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Hello, as a car nut, photographer, and 3d/2d visual effects artists, one thing that I've always wanted to do is be able to record decent quality audio of car engine sounds to sink with video. (or also to be used as audio to be mixed into other video)

I was on set for a car shoot a few months back and I watched the audio guy place a few small little mics in various places on the cars. I really liked the quality of the sound files that were recorded on the intake and exhaust of the vehicle, it had a nice throaty engine sound from the intake, and a very raw engine sound from the exhaust mic, and they sounded very good when mixed together in with the cabin and external mic. I'd like to get a relatively inexpensive setup that would give me decent results, I'm not expecting to get audio on par with professional audio guys, but I would like to get better and more area-specific (so I can mix them) than what a hand-held video camera would get.

So, I'm looking for a setup that I can record from multiple positions, probably 4 positions: intake, cabin, exhaust, and then hand-held next to the recording camera. If they could record wireless, that would be wonderful! My consern is that I'm imaging most inexpensive setups may not be able to handle the very loud noise of some modified V8 cars when they are placed in the intake or near the exhaust. The hand-held mic I'm not really worried about. The car will be in motion at speed, but I also may do a few things while on a chassis dyno, but usually on the open road.

Does anyone have any suggestions for a set of small mics that could handle loud sounds? Also, what would be some inexpensive options to record multiple mics at the same time? (or would I need multiple recorders?) An all digital setup (on flash cards or something?) would be ideal for me, I think.

I'm not really sure what my budget is, I'm more or less looking to see what particular setups would cost. Starting at a low-end setup that would get the job done decently.

I'll be mixing the audio together in Adobe Audition and AfterEffects that I have access to at our visual effects studio at work. I used to use a program called CoolEdit years ago (despite the cheesy name, actually seemed to work fairly well), which I believe has turned into present day Adobe Audition, so I shouldn't have any problem figuring that out.

Thanks for any info and input!

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RemyRAD Mon, 11/10/2008 - 15:39

Will you have certainly thought this out very well. Of course you had some exposure to quality audio.

Here's a general rule of thumb to remember. Dynamic microphones, those that use a diaphragm with a coil of wire & a magnet, such as the venerable Shure SM57/58 don't/can't overload. They are passive devices that can still output quite a bit of level. It's the input preamp that overloads. And most people don't understand how to deal with that. The sounds at your recording of the engine at the intake & the exhaust isn't much different than trying to record the inside of jet engines. Right. You're obviously going to need something fairly specialized to capture this in a quality way. You're not going to need high gain preamp's, that's for sure. For sure for sure.

And you probably don't want to screw up a $100 Shure SM57 or 58 by sticking it up some asses car ass. No. So, what kind of microphone? One should know that the smaller the capsule of a condenser microphone, the less sensitive they are. So what I might suggest is inexpensive Radio Shaft $20 lavalier, "Thai tack" microphone. It utilizes a single AA battery and has an unbalanced output. If the cable length is not made any longer than 10 feet, you could easily run this into a ZOOM H4. So you can probably keep the recorder in the car cabin with 10 to a maximum of 20 foot unbalanced cables. If the microphones get destroyed? You can LOL since it only cost you $20 and not $100 nor $1500. The recorder is a couple hundred dollars investment. But with the convenience of recording to flash memory, you'll be making some great sound effects. Wireless? You could but why? Don't even think about wireless. Now you might think that the Radio Shaft microphones may not be adequate? OK, replace the AA battery with the hard to find 6 volt Eveready battery, that is half the size of a double-A battery so you need 2. They're not cheap. Something like eight dollars per battery? But it will gain you lower noise, higher headroom, better performance. Remove them when not in use as they will drain with the switch off. Just know that the capsule in this $20 wonder, is made by the same Taiwanese company that makes most of those other manufacturers inexpensive "Studio Condenser Microphones". Crown uses them for their microphones. Yeah, the same company that Radio Shaft also buys from in Taiwan. So you're getting a Crown quality condenser microphones that just wasn't tested or marketed by them.

On the inside track
Ms. Remy Ann David

anonymous Mon, 11/10/2008 - 16:31

Thanks for the reply Remy!

I am happy to see a $20 item suggested! That will easily be a good first-test item to be put close to the loud engines! I don't think any of these cars would be even 1/2 as loud as a jet engine, but I think I get your point! The loudest recording (exhaust) won't actually be inside the exhaust, but more likely on the rear bumper somewhere

A Dynamic mic is what I'm looking for then? sounds good, thank you! These cheap lavalier mics, they are Dynamic I assume? I don't quite understand what you mean by the unbalanced output of the AA battery. The doubled-up 6 volt battery you are suggesting, is this to correct that unbalanced output? You say lower noise, are you talking about electronic noise? Will that matter much to me, since I'm recording things that are loud? Either way, $8 per battery ($16 per mic) wouldn't be bad, and I assume they would last several sessions at least?

