NashvilleArthur Wrote:Coolness! I've downloaded a few video clips from youtube(one of them with a clip from the Imax "speedway" dvd) and I have a few engine sounds I downloaded from the champcar website. Now I need to know how to make an ICR2 engine sound out of any of this stuff. Any tutorials for this?
It's a lot of trial and error since the sound in-game is never exactly how the wave file sounds in the editor. That said, you need a fairly constant rpm wave at least about three seconds long (the longer the better), preferably in the mid to upper rpm range. You don't want a "redlined" sound sample as this won't reproduce correctly for lower rpms.
Don't ever let the sound level go above about -0.5dB as you can all too easily clip the peaks while processing; I usually do all my processing with a signal level of -3dB to -6dB then, when I'm "satisfied", make a copy and bump it to -0.5dB before saving. If you're experimenting with pitch shifts, never do multiple shifts on the same file; this introduces distortion that increases with each new shift. If you're not satisfied with the results of one shift, start over with your base file. This also goes for any tonal shifts, and be very careful of your levels when using an equalizer - if your base signal is at -3dB and you boost something by 5dB, you've clipped 2dB of signal.
Most live samples include too much extraneous noise, a "brick wall" filter above about 4500Hz usually removes this without affecting the base engine sound too badly; experiment with this, using the highest cutoff possible while still eliminating the background noise. There may also be an excess of "road noise" (from tires, body flexing, etc.) which, while realistic, will not replay realistically in game since it will be changing pitch along with the engine; this can be difficult to eliminate, but experiment with subsonic filters first, moving up to low-cut filters if necessary (I've gone as high as 80Hz trying to clean up some sounds; this may sound drastic but, unless you're creating a GT40 or original CanAm sound, there's very little true engine sound in this range ...modern F1 cars actually have very little below about 300Hz). If you find you need to filter above about 100Hz or below 4000Hz, you should probably look for a better sample as you will be losing some of the base engine sound. (An arguable point: if you want a truly realistic sound from a driver's standpoint, you should filter even more of the highs to give a muffled sound such as would be heard through the helmet, balaklava, and earphones. Personally, I prefer the more open sound.)
A bit of dynamic range expansion also helps, if applied judiciously. Once you're satisfied with your sound, reduce the level to about -9db and add about 5-6dB of linear expansion with a threshold of -12dB. Monitor the levels closely during this stage, peaks can easily exceed 0dB if you're not careful. This will give a more natural sound to the engine, particularly when revving; this will also tend to give you a quieter base sound, resist the temptation to boost it back to "normal" levels - if you're using a program such as Adobe Audition, use its "normalize" function, set to about 96% to make the final adjustment to level. You may have to adjust the levels of other in-game sounds to balance them to this new engine sound, then use your system volume control to "crank it up".
One major problem you'll face is the looping "thump" or "click" caused when the playback jumps from the end of file to the beginning. Don't worry with this until all other adjustments have been made, otherwise you'll be chasing your tail all day since nearly every process will create another looping problem. Once you have the sound as you want, and have normalized the wave, magnify it in the view window and scroll to the start of the wave. If the very start isn't exactly on the center line, find the nearest point that is, place the cursor there and drag the highlight back to the start and hit delete - the file start should now be on the center (you may have to experiment quite a bit here as the editor sometimes won't let you place a mark right where you want it). Notice whether the waveform is rising or falling at the very start; now go to the end of the file and make certain it is also on the center line - but also - moving in the same direction. i.e. if the start of the wave is rising FROM the center line, then the end shoud be rising TO the center line. Visualize connecting these two ends together as one. This can be the most odious part of editing the wave, but any mismatch here will be painfully evident in the game.
