never exhausts, never fears and never regrets. Let's go.
Hello again podcast-prenuers. How are you feeling? I'm Studio Steve and this
is Episode Five. Today we're going to discuss an exciting topic, Interfaces. So far we've
covered acoustics and the treating of our room and reduction and control of noise. Then
last time we talked about microphones, dynamic and condenser. Now that your room is treated
and you've decided on a microphone we need to record our voices into a computer and put
together our podcast.
The first stop after the microphone is our interface. This is the piece of equipment
that we plug our microphone into that then connects to our computer or laptop, most commonly
nowadays through a USB or Thunderbolt port. What is an interface? What does it do? How
does it work? What kind of brand do I need? Like all the episodes on the first season
we'll be staying on the surface of how things work. Next season we're going to dive deeper
into the technicalities.
Once of the best ways to learn is to just start doing it, start playing with your gear,
pushing buttons, making practice recordings, etc., but having a basic understanding will
help you make an informed decision on what gear to purchase and save you time in the
fumbling around stage. Let's quickly talk about audio interfaces. The audio interface
is really the boss of your computer recording system. It performs many functions and has
many key elements.
For today's discussion we'll quickly talk about the five basic aspects of an interface,
preamps, converters, sample rate and bit depth, MIDI and in and outs. If that sounds like
a lot and maybe even a different language, not to worry little pod-a-neers.
It's actually pretty simple once you break it down.
Number one, preamps. If you remember from the microphone episode, we talked about how
the microphone converts the vibrations in the air into an electrical signal. Well, once
it's been converted into an electrical signal that signal is then sent through a microphone
cable and plugged into our interface. From here the first place the signal comes in contact
with is one of the interfaces built in preamplifiers. What a preamp does is to boost the low mic
level signal into a more powerful line level signal. This line level is necessary for recording.
The quality of the microphone and the quality of the preamps are really the two biggest
factors in how the recording turns out. A good quality preamp is necessary to really
hear the full potential of your microphone. Many of the consumer brand interfaces are
built with preamps that are not very high quality. For this reason it's popular to purchase
a preamp separately from your interface and simply use the line inputs on the interface
instead of the mic inputs. If you'd like to hear more about preamp recommendations, contrast
and comparisons, check out our blog at PodSoundSchool.com/blog.
Only a fraction of the couple hundred dollars you'll spend on an entry level interface is
going toward that preamp. On the other hand, if you spend a couple hundred dollars on just
an entry level preamp, who's only circuitry is dedicated to boosting mic level, you'll
have much better results. A really expensive microphone will sound like garbage ran through
a garbage preamp and a cheap microphone can sound really great being ran through an expensive
preamp.
Although that expression you get what you pay for definitely applies to audio production,
that doesn't mean that you have to spend thousands of dollars to achieve great sounding vocals
on your podcast. If you're on a super tight budget, you can check out the Penny Pinchers
Alternatives episode where we discuss the cheapest and quickest ways to get going.
The next most important factor is number two, the converter.
You'll make this rather snappy, won't you? I have some very heavy thinking to do before
10:00.
After the preamp has added power to our microphone, the interface will send the signal to an AD
converter, which stands for analog to digital converter. This is where the interface converts
the analog signal into digital data.
A gigantic series of ones and zeros.
The job of the AD converter is to make this transformation as accurately as possible.
Once the signal has become digitized, the interface then sends the signal through the
USB or Thunderbolt cable into the computer to be recorded and manipulated by the recording
and editing software, while performing this magic task at almost the same moment that
the interface also collects the sound coming out of the computer through the same USB or
Thunderbolt cable and brings it back through another converter called the DA converter.
Yep, digital to analog. This converter takes the giant stream of numbers and transforms
them back into an analog signal that can be sent to speakers and headphones.
Wow Rhonda, who designs this stuff?
I know, right?
Number three, sample rate and bit depth. The terms sample rate and bit depth are selling
points of interfaces. These terms are functions of the converter. Sample rate is basically
how many pictures the AD converter takes of the sound per second. The measurement for
this is in kilohertz. You'll see this written as kHz. Kilo stands for 1,000, so for every
one kilohertz, the AD converter will take 1,000 pictures of the analog audio. Bit depth
is basically the quality of each of these pictures. The higher the quality of picture,
the tastier the sound.
The more pictures you take per second and the higher quality of those pictures will
give you a better and more real to life sound, but it will also give you larger file sizes.
The only thing you really need to understand about sample rate and bit depth is that as
the numbers get bigger, so does the audio quality. With that being said, you don't need
the highest available numbers. Currently the highest end interfaces offer 32 bits and 192
kilohertz. This creates much larger file sizes and really isn't necessary to achieve sweet
sounds.
A majority of podcast audio and music producers do just fine with 24 bit and 96 kilohertz
or 96K, and not that anybody exports their music to CDs any more, but to put those numbers
into perspective, the sample rate of a CD is 44.1K and the bit depth is 16 bit. We'll
get into this more later when we talk about exporting your MP3 for iTunes or for your
web host.
Number four, MIDI. MIDI stands for musical instrument digital interface. This allows
you to connect a MIDI keyboard or another MIDI controller to your computer. There are
countless digital instruments or virtual instruments that can be controlled from this MIDI input.
Lastly, number five, ins and outs. This is what it sounds like, inputs and outputs. How
many inputs and outputs an interface has varies a lot. How many you need depends on your intentions.
How many microphones will you be using? How many hosts or cohosts do you have? Will you
have guests? How many headphones do you need to support? Are you also going to use the
interface for music creation? All of these considerations will let you know how many
inputs and outputs you need. You really want each voice or each instrument to have it's
own input and channel for optimum control and quality.
There are work arounds using mixers where you can send multiple microphones through
one or two inputs, but this won't allow you to adjust each voice separately later in mixing,
so if you're planning a round table podcast with five friends and occasional guests you
might want to get an interface with six to eight inputs. If it's just going to be you,
or you and a cohost, then a two input interface will probably be just fine. However, since
you're already making an investment into an interface, it's never a bad idea to leave
yourself a little room to grow and that's our quick rundown on interfaces.
What did we learn? One, we need a tasty preamp. Two, AD and DA converters change the analog
signal into a digital signal. Three, sample rate and bit depth, referred to audio quality
and file size. The bigger the number, the higher quality and file size. Four, MIDI lets
us plug a keyboard into our computer and play and record virtual instruments. Five, ins
and outs are how many inputs and outputs an interface has.
There you go. Always a pleasure getting with you and chatting about audio toys. If you
have any questions you can shoot me an email directly at StudioSteve@PodSoundSchool.com
and of course you can come along and find us on our social medias @podsoundschool and
if you really want to dive in head first and make a dent in the world come get involved
with the overachievers club over on our Patreon page, Patreon.com/podsoundschool. Great job
today everyone and I hope you're not thinking about giving up. I'm really excited to help
you sound your best. Happy casting.
Did you learn quite a bit? I know I did darlings. Remember, success is walking from failure
to failure with no loss of enthusiasm. Goodbye for now.