Thread: Recording Moving Cars... Advice

It's a good question. With a mono mic, there is no "pan" of the sound, as that term refers to the movement between channels in a stereo sound field. In mono, the sound is always centred, so tracking the movement of the car with the mic makes no difference to the spatial effect. However, if your mic has a directional pattern, i.e. is not an omni, the thing that you would gain by tracking is a fuller representation of the Doppler pitch change as the cars go by. At legal urban speeds, this is a small change, but is perceived subjectively. It would be more noticeable on emergency vehicles travelling at higher speeds and using sirens.

What you should be using is a stationary stereo mic set. I occasionally go out and sit lineside to record steam train special workings, and for that I mostly use a spaced pair of small diaphragm condenser mics on stands with omni capsules fitted. Despite the omni capsules, I still need windshields even on a still day because of the air disturbance caused by the train passing. I also take a secondary recording on a Zoom H4N recorder using the X-Y built-in mics, but it's much more difficult to get a satisfactory result with a co-incident pair and a very wide sound field.

The other factor in your case is whether the vehicle is the only sound source in your recordings. If there are other prominent sounds, it makes sense to have the microphones stationary (not tracking the vehicles) to keep the other sounds where they should be.

Thank you Boswell for the detailed thoughts. Lots to learn. I'm gonna play and see what I come up with.

Chris

You could even generate your soundtrack in a cinematic fashion. That would be recording some basic background ambience. Then through utilizing Foley technique, you could record cars passing in Mono or, in stereo. Then you put your mixing chops to work for you. You're painting images with sound. So you'll be automating your pans in short order digital delays to create Haas and Doppler shift sound, for the vehicles that are passing left to right, right to left, toward and away from you. Something approaching you would go from a mono signal, split to two channels out of phase, to 2 channels, Mono, in phase for an approach. In reverse would utilize the same technique in reverse. So you can create a car chasing away from you complete with a stereo perspective. That and some algorithmic ambience generation. And then you're cooking with gas or is that gasoline? Which really does a horrible job on the barbecue chicken. Yuck... Or should I say cluck? Just don't add too many peckers. But I digest... it's almost 4 AM and I think I forgot to eat today? I can't start the barbecue up at 4 AM? And the microwave really doesn't cut it.

Oriental rice noodle soup. Just add boiling water.
Mx. Remy Ann David

Now that's Italian!

I recorded many of the car and traffic sound effects found here: Traffic Ambience | Rocksure Soundz . I used a variety of different methods. In some cases I used a spaced pair of cardioid mics to capture the pan from left to right. In some cases I used a single mic and recorded in mono, kept stationary, or by following the vehicle from left to right or right to left. In other caes I recorded a general street ambience, and then added the mono recording of a car and panned via automation into the sound of the general ambience I had recorded with a stereo pair. Sometimes it's multilayers of cars. In the end, it's the perception to the listener that is the main thing, rather than how the effect has been gotten that matters most.

Tony's talking about actual mixing technique performed all the time for the movies and your favorite TV shows, music videos, all that stuff. That's why we are audio engineers. We construct and build audio. From whatever sources and whatever tools you have. You bring it all together throw it in with some pot... of other audio soup and voilą. Real live sounding NATURAL captured sound effects, mixed together by professionals.

I always wondered how they got those hydrogen bomb blasts?
Mx. Remy Ann David

They actually got them with B & K's, on top of a bunker because they also had to know precisely how loud they were. And they were making microphones for military government testing purposes. Which is what a friend of mine has been doing at Aberdeen proving grounds for over 30 years now. I never knew the military had bombs designed to have some go boom louder or softer than others along with sonic booms, jet engines and other things I guess that are still classified? That I know are still classified.

In an unrelated but similar story (everybody knows I love to tell technical stories) I had my remote truck parked in an industrial center here in Northern Virginia. Next-door was BAE systems, a defense contractor. Across the street is General Dynamics. Another block rover is Northrop Grumman. A block from them is Lockheed Martin and then we also have Boeing and Orbital. So I'm sitting on this empty street at a red light. Flying over top of the General Dynamics building I see a F-15. It looks to be unstable? It most definitely is having control and maneuver problems. It just banked over. It looks like it's lining up coming in for an emergency landing on the street I am sitting on? No... no... OMG! The light is still red and I'm disconnecting my safety belt to prepare to jump out of my vehicle! When it banks back around and lands in the General Dynamics parking lot? WTF? Saturday afternoon... empty parking lot except for a couple of cars and this guy flying jet powered radio controlled, fully functional model aircraft. Complete with retractable landing gear. Scared the crap out of me! And I watched his MIG 29 burst into flames, crash and burn or was that burn and crash. He had a whole slew of these jet powered model aircraft and worked for General Dynamics. And they didn't invent the F-15. They invented the F-16. He had one of those also and a Grumman A-10 Warthog. And these things were large! Most of the size of the bed of a pickup truck. They weren't little toys. They were big boys toys. He also had an SR 71. All of this was in an automotive carrier trailer connected to the back of his Hummer. So I was also privy to an awesome airshow, since I drove across the street once my heart started beating again to talk to him.

They don't even sound like model aircraft. More frightening to have coming at you than any drone. And the details are just totally amazing. He also had some lithium battery-powered electric jets a.k.a. ducted fans. They also didn't sound like model aircraft. They were just too real.

Look out!
Mx. Remy Ann David

Originally Posted by RemyRAD

They actually got them with B & K's, on top of a bunker because they also had to know precisely how loud they were. And they were making microphones for military government testing purposes. Which is what a friend of mine has been doing at Aberdeen proving grounds for over 30 years now. I never knew the military had bombs designed to have some go boom louder or softer than others along with sonic booms, jet engines and other things I guess that are still classified? That I know are still classified.

In an unrelated but similar story (everybody knows I love to tell technical stories) I had my remote truck parked in an industrial center here in Northern Virginia. Next-door was BAE systems, a defense contractor. Across the street is General Dynamics. Another block rover is Northrop Grumman. A block from them is Lockheed Martin and then we also have Boeing and Orbital. So I'm sitting on this empty street at a red light. Flying over top of the General Dynamics building I see a F-15. It looks to be unstable? It most definitely is having control and maneuver problems. It just banked over. It looks like it's lining up coming in for an emergency landing on the street I am sitting on? No... no... OMG! The light is still red and I'm disconnecting my safety belt to prepare to jump out of my vehicle! When it banks back around and lands in the General Dynamics parking lot? WTF? Saturday afternoon... empty parking lot except for a couple of cars and this guy flying jet powered radio controlled, fully functional model aircraft. Complete with retractable landing gear. Scared the crap out of me! And I watched his MIG 29 burst into flames, crash and burn or was that burn and crash. He had a whole slew of these jet powered model aircraft and worked for General Dynamics. And they didn't invent the F-15. They invented the F-16. He had one of those also and a Grumman A-10 Warthog. And these things were large! Most of the size of the bed of a pickup truck. They weren't little toys. They were big boys toys. He also had an SR 71. All of this was in an automotive carrier trailer connected to the back of his Hummer. So I was also privy to an awesome airshow, since I drove across the street once my heart started beating again to talk to him.

They don't even sound like model aircraft. More frightening to have coming at you than any drone. And the details are just totally amazing. He also had some lithium battery-powered electric jets a.k.a. ducted fans. They also didn't sound like model aircraft. They were just too real.

Look out!
Mx. Remy Ann David

Far out! That would have been impressive...and no wonder you got a fright!!!