Recording a car engine as it goes 0-60mph.

[AlanSound]

Hey everyone!

I'll soon be working on a promo for a major car manufacturer and have been asked to record the sound of an engine as the car goes 0-60mph.

I've only ever done this on a narrative shoot where the camera perspective was inside the car, but this time we need the perspective of a follow car (without getting too much of the follow car's engine of course)

I'm allowed to be in either the picture car or the follow car and we can also see the microphones if necessary, but the clients would also like an option where the mics are hidden.

Another mixer mentioned taping a lav under the hood, but all of the heat makes me wonder how well any adhesives would work.

I had a couple ideas of my own, but instead of reinventing the wheel, I thought I just ask around here since I'm sure someone has done this before. Anyone willing to share their technique?

Thanks in advance!

-Alan

[RadoStefanov]

What engine?

[rcoronado]

We had a vehicle recording rountable with Rob Nokes, Watson Wu and Max Lachmann a while back.  Lots of great info in there:  http://tonebenderspodcast.com/025-vehicle-recording-roundtable/

 

I also just came off a record of a set of Porsche 911 GT3s on the track.  It was a pretty extreme experience.

 

You're going to want to cover these elements: The air intake, the transmission, the exhaust

 

In most cars the air intake is under the hood.  The air intake is where you get that energetic upper mid revving sound.  Lavs or boundary mics under the hood work well in those spots.  Be aware that there IS air moving around under the hood, so place mics accordingly.  You can often zip tie mics to existing structures in the car here.

 

Transmission is typically under the car and often sounds like a big clank.  Smallish SDCs work well there.  Just be sure to attach them securely to the chassis using bungy cords and use towels to do any mechanical isolation between the mics and the chassis.  Drafting is also key here.  Place the mic in such a way that the part you're attaching it to blocks the wind.  You'll have to compromise placement to do this, but its the only way to capture it.

 

Exhaust is the most important and the trickiest.  Exhaust notes tend to be low to midrangey, and sound best when recorded from multiple perspectives, so cover this with 2-4 mics if possible.  I've found PZMs on the bumper to work well, in addition to SDCs gaffer taped securely to the bumper.  MKH50 is great here.

 

Expect to spend about an hour placing and mounting the onboard mics. 

 

You're not going to have many options for getting the exhaust note with invisible mics.  This is because all of the sound is shooting out behind the moving car.  That means you have to have a mic in a spot where the car blocks the wind but not the sound.  Rear bumper is pretty much the only option in most cases. 

 

Booming from the follow car won't work due to wind.

[dfisk]

I've done this a bunch for lots of different exotic cars. 

 

The down and dirty way is just 4 tracks, if the amount of equipment is an issue. One on the intake, one at the firewall, two on the exhaust. Every car is different in terms of where you can mount things, so having grip equipment is handy, along with piles of foam (I like to have the pick n' pluck foam from the pelican cases) to wrap mics in, zip ties, paper tape, and lots of other stuff. I like to use lavs in the engine compartment and a 57 and 421 on the exhaust when the car is on the track. If they have budget, get a dynapack with a dynapack operator and you can get lots of great stuff under extremely controlled conditions. 

[AlanSound]

Wow! Thank you all for such thorough responses! It seems that micing vehicles is quite an art all on its own.

I don't know the exact car yet, but based off of the manufacturer, it will most likely some sort of luxury sports sedan in the 300-350 horse power range. Nothing exotic.

I just got done listening to the Tonebenders podcast. Thank you so much for linking that as it was indeed a wealth of information!

Since I'm pretty sure this car recording was an afterthought to the rest of the job (I was originally asked just to do sound for interviews and some b-roll of the cars), I doubt they will be willing to shell out too much for extra rentals. This is my plan based off of the mics that I currently have:

Under the hood on air intake:

Sanken cub 01 (and an sm58 if I can fit it)

Under the hood on the firewall:

Sanken cub-01 or a Cos11

Under the car focusing on the transmission:

Akg ck93

On the rear bumper for the exhaust:

Crown pzm placed sorta close to the exhaust and a ck93 placed further away

For the mics on the bumper, I would love to add wind protection, but what is the best way to cover the crown pzm? I've only ever used conventional methods like softies and zeppelins.

I do have a few sennheiser 8050s I could use instead of the lower quality ck93s, but since the 8050s are incredibly delicate and very susceptible to handling noise, they don't seem like the ideal choice.

The podcast recommend cutting up a fire blanket and using the pieces to cover the mics under the hood. Would you guys recommend covering the mic completely or leaving a but exposed for fidelity? I also plan to cover the thin cub-01 wires since I doubt they can take much heat.

I'll also be picking up some neoprene and foam for mechanical isolation and a bunch zip ties and bungies for securing. Everything gets run via xlr through the passenger window into a 788t.

Did I miss anything or does this seem like a viable plan?

And thanks again everyone!

[rcoronado]

Hey Alan,

 

Overall your plan looks pretty good to me. 

 

the interesting thing about miking fast moving vehicles is that if you're drafted correctly, you only have to worry about crosswinds strong enough to break the wind "barrier" created by the car itself.  Once your car gets up above 30 or 40 mph, you're pretty much sitting in a bubble with regards to wind hitting the mic.  This means that minimal wind protection is required to the mounted onboards.

 

when I recorded my motorcycle back in the day I only used one layer of towel on the SDCs, and literally two layers of Tshirt on the PZM, secured with gaffer tape. 

 

pics and recordings here.

 

side note - how do you like those AKG mics?  the fig 8 option they have is the cheapest real fig 8 out on the market these days.

[old school]

The car is the star. They won't allow your cables and rigging to show. I almost always do my fx recordings with out the camera. Usually at lunch or some time when the car is not being used.

CrewC

[AlanSound]

Hey Rene,

The breakdown of how you recorded your bike was very helpful (and pictures are always great!).

I see what you mean by the importance of drafting. I'll try your towel/t-shirt approach.

As for the akg mics, I'm not a huge fan of them. They were my original hyper cardioids for getting dialogue indoors, but they are not terribly sensitive mics and have a noticeable noise floor. If you get a quiet talker, you are kinda out of luck. They rarely get used ever since I got my 8050s. For non-subtle sfx though, they are great since the reduced sensitivity cuts out a lot of the room noise and reflections but still has a lot more detail than a dynamic.

I come from a narrative background, so my knowledge of ms-stereo is pretty limited, but every so often I'll work with a boom op that has a music background and they love using the figure 8 capsule (ck94 I believe) and my cs3e to record atmosphere. Over all, I'd say the akg mics are "good enough" but there are certainly better out there.

[AlanSound]

And thanks for the heads up Crew. Despite being told that I can have visible mics, I wouldn't be surprised if their coordinator was simply misinformed.

[AlanSound]

Hey everyone,

I was hoping to give an update after the recording was done just report back on how it went, but I was just notified that the client has canceled the SFX portion of the shoot.

Thanks for all of the help though, as this has been a wealth of knowledge that I'm sure will come in handy down the road.

Thanks again,

Alan K

[rcoronado]

aw, bummer!  I was looking forward to hearing the story.