Tyre Textures

WARNING: This post starts off well and then ends on a bit of an Indiana Jones based tangent

Currently I'm working on a book which will be available next year called The Game Audio Tutorial. The book is going to be a guide to all things game audio and features some examples of car audio. For this I needed to create a selection of short loops to be played when the vehicle travels over different surface types.

Setup was pretty simple, I took the boom arm off a mic stand and mounted it between the wingmirror and window with an old towel zip-ties and duct tape.

Here's a couple of examples of what I recorded;

Recorded at 192k 24bit with a Rode NTG-3 and a Fostex FR-2

Recording this is relatively simple either get up to speed or start on top of a hill (best method) switch off engine and roll down trying to maintain a constant speed.

Couple of safety tips;

  1. Switching off the engine in most cars disables power steering and makes the brakes really heavy so make sure the area you are in has plenty of run off and is fairly straight.
  2. I imagine the police would take a dim view of you doing this if they caught you so either find a private road or a really really quiet one.
  3. Make sure the mic is strapped on properly I wouldn't fancy running it over or leaving it in the middle of the road for someone else to run over.

Quick Editing Tip;

The recording setup above and other D.I.Y. stuff I have done can produce results that won't loop properly as there can be slight modulations in the pitch or speed of the car.

To make them loop I have been using a quick little trick.

  1. Edit a section as normal trying to keep the loop as regular as possible and make it a little bit longer than necessary.
  2. Export selection to new file.
  3. Split the new file in to two separate waves around the midway point at a zero crossing.
  4. Take the second half and move it to the beginning of the loop then move the first half to the end of the loop.
  5. Now cross fade the two files.
  6. You now have a file which may modulate but will perfectly loop.

Couldn't really talk about this without mentioning one of the great uses of this; (3:50) The giant boulder that chases after Indiana Jones at the start of the film was made of fiberglass. On the Bonus Features DVD, sound designer Ben Burtt said that in order to get the proper sound effects for the giant boulder, he and the sound crew tried pushing boulders down a hill, but the sounds they were getting weren't up to par with what they were looking for, and later that day, as they were leaving in a Honda Civic that they coasted down a gravel embankment, Burtt noticed that the sound was just what they were looking for, so he grabbed a microphone and held it near one of the Civic's rear tires to record the effect.

I was looking for a video example of this and came across a two part sound design feature on the Indiana Jones films so here they are in their entirety;