Improving the Sound of iRacing

by Tony Gardner on December 7th, 2011

Although iRacing.com is constantly adding new elements to our online racing service there are always many improvements we would like to make to our current features.  One of those features is sound, which happens to be a very broad topic.

When we think of sounds in a racing game, most of us think of the cars’ engine noises, and that certainly that is a focus of our work.   We have some good ideas on how to improve those engine sounds and add more range.   Of course, our objective is to be authentic when it comes to engine sounds — or any sound for that matter.  That’s why we go to the track and record every car in iRacing, and also do things like taking sound meters to the tracks to measure all sorts of sounds.  In general, any racing sim/game publisher must decide whether to go with “hacked up” special effect sounds or let the real physics drive the audio components.    At iRacing we let the physics drive the sounds, which I guess is a matter of preference between realism and “drama.”  In other words, iRacing will sound different than a “racing video game” unless we move away from physics-based audio.

"'Sound improvements' could mean working on existing sounds like the noise created by crashes . . ."

When we talk about making “sound improvements,” we mean a lot more than simply engine sounds.  For example, we are also adding new environmental and ambient sounds.  Sound improvements could also mean working on existing sounds like the noise created by crashes, the crowd or cars scraping the wall, not to mention spotter messages.  Improvements could also refer to advances in the delivery, mixing and/or streaming of sounds, compatibility with third party products and software, latency, ease of use, adding adjustability and flexibility, access to 3D, supporting various hardware platforms and other audio systems and so on.   Of course, sound improvements could also mean simply adding range and depth to the sounds or adding new effects like echoes in tunnels, making the grandstands “ring” when cars go past or effects like reverb and distance attenuation.  There are all sorts of things that can be done in regard to sound and certainly it is a critical element to your experience in any racing simulation.

“Certainly (sound) is a critical element to your experience in any racing simulation.”

Another large consideration in regard to sound is how you create and then play back the sound, by which I mean the sound “engine.”   iRacing has developed its own proprietary sound engine in this regard.   As most of our members know, we also decided to try and offer a third party middleware or engine called FMOD to create and deliver our sounds from iRacing, and were considering that as a possible long-term “engine.”   We even launched an early stage release of FMOD to members as an alternative sound engine for feedback, testing and QA purposes.

It is important to note, whatever sound engine a publisher chooses, the engine is not magic.  The engine itself does not create any new sounds.   However, it can enable you to perhaps create a “higher end” sound sample or to work with a broader range of hardware and software.

What is FMOD and why did we consider it?   FMOD is a third –party audio product, library and tool-kit used for the creation and playback of interactive audio.  It has an advanced plug-in architecture that can be used to extend the support of a wide range of audio formats or to develop new output types (eg, streaming).  FMOD has many benefits that we hoped to leverage in order to speed-up our sound improvements.  It comes with a full-featured editor familiar to our audio engineer, “Aussie” Greg Hill (not be confused with our VP of Art and Production, Greg Hill.)    It also supports a wide array of hardware and is cross platform-compatible.  And finally, FMOD has a robust set of DSP-based effects that we hoped to take advantage of.

"'Sound improvements" could also mean . . . making the grandstands 'ring' when cars go past."

What have we learned from our test and research?   Like most plug-in software, F-MOD is developed to work with thousands of titles which, in a broad sense, makes it a great product.  However, there are trade-offs in making F-MOD  so widely applicable, namely what is lost trying to get it to work within an overall larger context or a system like iRacing.  There is a level of detail and compatibility that is unique to a particular product, especially a deep product (again, like iRacing) that a plug-in sound engine will not fully address.  In other words, we can’t get FMOD to do what our own sound engine does without even more effort modifying FMOD!

“Whatever sound engine a publisher chooses, the engine is not magic.”

As iRacing’s sound features have improved and matured over the years, they have been tightly-coupled to the physics engine.  As we moved forward on this project we soon realized that at a high level, we were doing things completely differently than the way FMOD operates.  In fact, we were doing things in our own unique way and no third party tool-kit would be able to fill our needs ‘out of the box.’

Without the high level interfaces in FMOD, it was no longer possible to directly integrate their sound editor into our sim . . . and this was one of the main features we hoped to leverage.  In addition, we found that at the low level, FMOD just did not add enough new functionality to justify the large changes needed to our sound system.  In the final analysis, we decided that we can bring over the few small low level improvements provided by FMOD into our own sound system without too much effort.  This will allow us to focus on improving the sound engine, instead of spending time on integrating a new engine, one that would still need extensive adjustments in order to be compatible with our physics.

So although FMOD is a great product, based on our research and actual tests, we concluded that in the long run our existing sound engine will be a better solution to giving our members the best experience possible.  So we are stopping our work on FMOD.

“In the long run our existing sound engine will be a better solution to giving our members the best experience possible.  So we are stopping our work on FMOD.”

One of our excellent software engineers — David Tucker — has been moved pretty much full-time on sound the last few months and is making great progress.  As you are probably aware, recently we improved our crash sounds, cleaned-up the spotter code and replaced missing samples, cleaned-up handing volumes and fixed a bug or two.  Currently in testing we have added 45 new spotter messages, ambient and pit road sounds and body noise, along with a limiter to microphones so those mics that are improperly set-up will not get too loud.

A partial list of our “to do” items includes more spotter messages and better overlaying of messages, placing crowd noises and other ambient sounds based on the actual location of 3D objects (grandstands for example), and adding tire “thump” sound when hitting seams or bumps.  We’re also looking at adding more headroom on our sound mixer (so sounds are not so quiet) along with special effects like reverb, echoes, ringing of grandstands and base thumps when cars are close to you, as well as better ways to handle crash sounds.   Also, we’re adding more user flexibility and control of sounds in order to enable you to add more bass, or just turn-up the sounds for example.

Perfecting the tire "thump" sound is high on iRacing's "to do" list.

Oh yea . . . and make the cars sound better.  In that regard, the biggest change we need to make, moving forward, is to streamline our sound editing process so that our audio engineer (Aussie Greg Hill) can create the stunning sounds he dreams of doing.

When it’s all said and done, the sound system is just a tool to be used and has some limitations.  But with some effort, and a lot of time, we can bring it up to speed and let the talent of the sound engineer come alive.

We have already begun rolling-out these improvements to our sounds to members and will continue to do so in the near and not so near future.  There is a lot of work to do.  But it will be well worth it, as any sim racer knows what a huge difference “sound” makes to the experience and even emotion you get in a sim.

Good Racing!!!