Advice for Automotive High SPL recording

[Phillip C Dent]

So I just caught a job that I would like advice and expertise from the group here.  I have been tasked to record a Ford Mustang GTD going through its paces.  The sound editor has given me a long list of what he wants recorded, both on board the car and outside of the car.  This car generates over 800 horsepower so I'm thinking that it's going to be loud.  The editor wants mics on both tailpipes, two mics inside the engine compartment: one to capture the sound of the supercharger, the other to be placed wherever I think would best capture the best sound of the engine overall.

 

My questions are mostly about gain structure and best techniques to isolate mics from vibration and wind and protect them from heat of the engine/exhaust.  I'm going to be using lavs (both cos 11 and dpa 6060} attached to Lectrosonics sm and mm400 transmitters.

 

My main concern is that the spl's might be too high for the mic/transmitter.  My secondary concern is mounting them in such a way that they don't get polluted by the vibration of the car or the wind passing over them.

 

Any tips and advice would be greatly appreciated.

 

thanks

-Phil

[Rick Reineke]

Dynamic mics typically can handle higher SPLs than powered condenser mics. Shure SM57/58 and Sennheiser MD421 are often used. There are dynamic lavs available as well if size and mounting are an issue.

[Philip Perkins]

I've had this kind of thing go very well and also had it suck.  The former happens when you can get the "car people" on your side and have them be interested in helping you get great sound from their car.  The latter happens when they see you as an extra pain and not important to the people whose opinion they care about.  You can't do anything to a car in these situations without the cooperation and permission from the car folks and the shoot's grip dept.  They have veto power over anything you want to do.  So be friendly, have a lot of mounting choices to offer and be very available when the car is being setup for shots.  It can be hard sometimes to get good info on the car in advance, this requires persistence...   It is also vital to get onto the AD's radar about time to do your work!   I've had the most problems on shoots that had poor internal communications, so that the car people and the AD were genuinely surprised when a sound guy showed up on the shoot day wanting to rig the cars.   Sometimes personal phone calls or texts in advance of the shoot are the best, if only to let them know you are coming.

[Lucas]

I have had a similar job with Porsches on a race track. 

As Philip mentioned above I had the production arrange a car including a driver for me that I could record while the camera team was doing other things. 

 

Having had no prior experience in this specific field I tried several methods that I gathered from colleagues. 
 

The most usable engine sound was from a dynamic mics placed near the engine and one close to the exhaust. 
Some lessons learned in no particular order:

- Engines get hot so use something that does not melt: velcro straps instead of tape for example. 
- You could wrap your mic in a sponge or foam and then velcro ( and double secure everything with tie-wrap) it to something you find in the engine. ( possibilities are car dependent )
- Bring various wind cover options. A collegue gave me a tip to cut two opposite holes in a tennis ball and then slide the ball over the mic having the other hole as an opening for the sound. It blocks some of the wind with high speed but you still need to find the best angle and I still put some foam inside.
- I sat in the car looking at the levels while the driver put the car to it's limits was making me feel very bad... ( so perhaps some recovery time is needed
- also put just one mic somewhere to get some kind of non blown out wind noise.
- If you can sit in the car and have possibility to hardwire you can adjust more easily, if you use transmitters put them on a very low level. 

Good luck!

 

 

 

 

 

[Philip Perkins]

I did a back seat racetrack drive at speed with Bob Bondurant.  To say I was not ready for the G-forces involved would be an understatement--it took me several minutes to recover to the point I could continue recording verite doco sound when the drive was done.  If you can get a good level set with the car not moving consider "dropping a bag" for this kind of thing...

[Phillip C Dent]

Thank you guys for the tips. The sound editor has requested that I put two mics on the rear of the car to capture the exhaust sound. He also wants two in the engine compartment with one of them being near the supercharger.  This for me this is the big unknown for best mic placement. I’m hoping the car guys will help me find a good place for them since this engine generates over 800 horsepower.  I’m using two older cos11s for the engine mics, so I won’t be too upset if they get damaged/destroyed. And I hope there is some L&D in the budget if it happens.

 

I’ll report back how it goes.

[Derek H]

See if you can rent some red mark cos-11 which are 10dB less sensitive. DPA 4061 would be the better choice over 4060. Or even a 4062 but I’ve never used one. 
 

DPA has many very high SPL handling condenser mics to choose from. The new 2017 shotgun for example which can handle 140 something dBSPL   
 

A good 32bit float recorder such as a mix pre II, 8-series, zoom F8N pro or various Tascam models could be your friend here for bag drop situations. 
 

I would have a good deal memo and insurance/ L&D agreement in place with the production company. 

