Hi guys! I'm a long time gearslutz forum lurker but first time poster, hopefully with an interesting conundrum!

Recently I've been doing a lot of sound recording jobs with cars and I'm struggling to find mics that are up to the job of being mounted next to the exhaust. Obviously this is an area of extremely high SPLs and it often gets pretty hot down there so the first thing I tried was a good old sm57. Whilst being able to not clip the recorder I'm quite certain the mic itself clipped upon reaching the apex of acceleration causing a really muffled low-end rumble. What I'm really after is a snarling, growling beast so this is just no good!

Anyone know of any mics that may be good in these extreme environments??
Cheers!

first off, the manufacturers SPL ratings can be decieving for many reasons, and none of them can in anyway estimate when damage could occur to the element or capsule. all that to say, you may want to start with something that doesn't cost a bunch or have particular value to you.

If you're recording the car in a garage per se, you could get away with using a condenser, but if youre right on the engine/exhaust, Id personally go for a dynamic. They tend to handle high SPL well, and its typically harder to damage a moving coil than a ribbon or capsule in my experience. I seem to remember someone mentioning they were recording gunfire with a beyer m201 with good results, using an inline pad (between the mic and the preamp, a shure one if I remember correctly.) You might also experiment by padding the hell out of a condenser and using it as an enviroment or room mic (or garage mic??) and a dynamic closer to the source. I was doing some audio for a film once, and they wanted the turbo charger to be very prominent in the mix, so i put a 421 in this instance with an inline pad close to the turbo charger, and a 414 (max pad) over the rear of the car about 4 feet up (it wasnt actually moving). I think there was some RODE shotgun mic mixed in there too from a further distance.

it sounds like the proximety effect for them mic on the exhaust is just too much for the 57 in your instance to handle, Id try moving it back some so that you can at least overcome the inherent proximity effect.

AN omni dynamic may be worth a try.

If the car was moving with the mic attached, your rumble is probably wind buffeting. A zeppelin may help...



-tINY

Very true! SPL testing with a 1K sine really does mean nothing in the field- I'm very much more interested in other peoples experiences of recording sources with high SPLs.

The garage recordings aren't much of a problem, a couple of well placed M66's with a tactical NT5 or two for good measure generally seem to give a good sound and a few nice options in post.

Its capturing a constant sound of the car engine in motion that's the trouble. The guys I'm working with do a lot of shots from the back of a tracking car and after one session with a boom operated shotgun mic alongside the polecam it became obvious that the car needs to be rigged to get a decent sound.
An NT6 capsule in the engine compartment works a treat but obviously doesn't get the growl from the exhaust... I do have another NT6 but I wasn't really willing to take the risk mounting it so close to the exhaust... dont mind loosing a 57 so much! (as it turns out the 57 returned from a trip around the racetrack unscathed!...I half expected it to melt!)
An Inline PAD is a great idea, I'll have to invest. Great Idea about the 421's- I've seen a few videos of people recording gunshots with them so that could definitely be an option. As for the bayers I'll have to do a bit of research.

Ahh of course, proximity effect would explain it... however it was very strange the way that up until a point, the mic sounded great. Then, as the car RPM increased, the mic suddenly lost all top end. Unfortunately, the mic was clamped to the inside of the rear wing, space was a premium and the mics had to be hidden in the bodywork for the aesthetics of the film so moving it back wasn't really possible.... saying that, a (very) robust omni condenser would do away with the proximity effect all together so that may be worth trying out... carefully!

I'll definatly try a 421 next time and look into getting my hands on a bayer m201. Thanks very much for the advice!

Very good points, wind is most likely the culprit! thanks very much *scuttles off to the workshop to fashion an inflammable windshield*

Heil mics are worth looking at. Otherwise there are some Shure mics with switchable pads which will take up to 165dB input.

What would y'all think of an e604 on a sport bike exhaust? I'm wanting to rig up my bike for a video, and I'm trying to think of small microphones for a low profile setup and wire everything into a field recorder tucked away into the tail cowling.

seriously?
you want to trash a 100$ mic for a motorbike video?

Well I figured it'd be easier to replace than the 400-500 dollar mics these guys were talking about earlier. What would you recommend?

sorry, I'm afraid I have no recommendations for this sort of task.
good luck.