Hearts of Iron IV – Development Diary 51 – Music & Sound Design

Line up soldiers!

Welcome the 51th DD and for this week we will talk (mostly) about the music and sound design:


Hi, my name is Andreas “Jazzhole” Waldetoft and I am the music composer at Paradox.

Now, I have done a few Hearts of Iron’s by now (HoI2 and HoI3) so let’s just say that I didn’t need to research Second World War as much this time around.

However, Hearts of Iron series is the one that is very close to my heart indeed. It was the first game I had scored.

Back when HoI2 was being developed, Fred Wester handled the music (among a lot of other things I presume, as we were not as many people at paradox back then). Fred was kind enough to take me in for HoI2 and let me do the music even though I was still in university with only a few short-films and orchestration jobs under my belt and the rest I guess is history for me… well until I did Stellaris to be fair.

Anyway, As I said, we had some ground laid out music wise from the past games in the series. I have tried to build on that and sometimes reprised a few of the themes from those earlier HoI’s to get the feeling that this is the same game. Only bigger and better I hope.

I am an orchestral composer so being able to write for a large orchestra was the first thing I requested for HoI4.

Funny story though, I went down to record with Brandenburg State Orchestra which is a German orchestra. Same one we used for EUIV main theme. When I came to the music hall, the orchestra leader told me to maybe… not tell the players what the music was for. I guess “don’t mention the war” still holds true in some parts of Germany? We were doing Axis, Allied and Comintern inspired music so I do however think the orchestra knew exactly what was going on. They did a great job in my opinion.

This video is a recording from a sample of one the Axis tracks. It’s not the Main Theme for HOI IV mind you.

And no that is not me conducting the orchestra, that is the brilliant Bernt Ruf. I was supervising it from the studio so I could hear everything more clearly, and I would tell the orchestra through the conductor if something was not how I wanted it.

Hearts of Iron IV OST - Rise of the Axis Powers - TeaserHearts of Iron IV OST – Rise of the Axis Powers – Teaser

The chromatic violin line is my way of trying to give that german-panzer-on-tracks-going-forward feeling. It is used quite a few times in the soundtrack, especially for Axis music. The Tenor and later Bass Trombone’s are playing the theme and snuck in there is also a chromatic passage that references the violins. I tried to orchestrate it in style of German composers that comes to mind from that era.

Sound Design:

Hi guys! If you don’t know I’m Metal King aka The Audio Director here at Paradox. Usually if you work with audio / sound design you tend to be involved with all the projects that are being developed.

For this DD I thought that I should show you guys some “behind the scene” pictures and talk about some the sound effects that I’m pleased with in Hearts of Iron 4:

Propeller / Airplanes:

When I started working on Hearts of Iron 4 we were missing some decent sound effects for all the airplane animations. While I was looking for good audio resources, like actually recordings of aircrafts from the era, but I wanted to have a good placeholder sound so that the team would get a better “feeling” of how it could end up.

Then I noticed this beauty in the “Engine Room”! More know as model “FD-40KI” or as I call it “Metalcraft-666”.


I placed a microphone behind the fans and started to record and the results was so good that I actually kept to the game! Then with a combination between actual recordings of aircrafts from the same era and with my recordings it turned out to be a good sound effect:

Light Plane Entity IdleLight Plane Entity Idle



Found a neat old typewriter at Paradox’s HQ when we had our old office. I took the opportunity to record it so that I could use some of the audio to our GUI. As you see I did couple of recordings where I placed the microphone on different angles. The recording that turned out to be the best was when I had the microphone behind the typewriter, as you see in the photograph.


As a former Foley Artist for Films and TV I wanted to create some audio assets for the walk animations on our troops/infantry to give more “life” to the screen. I wanted to have the sounds of walking around with heavy boots, a lot of equipments and weapons. So what I did, before we got our awesome sound studio, was to build up a “surface” with old vhs tape, cardboard paper, clothes and other “junk” while wearing a denim jacket with a bag full of “metallic stuff” in one of our meeting rooms in the old office and just walking on the same “spot” over and over. People didn’t really understand from the beginng why I was walking around in “junk”..

I’ll end this small part about some of the sound design with a picture of the new sound studio. Spent a lot of time in hear and mixing the game audio to make sure you will get the best sounding experience possible.


This is for this week!