We're building our own cheap DIY 2-channel audio
analyzer so we can run Smaart, SATlive, SystTune, whatever you want to run and
we already talked about the microphone so if you haven't decided on your
microphone yet go back and watch those videos. I guess the question that I want
to ask you guys is does it really matter if I use this audio interface or this
audio interface? What features are best? Do we really care?
You should use whatever you have already so you can just get started with
practicing right now really the only requirement is that it have two balanced
inputs so why do you need two balanced inputs well to do a transfer function at
a two channel measurement what we're gonna do is compare the input to the
output so we want to compare what's coming out of our mix console or out of
our audio interface in this case with whatever is the device under test so we
were just measuring a speaker in the last video so we want to compare what
we're sitting to the speaker with with actually being received at the
microphone with what's actually happening in the room okay so we're
gonna have a channel here for our reference input that's what we're gonna
say here's the piano or sending the piano out into the room and then we've
got our microphone in the room and that microphone is gonna say okay I'm getting
a piano or I'm getting an airplane or I'm getting something in between it's
gonna show us the contrast between the reference and the measurement so here's
what I recommend everyone do who is just getting started
get one of these get a white able so that you know for sure that you are
always sending a copy of the exact same thing and what you're gonna do is you're
gonna take your two channel audio interface and you're going to connect
the output
like that and you're going to take one of those splits and immediately connect
it to the input that is your reference channel that's why we have over here on
the input settings a measurement channel and a reference channel this loop that I
just created okay output to input that's our reference it can be as simple as
that so it can be really fast to get set up if you just want to measure something
quickly like let me just measure the speaker or let me just measure this
graphic EQ or let me just measure this console set that loop up that's your
reference okay so if you have something like this
rolling duo capture this is what the split is doing okay here's a warning if
you have one of these kinds of audio interfaces which I have right over here
doing the recording right now it has this knob here right this mix knob from
input to peanut butter what you want to do is make sure that you do not have it
set on input because that will create a feedback loop so when you're doing your
measurements turn off direct monitor and set your mix all the way to peanut
butter okay all right so we've got our cheap option
right which is $75 $150 otter audio interface that you can get and we've got
a free option which is whatever microphone and audio interface you
already have around the house right now we'll a one thousand dollar audio
interface give you better signal-to-noise ratio yes and doesn't
have more features that you can play with yes but again that's not super
important right now what's important right now is that you have a tool that
you can get started with practicing taking these measurements and
interpreting the data okay one platform consideration if you want to do
measurements on the iPad you can do that you generally need a battery-powered
audio interface which is why a lot of my students like the Roland duo capture one
more possibility if you often use an X 32 or M 32 you already have an audio
interface right you can just take the output here from the board connect that
to your computer and you're all set now I do recommend that you eventually
get a separate audio interface so that you have a separate measurement unit
that's not connected to the board that way you have something that you know
works and you know how it gets connected and it's faster and it doesn't matter
what console is there when you show up but if you own an x 30 your own x 32 or
you're always doing shows with that why not you can have a template set up that
has all the routing done for you already and you can get up and running really
quickly so if that's your case I recommend that you watch this video from
Donovan Klein and I'll put a link to it below this video all right so that's the
shopping for the audio interface don't spend too much more time on this in the
next video we're going to talk about how to choose which software you should run
sound design