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-   -   Getting good automotive audio (https://www.dvinfo.net/forum/all-things-audio/96821-getting-good-automotive-audio.html)

Chris Rieman June 18th, 2007 11:10 AM

Getting good automotive audio
 
I do video exposes' on automobiles and have rigged a lipstick-cam to get me some decent video for motion shots directly on the car at speed, however Im struggling to find a good way to get quality audio. My hurdles are a) wind noise b) devices to use that I can mount somewhere to get engine sounds.

The lipstick cam Im using has a built in audio mike to it but its useless for this. So that audio track gets thrown away entirely. I would have no problem working a car over for just the audio track. I dont need to necessarily get the audio and video tracks from the same device at the same time. But I do need some reliable setup to get the audio.

I havent found a decent location to mount an audio device (like lavalier?) strung out say through the sunroof and taped down somewhere. What should I be recording the audio into?

Im sure theres an industry secret here on how to make this all work, Im just fumbling for answers at the moment.

Oren Arieli June 18th, 2007 12:09 PM

The industry secret,as I understand, is foley recording (done after the fact). For example, you can record the car revving (while standing still), from a few locations (near manifold, near exhaust etc). Otherwise, at speed, you're bound to get too much noise-to-signal (as you've noticed). You can also try another audio-only pass of the car in motion, but create a baffle that houses the mic and protects from oncoming wind (think parabolic mic). Best of luck, there is always sound fx library clips as a last resort.

Chris Rieman June 18th, 2007 12:22 PM

Yeah I was afraid of that. About the best audio I can get while the car is in motion is just recording ambient engine noise from inside the car using the built in mike on the camcorder. Its not horrible, but you can still pick up wind noise from just the whistling of the car against the air.

I have a ton of digital juice products but have been waiting to see if they firesale their sound fx I and II libraries. I think they have some car sounds on them. My hurdle is Im dealing with porsches, ferraris, and lambos so they have specific sounds and a generic cut of some chevy nova passing by isnt going to fool anyone.

If I recorded cabin audio, do you think an audio mixing software could eliminate the nefarious wind noise and boost the engine audio? I have the freebie version of Acid, but it really doesnt do a whole lot. I downloaded a freebie audio track mixer which is supposed to be really good that a lot of ppl use, but I cant remember the name (Im not at home in front of thatc omputer). If I could do some straightforward stuff to the cabin audio, maybe this is my best bet other than foley?

Greg Bellotte June 18th, 2007 01:10 PM

Hi Chris,

As one of the mixers of NHRA and NASCAR over the years, have tried many mic placements for good car sounds. We end up in the engine compartment a lot, or inside the cockpit or trunk. the big thing as you found is getting it out of the windstream. Proper windscreening and other creative tricks go a long way. lots of foam around the mic, or a zepplin/fuzzy helps a lot. always make sure the mic is secured well. can't tell you how many we lost due to improper mounts, esp. on top fuel dragsters-the acceleration is amazing.

Charles Hurley June 20th, 2007 12:09 AM

Typically what we associate with the sound of a car is it's exhaust. The higher frequency noise of the engine is absorbed by the atmosphere and the car itself. Try mounting a wireless under the car or at the rear where the airflow is least turbulent. You might also try something crazy like using a barcus berry piano pickup/mic/? but that's complete speculation on my part. Good Luck, Charles.

Chris Rieman June 20th, 2007 10:45 AM

interesting. I may try to duck tape my senn G2 wireless to the rear of the car. fortunately most of the cars we do are rear engine so I should pick up engine and exhaust near the same place. If I use the lavalier from the wireless duck taped to the rear, I wonder how I can better protect it against the wind. some sort of shroud around the lavalier mike maybe.

Jack Smith June 21st, 2007 09:36 PM

2 ways I've done this for classic muscle cars.
Imagine the car in a wind tunnel with smoke flowing over it.There is normally a few locations where the smoke curls away from.eg. just above a protruding bumper, under the lip of licence plate hole,etc. Put your mic there pointed toward the car.
Choice 2 works great but may be tough for you to do.
Chassis dyno.
You could try jacking the jack up and putting on safety stands and running thru the gears but no load on the engine it won't sound accurate.
I have also done drive by recording.Putting the mics on a stand and driving past it.