You mentioned the input preamp, is this something that is usually built onto the recorders? or a separate device before the recorder? It appears that I have some learning to do (y) I'm looking forward to it though.

As for the recorder, I see you mentioned a ZOOM H4. I see it listed for about $300, that price does not scare me (thankfully!). I did a search on that, and it seems to say that it's a 4 track recorder, but I'm looking at photos of it and I only see 2 inputs. So, I am guessing that it only records 2 tracks at once, but lets you play back 4 tracks together? Unfortunately, I need to record 3 tracks at once (and if done wireless, all 4 tracks at once!). 3 of the tracks on-car, and the 4th track outside the car next to the camera. Can you recommend a recorder that can record the 3 on-car tracks simultaneously? I can sink that recorder with my camera and external mic with a clap. I like the sound of recording .wav files directly to a memory card, no need to 'capture' anything, just load up the files! I think something like this will work wonderfully, if I can record 3 tracks at once.

The reason I was thinking about a wireless solution is because I'm not sure how easy it will be to route wires into the engine compartment for the intake and around to the back of the car onto the bumper to get the exhaust. Are wireless mics not as reliable as a wired mics? Or are they to much of a hassle to bother with? Or just more expensive?

So for the basic recording setup that I'm looking to do, I need the mics, and the recorder. Is there anything else that is needed? If nothing else is needed, what about other additional devices that would/could yield better results when utilized? (like the preamp that you mentioned?)

Thanks again for your reply! Forgive me if some of my questions are basic, I have only dabbled in audio recording (and hope to pick-up dabbling again, haha!)

anonymous Tue, 03/10/2009 - 00:13

I got a little distracted by some photography projects, so now I'm back thinking about audio again, especially since my car is back on the road now! hah!

So, I'm looking for some suggestions for the heart of my setup, the recorder. Does anyone have any suggestions for a relatively inexpensive recorder that can record to digital memory (Flash/SD or the likes?) and one that can record 3 mic inputs all at once? I looked at the ZoomH4, and even though it says it's 4 track recorder, I only see two inputs. I would prefer to have 3 inputs if possible.

I'm not really sure what types of features I want, my main concern is that the loud sounds don't get 'clipped', which from what I think I now know is defendant on the Mic, as well as the input gain being set low enough? Will most recorders be able to turn the input gain fairly low? Or is this something that I don't really need to bother worrying about since maybe any recorder would be able to handle it?

jg49 Tue, 03/10/2009 - 04:22

The newest addittion to the Zoom line is the Zoom H4N 4 Track Portable Digital Recorder. It does allow simultaneous 4 track recording. 2 external mics, which you could use as Remy described above for the intake & exhaust, as well as two built in mics (one stereo channel) which could be used for inside the car. You will just have to toy with where exactly you place the recorder in the car to get the best sound and avoid vibration transfer to the case (for example you might want to place a folded terry cloth towel under the unit.)
Another choice would be something like this, Fostex MR8HD Digital Multitrack Recorder which will record 4 external mics simultaneously, it also has an internal mic.
One more type of recording system is M-Audio
Fast Track Ultra USB Audio Interface which records to a laptop through a USB connection (check computer specs.)
The issue that may occur with the first two units is whether or not they will export seperate tracks in a file format that can be used by your mixing software or you could mix onboard and export as a stereo file. The m-audio inteface will come bundled with a mixing software and that will record 4 seperate tracks.

jg49 Tue, 03/10/2009 - 11:07

I looked up the ZoomH4n and it will transfer files in .wav format which is pretty universal for editing software but the recorder also comes bundled with Cubase LE which is an awesome software platform and should easily fit your needs if you want to learn how to use it, it is rather complex because it does so many different things including video editing which might be a plus!

anonymous Tue, 03/10/2009 - 11:34

Yea, wav files would be simple enough to work with. I'm comfortable working on computer (I'm a visual effects artist, working with complex software every day) Cubase should be fine I think.

I'm waiting to hear back from Samson about the multi-track saving on the H4N, if it can save each external Mic as a seperate file, then I will get the H4N. If not, then I'll continue looking to see what other recorders can possibly do this.

