This is Hacker Public Radio episode 3,673, her Wednesday the 31st of August 2022.
Today's show is entitled, Recording for Hacker Public Radio.
It is part of the series podcasting how to.
It is hosted by D&T and is about 18 minutes long.
It carries a clean flag.
The summary is, my experience is Recording Episodes of HPR.
Welcome to another exciting episode of Hacker Public Radio, this is your host D&T.
This one is prompted by an email conversation with Carl.
He wrote to a few of us sending some samples of some recordings that he had made of himself
and he wanted to get some feedback on it.
Carl, you may remember he was the one that put together that collaborative episode with
some shell snippets and I sent a clip to that show.
Carl's email he mentioned that he thought my clip sounded pretty good and so he thought
I might have something to say about Recording Audio.
So that was pretty funny because of how I actually recorded that clip.
So it was different than any previous episode of Hacker Public Radio that I recorded
because I was at work and there were only two days in which to submit the clip because
Carl had helped fully set a deadline for this.
So I had only two days I was at work and I didn't have anything to record it with.
So I went to the Play Store looking for an app I could install and for simplicity I just
looked for something I recognized.
I was hoping there would be an app from like Zoom or Road or something like that.
One of the audio equipment manufacturers and as it turned out I found one that was called
Dolby on.
So that was how I recorded that episode and I agree with Carl, it sounded quite good.
It sounded a lot better than any of the prior episodes that I had edited myself.
So clearly the people at Dolby are cooking some fancy filters there without telling us
about it and it's doing a pretty good job and it seems.
So before that I had recorded HPR episodes in a few different ways.
The first one I think I recorded it in an iPhone 7 with the earbuds that come with the
iPhone 7.
Then later I think there was at least one that I recorded using a Zoom H1 which is a small
handheld recorder one of those that have like an X, Y pair of microphones.
It's like a stereo.
It's really nice for recording ambient sound.
For recording voice it picks up a lot of background noise anyway.
Then I used the application that was shared by Norris here on Hacker Public Radio.
It's called Solo Cast.
It's a Python application on the command line.
You prepare this script and then the application will show you the script one paragraph
at a time.
You record the paragraph and then it'll ask you if you like it or if you want to re-record it.
Once you have recorded all of your segments it'll splice it all together for you and do
some normalization and a couple other things I guess.
So I used that with this headset that I used that work for calls.
That's called it's the Sennheiser MB Pro 2.
It's decent.
It's pre-convenient but it doesn't sound very good I guess, not too good.
And then finally this Dolby on app and then here I am recording the second episode using
this app.
It is not free of course, so leave your comments on that if you want or record your own
show about this use of non-free software and what it means.
I want to hear your opinion on that.
So then going back in time a little.
So I went to college for film and during that there was I had one class that was about
sound and I also paid a lot of attention to sound recording and sound editing as well for
my own interest but during this class we learned a couple of things about editing
sound.
First mainly we learned about the compressor and EQ.
So talk about the compressor first.
The compressor is you usually visualize it with this graph so you're usually going to have
a setting that's called the threshold.
It's going to be in decibels like for example I set the threshold to 16 decibels.
So what that means is up to 16 decibels the filter is not going to do anything to it.
In any sound that is above 16 decibels it's going to attenuate.
It's going to attenuate following another setting that's called the ratio that's going
to be something like 4, 4, 1 for example.
So the ratio is how much you're going to attenuate that sound that's above the threshold.
So if the ratio is very very high that means you're practically going to flatten anything
that goes above 16 and you're going to take it right down to 16.
What you're doing with that is if you're someone who's volume, who's speaking volume
varies a lot it's going to kind of even that out a little.
And imagine for example if you're recording someone playing the piano and they tend to
hit the keys really hard sometimes which in person it can sound very good but to a
microphone it can be very challenging.
So the compressor is one of the things that can help with that.
The compressor usually also has a setting that's called gain.
That's basically just gain and it's just there because typically you're going to attenuate
the top of the peaks there and you're typically going to want to lift up everything
after that to bring it up closer to the peaks you want right.
So you shouldn't overdo it with the compressor because I think it can make things a little
monotonous if the volume is kind of always the same.
So you know it can make it sound less natural or something like that.
So you don't want to overdo it but certainly I think with voice over with bond casts
with you can get away with with quite a bit of compressor I think if you disagree just
let me know in the comments.
So at this class in college honestly the professor never really talked about normalization
if I can remember it right.
Really I think what we would do is we would just try to get just with the compressor alone
and we would try to get as close to the peaks that we are targeting as we can and then
we would just do that the normalized would be like at the very end.
So the getting to the peaks that you're targeting what that means is like I think nowadays
with online stuff you can easily go to minus 3, even minus 1 and that's just fine.
You may hear stuff about peaks having to be at minus 12 or minus 16.
I think that's really kind of a technical standard to do with broadcast video and broadcast
radio.
I don't think it's really relevant anymore so you can go a lot higher than that and most
people I think do.
So you would try to get as close to that as you can with the compressor and then use the
normalized to get right there then EQ.
So the professor taught us this interesting technique I think he called it the sweep.
So the EQ or it is like let's imagine a graphical equalizer and you have the spectrum
right there in front of you on the left are the highest the lowest frequencies that is
the low pitch stuff and on the right are the high frequencies the high pitch stuff.
So then typically you would have a line going from left to right and with the graphical
EQ you're going to mark some points there at different frequencies and then you're
going to attenuate or boost the signal at those frequencies.
So what that's going to do is for example if you put some points here on the left and
then attenuate them a lot your you know your voice is going to sound less low pitch.