Chris Rieman June 21st, 2007 10:00 PM

Thanks for the advice.

I managed to get some good audio last night. Whether my protocol was conventional from a pro's standpoint of "doing whatever gets the job done" or dumb but worked anyway, it worked.

I used my 911 Turbo as the guinea pig because Im shooting another 911. I have different exhaust and the engines are a bit different, but its close and the body style of the cars was the same.

The rear fender is very flat and serves as a ledge. Of course theres a big tail in the back so air goes way over the fender as it is. I mounted a Senn G2 wireless on the back fender just above the license plate. No real magic here, I just stuck a cloth under it so it wouldnt scrape the paint, then duck taped it down ad naseum. In theory this area received extremely limited air turbulence so the duck tape should do the trick.

I then took the license plate off and ran the end of the lav wire/mike down and duck taped it so it would be in the middle of the lower rear bumper directly behind the license plate. Then I screwed the plate back on. Theres about a 3/8" gap between bumper and plate bracket to run it behind there. I couldnt foresee any other place on the car where there would be less air turbulence.

With the engine in the back, I was gonna get the full orchestra. I had to take the sensitivity down to -30db because my normal setting was getting Peaked big time from the noise and it was mostly static. This slight adjustment MADE ALL THE DIFFERENCE. Keep in mind its real loud back there. Engine 6 inches away and aftermarket dual exhaust.

So I ran the car and things went real well. I got about 6-7min of audio and tried to get all the major parts: low idles, upshifts, downshifts, cruising. The results were very impressive. I monitored the audio through my headphones connect to a GL2 where the other Senn was hooked to (at night, nobody around, no traffic risk).

I now have enough audio to really sample on all kinds of things. 6-7min doesnt seem like much but its something I can re-use over and over and I doubt anyone will ever recognize a clip in the same vid as being re-used anyway.

The only hiccup was when I pulled the duck tape off after getting home, the rear fender gets real hot (remember this is the cars business end) and the tape left that gooey glue type stuff on the paint. Some Goo-Gone took care of it.

So there you have it. If I tried a front engined car, maybe the mode of attack would be different, but I think Id still stick to the rear somewhere near the beltline. But modern cars are smoothing bumpers so it may be harder to find a flat place to put something. Id probably try sticking the Senn in the trunk and running the lav mike out of trunk and to the same license plate area.

No idea if this solution was pretty clever, stupid, or mainstream. But here are the results w/no editing. Enjoy:

http://www.automobilize.com/video/930-engine-fx.mp3

Bill Zens June 21st, 2007 10:59 PM

[QUOTE=Chris Rieman;698560]
I have a ton of digital juice products but have been waiting to see if they firesale their sound fx I and II libraries. I think they have some car sounds on them. [QUOTE]

They just did...On Wednesday (yesterday) they had a one day only sale of SoundFX 1 and 2 for $149.00. You've gotta either subscribe to their website or check it every day for their deals...

Chris Rieman June 21st, 2007 11:11 PM

I ordered it a day or two ago! Also cashed in on a pair of gift certificates. Whoohoo!

George Ellis June 22nd, 2007 07:33 AM

Chris, what you did works. Using someone else's foley audio with your in-car will get spotted by enthusiast in a heartbeat and will loss respect from your audience. They want the real motion with the real car. I am car nut enough to have spent enough hours to have been a SCCA F&C corner captain (National license). It stands out as a continuity problem every time I see in on TV or in a movie.

One step beyond, if you are doing a Front engine car, use 2 mics. Half of the noise of cars like Hondas is the induction sound. Same will apply to others. A 944 Turbo (or variant) with significant boost will stutter-chirp the blowoff valve. Coolest noise a turbo can make (well, the F1 1.5l turbos did the cannon thing out the exhaust - BOOOOOMMMMM!)

Lukas Siewior February 4th, 2009 07:46 PM

Let me bring this thread from dead :-)

I need to wire the car for some racing footage and audio. As video is not a problem with multiple lipstick cameras, the audio is always an issue.

As suggested before, I could use my wireless lav mic to pick up sound from exhaust. That's easy to do. But I have concern about putting a lav mic inside the engine bay for engine sounds. Is it gonna survive the heat? Did anybody try it yet?


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