Hey, I have a question about how to make nice, thick, tough car sounds. I have some good recordings of car sounds and was wondering if there are any good techniques to beef them up and make them sound real.
Well, working on this sound design challenge myself, I found the "Max Bass" and "Lo-Air" plug-ins a godsend on those thin car recordings.
I always add a excite plugin, then pitch shift, and then double.
Distortion can be very useful in this regard. Most car recordings are very clean and need to be messed-up a bit to become believable. Experiment with varying degrees of distortion and see what sticks - each car and each situation will be different. Also, as mentioned before, bass enhancers like LoAir and Rbass are great for adding that nice meaty bottom. And when you're all done with those processes, finish it off with some limiting and see where you end up.
I also am working on the sound design challenge. I beefed my sounds up with Time/Pitch. It can simulate a revving with almost any type of sound.
I find that the harmonic exciter in iZotope's Ozone 4 does the trick on almost anything.
Try some heavily low-pass-filtered pink noise. It might be a bit too rumbly, but if you use it sparingly it'll add a lot of weight.
Figure out the fundamental Hz of your car sounds (hoping you got fairly steady engine or exhaust loops - forget it if you're working with drive bys) and mix in synthesized tones of the same pitch. This is, for technical reasons, probably more applicable to games than anything else though..
Don't be afraid to add some hot rod to your mix... and if you want it to sound vicious, a growl of some sort will blend nicely.