There is also a setting then I don't remember what it's called but it kind of makes
it makes the curve more closed or more open so that if you boost the signal at one point
and you make the curve more open you're going to be boosting a lot of the neighboring frequencies
right there.
So the sweep that this professor taught us what it was is you would start on the left of
the spectrum you would mark a point make the curve pretty closed and then you would boost
it quite a lot and then loop through a piece of your of your recording maybe pick some
part that that you think is kind of represented for whatever reason just played in a
loop and then move your the frequency of your point from the left all the way to the highest
frequencies and listen as you do it.
So as you listen the sound of course is going to change because you're going to be boosting
all these different frequencies and you're making you may notice some things keep your
ear out for parts that sound really kind of nasal just kind of annoying or something just
but whenever it sounds really terrible when the signal is boosted stop and take a note
of what frequency that was okay and then keep going then when you get to the end of the
spectrum you will have written down maybe like three frequencies or something like that
so then drop points at those three frequencies and then attenuate them a little and
this time use a much more open curve and then see how that goes and then now it's going
to be trial and error just try a few different things here and there and see how it sounds
I think you would expect to for it to sound more pleasant to the ear if you just do that.
Now there's also boosting the signal at different points I don't know much about that to
be honest I know there are areas of the spectrum that you can boost that can help your
voice somehow but I don't really know how exactly so I don't think I'm going to be very helpful
there.
What you can do also is just look for some presets in your editing application that are
named for things like voice over or vocal whatever it is and see what they do and then
just try those things out with your own EQ for your voice right so basically just do this
once for your own voice for your environment that you're going to be recording in the
typical environment you're going to want to keep consistent and then just save it as a
preset for your voice so then you can just apply it to your recordings going forward.
Now a kind of a thing I would say too is EQ is pretty subjective as is I think sound
editing largely I think so I think the only thing you can do is kind of lean into it
and just just see what things sound like to you and see if it feels good or not and just
go by that you know it's all you can do so then it's easy also to get for your ear to kind
of get used to sounds so a lot of times it's worth doing this and then stopping putting it
away and then come back the next day listen to it again see if you still think it sounds good
a lot of times you'll you won't any more for whatever reason so it's worth doing that now
I talked about you're setting the EQ for you're saving a preset for your environment that
you're going to want to keep consistent now this is much more important than the EQ and the
compressor to be honest if you do no EQ or compressor but your environment is great
your recording is going to be great if you do if you spend 24 hours on EQ and all the other
stuff noise removal whatever but the environment in which you recorded it was crap it's not
going to sound any good no matter what you do so you want to look for a place that it's as little
noise as possible and as little reverberation as possible reverberation comes from mainly from
flat surfaces so if your room has a lot of flat surfaces and like the walls for example and no
furniture sound is going to bounce back and forth a lot there's going to be a lot of reverberation
this is the thing that's going to sound the worst in the recording so it should be the number one
thing you consider or maybe not the number one thing but one of the top things you consider
so you know a carpeted room or room with more furniture stuff on the walls will eliminate
the reverberation really quickly actually of course there's also equipment you can buy for that
if you want so one thing that a lot of people will do is they'll just go in a closet and record
in a closet guess pretty warm but it works very well there's lots of clothes in there so
it's going to sound pretty much like you're in a sound studio and another thing is the car like
the clip that I recorded for Carl's show I recorded in the car cars car manufacturers have
made cars a pretty hospitable environment for sound so if you have a car it's worth trying that out too
and then finally the time of day pretty obvious you know for example don't record it when
your sprinklers come on and then you can hear the the water flowing through under the house
then breathing and warming up really important things too this is something I've noticed in myself
for sure whenever I recorded an episode I feel like when I start I'm kind of nervous I'm not breathing
right and it doesn't sound good at all it's like embarrassing and then after a while I'd start to
relax into it and I start sounding a lot better I'm talking a little more slowly I'm breathing
naturally things are going great so I think the reason for that is because I have warmed up by then
so what I've been trying to do is just warm up ahead of time in this case for example I prepared
a bunch of 3x5 cards with sort of a script and then I just read through it on my own without the
the recorder even running I just read through the whole thing trying to get to this state before I
actually start recording so try that out warm up before you record and then I mentioned the 3x5
cards so when we were talking to when I was talking to Carl I mentioned how back in the day
there used to be apparently a phone number you could call and you could just start talking and it
would record it and it would make it into an episode of hacker public radio later so people would do
that they would just call a phone number and one take they would record an episode of hacker public radio
I think to me that's the standard we need to strive for here because you know in this world it's
pretty hard to make time for things like this you work full time and you know you have your family
to take care of how is whatever else is going on you know there's not a whole lot of time left
for making art or you know making stuff recording episode of hacker public radio so if you can
do it in one take if that's possible at all I want to investigate that and I want to figure out
how I can do that you know so what I'm trying here today is these 3x5 cards I'm so I made them and
then I read through them through one time without recording and then I went back to the beginning
and started recording and and it's pretty good I think I'm still going to have to take it to
audacity but not nearly for as much as I usually do so I think this episode will be finished
much sooner than most episodes have most of my episodes anyway yeah I listened to an episode by
this Mr. Gadgets earlier today and yeah he just called in and started talking and 15
months later he had a show anyway that was pretty much all that I have in closing I just want to say
that none of this that I've talked about matters really as much as just having something good to say
now that may seem hard to have something good to say but here's the thing you do have something
good to say and the easiest way to do it is to just press record with your app or your recorder
or the Dolby on app if that's what you want to do press record and then say hi I'm a new
HPR host and here's how I got here all right thanks for tuning in and come back tomorrow for
another episode of hacker public radio bye bye you have been listening to hacker public radio
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