[edward chick]

Being Detroit area based, I have done this quite a bit.

 

Definitely let Production know you need time. I too, have been on both ends of the timeline .. if sfx was planned in the day , they seem chill about it, if it was a last minute client request.. not so much. I have had ADs ask if I can rig the car while they rig it for camera so they can knock off both requests and stay on schedule. It works. Might have to get creative in hiding the mics by tailpipe if they are using a Russian Arm  or pass bys. I’ve used Cos 11s, dpa 4060 high spl mounted underneath bumpers, inside license plate holder, etc,. Engine mounting get with car prep and see where you can safely put the mic and transmitter. Engine electronics may interfere with wireless.  They always do multiple takes, so that’s your opportunity to listen back to your recording and make mic adjustments or level settings. Most times I leave the bag in the car on the floor. If you can get a thermal type wrap for your transmitter that would be an extra precaution due to the heat from the engine block. I think I used a muffler type wrap tape last time from a local auto store. It worked fine. 

Good luck and share back with us what you came up with!

[Wandering Ear]

Most of the time I get usable results with a lav for the exhaust on shoots with an arm car. I have done a few high performance vehicles who’s exhaust is way too loud to record on a lav/transmitter setup. For those my favorite mic is a large diaphram dynamic like a kick drum mic.  If I can’t find a place to mount it while filming I ask for a sound only run that allows me to put mics outside the vehicle. I have had very little pushback with that request. 
i prefer a placement off to the side of the tailpipe and not directly behind it. It gets a deeper sound without any of the air turbulence noise. If the vehicle is travelling at speed I will sometimes create a wind tube using 1/4” neoprene stuffed with fur.   Recently I used this technique on a group or Harley’s riding at freeway speeds with great results and no wind noise. 

[acdave]

Wandering Ear,

Got any photos of the 1/4" neoprene wind tube rig or your other car audio rigs?

Thanks!

[Phillip C Dent]

Just wanted to report back on how the recording of the Mustang GTD went

 

Before the shoot I had a Zoom call with the sound editor.  We discussed what he was wanting to capture, microphone selection etc.  I was pleased that this discussion happened before the shoot instead of having the uncomfortable post shoot conversation about why didn't you deliver...fill in the blank.  He sent me quite an extensive list of what he wanted recorded.  The list was quite ambitious but one of the execs promised that we would get the car for an entire day to record the sound and said that he would be there to make sure it happened.  On the day of the shoot he was nowhere to be found.  So then we were told that we would have the car for four hours and access to the track.  The problem with that plan was that the track closed right after we got access to the car.   We got a couple burnouts on the track but the "car guys" there were not happy with the burnouts and wanted to tune the car to get a better performance.  We got what we got and moved on.

 

They moved the car back to the garage where I rigged up the car with four microphones - two over the tailpipes and two in the engine compartment.  I used DPA 6060s over the tailpipes covered in an Ursa foamie and a Rycote microcat.  I ran the wires into the passenger compartment and taped the power supplies wherever I could.  I used Sanken cos-11s inside the engine compartment and also ran the wires into the passenger compartment.  I hopped into the passenger seat and read out my "shot list" to the driver of what the editor wanted to capture thinking that we would have access to the track.  The driver was fantastic and just said, "OK"   We began to haul ass on the city streets around the track.  Thankfully this track is located in the desert and the streets surrounding it were mostly traffic free.  While the driver pushed the car through its paces, I simultaneously tried to manage the levels while also realizing what a treat it was to be getting a ride in such a high performance vehicle.

 

Thanks to all who offered expertise and advice.

 

 

 

 

 

 

[inspire]

Since the topic is about automotive recording, I thought I’d share some of my own work for comparison. These recordings were made under slightly different conditions – outdoors, right next to the starting line at a drag racing event, where cars were launching. Most of the time two cars started side by side, but occasionally some ran solo.

Processing is quite time-consuming, since the levels are extremely high and require a lot of attention in post. It’s a pretty big challenge, and I’m really curious to hear some examples from inside the car once you get to that stage!

My recordings aren’t all up yet – I’m adding clips gradually, as I get through the hours of raw material. Post takes quite a bit of time, so what I’ve uploaded so far is by no means everything.

You can find my examples here on freesound.org as a dedicated pack: https://freesound.org/people/inspire153/packs/44252/

[Wandering Ear]

On 9/13/2025 at 6:40 PM, acdave said:

Wandering Ear,

Got any photos of the 1/4" neoprene wind tube rig or your other car audio rigs?

Thanks!

Ot looks terrible, but it works. Inside the neoprene is a piece of fur, and it’s held together with black paper tape.