Previous instalments in the Horizon series have been burdened with much-maligned engine effects, unexciting exhaust notes and particularly lifeless off-throttle tones. The latest Let's Go! stream from Playground Games gave us a deep dive into the aural overhaul.
Horizon 5 audio library
Playground Games lead audio designer Fraser Strachan and creative director Mike Brown gave us a peek under the hood at the new way they have been capturing car audio for Forza Horizon 5.
Horizon 5 will have the largest launch car list of any Horizon game yet, with each car having a unique engine note. Over 320 cars were individually recorded over the last three years and added to the existing sound library, with each car mounted with a minimum of eight microphones to capture every detail.
Cars were borrowed to run up and down a disused airstrip, enabling the PG team to capture the full rev-range of every vehicle. Previous methods involved running cars in a garage on a dyno which meant that lift-off sounds were largely simulated. The new, more realistic method, enabled a much more complete capture of all the sounds the engines and exhausts generate.
The developers reported losing a number of microphones to spits of flame from borrowed Supras in the process of trying to capture the perfect exhaust note.
The Horizon team had previously developed a hybrid looping technology with granular synthesis but this was only used on around 10% of cars in Horizon 4. This innovation will be used on every vehicle in the new game.
Thousands of audio files have been captured and will be synchronised with the game at 90 frames per second. The audio will be matched to the engine rotation too. That measn cars feel more responsive when you press down on your controller trigger or pedal. Cockpit impulses have been measured using frequency sweeping sine waves so that in-car perspective sounds reverb in just the same way as the actual vehicle. This includes ambient and external noises, tyre screeches, weather, everything a driver hears.
Xbox Series X and S consoles have a new audio compression format which enables higher fidelity audio and Horizon 5 will make extensive use of this.
Whether it's ambient noise, music, dialogue or the cars themselves, everything will sound more lifelike on the latest Xbox. Dolby Atmos users will also be excited to hear three-dimensional audio effects, with Mike and Fraser particularly drawing attention to the change of sound when retracting the roof of convertibles and also new developments with 3d sound from echos, enabled by ray tracing.
Attention to detail
Every car you come across in the Mexico of Horizon 5 will demonstrate these improvements. Both the AI and the other human players will be enhanced when it comes to engine and exhaust notes, right down to the detail of car upgrades and the environmental factors.
Every material in the game has a sound absorption coefficient, meaning that hiding behind structures in the Eliminator will be audible to other players. As you drive through canyons you'll hear a slap-back echo of your engine sounds from the walls. Tyre noises now depend on many new factors, such as the type of tyre and the sizing, so you'll hear your burnout squeals will vary car to car.
A brand new modular sampling system intelligently pulls from a library of sources for the correct engine sizes and types. From turbocharger whines and supercharger screeches, you will hear whatever is appropriate for the vehicle you're driving.
Tuning your car takes on a new meaning as you can rev your engine while making changes in your garage. You really can compare the sound of any engine swap or performance upgrade to your machinery.
Speaking of which, Mike Brown confirmed over 500 new engine swap possibilities so that there's plenty of variety for upgrades which should make more sense for each car. When you're tuning to go racing, every vehicle won't end up with the same old V10 engine sounds anymore.