I will have to play around with the gain and any limiter settings that the recorder has to make sure that the loud engine sounds do not clip. I imagine that would probably take a few test runs to get it nailed down? Or does the limiter have some sort of 'auto' detect if it detects something louder than it can handle, it'll back off on the gain with out much distortion? I'm not sure how all of that works specifically. I imagine that I'll not have much trouble once I get more familier with it, but do you have any tips for recording loud sounds like an engine? I imagine that I would set the gain a decent amount lower than i think I need to, since I won't be entirely worried about loosing subtle softer sounds, at least for the intake and exhaust mounted mics. The interior cabin mic I would probably want a bit more sensitive (to hear the shifter and clutch linkage sounds)

Now that I think I have my recorder picked out, I'll just pick up some cheap lavalier mics. I suppose that since one of the mics will be mounted on the exterior of the car (the rear bumper) it will be subject to wind. Any suggestions for a windsock? I've seen some that look like foam, and some that look like a furry ball. What are the characteristics that I would be looking for in a windsock that would be put onto a small lavalier mic? Obviously I wouldn't want it to fly off, so I could probably just glue it to the mic. But what about the different types of windsocks, anything in particular that would work well for what I'm trying to do?

jg49 Tue, 03/10/2009 - 11:54

Limiters are not standardized but these small recorders that advertise limiters usually means that it works automatically to reduce clipping and distortion but really you want settings that are low enough to avoid the limiter as it can sometimes create volume issues (that can be adjusted later just more work) as far as up and down.
Sorry my last post was not clear in that the recorder will download seperate wav files for each track.
It is best to try to get gain settings correct but digital recorders can record well leaving a good amount of headroom for louder signals unlike tape recorders which the signal needs to be as high as possible w/o dist.
A friend recently brought his h2 to a recording session we were doing and I fooled around with it. I did some quick recordings and listened to them with a good set of headphones and thought it made good recordings. This was hardly a thorough test of the unit but I think it is a good unit.

anonymous Tue, 03/10/2009 - 12:29

jg49 wrote: Sorry my last post was not clear in that the recorder will download seperate wav files for each track.

That sounds good, I'll go ahead and pick up the H4n :-) And thanks for the tip on the gain :-)

Any suggestions for a windsock? or will pretty much anything work well?

Hm... this may be a silly question, but where's the best place to order one of these? I usually order my photography stuff from B&H, they also have video/audio stuff, but they don't have the H4N (saying it's not available yet). Is this recorder available? Or is it still waiting to be released?

anonymous Tue, 03/10/2009 - 18:58

Thanks, I've got it ordered from

I've got a question, I've been looking for lavalier mics, most of them say condenser, haven't found any that say Dynamic. I guess I should just grab a few different brands that are condenser and try them out next to the exhaust to see how they handle the loud exhaust?

Once it arrives and I do a few tests, I'll post up some of the results if yall don't mind :-)

anonymous Tue, 03/10/2009 - 21:03

Ok, I've started looking for lavalier mics, since I'm gonna start with cheap ones to see what they do, would something like this work? (with an adapter to fit XLR jacks)

it's $5 with free shipping, and they have a quantity of 6 of them available. for $30 I could have 6 mics to experiment with. Would this condenser mic work with a very low gain setting on the recorder? Or do I really need Dynamic mic?

While rummaging around in my box of old forgotten audio/video equipment, I found an Audio-Technica PRO 2AX, which on the side says it's a Cardioid Dynamic. This would certainly do for the engine bay or the exhaust mic, ay? I'm glad I found this! However, I'd still like to find a lavalier Mic as well. For the exhaust out the back of the car, would it really matter if the mic is cardioid or Omni? For the engine bay mic, I doubt it would really make much difference at all since it'll all be bouncing around in there.

anonymous Mon, 03/16/2009 - 12:11

Here is one of the short tests from this weekend. The loud part is 25 seconds in, incase any of yall turn up the volume to much at the beginning. :)

Is .mp3 (256kbps 44,100hz) a good setting to save out for sharing with yall over the web?

exhaust mic:
engine mic:

I should have taken some photos, since that would probably be more useful when asking for critiques to make it better! I will take a few photos of the setup next time. The setup for this evening was as follows:

Rear bumper: my old Audio-Technica PRO 2AX Cardioid taped to the rear bumper (a block of soft foam inbetween the mic and the bumper to reduce hard vibrations), the Mic had a regular foam filter on it, doesn't appear to have picked up any wind pops (though I only got up to about 70mph at the top of 2nd gear). The Mic was facing down towards the ground, inbetween the two tail pipes about 1 foot higher than the pipes. I'm guessing that the EV-635 (on it's way right now) may do a little better like this, since it's an omni and not a cardioid? The popping and crackling is actually the exhaust, it pops and crackles every time the throttle is closed up and the engine starts to engine brake.

Engine bay: $15 radioshack lapel mic (condenser I assume?) wrapped in foam and taped to the radiator overflow reservoir on the driver side of the engine bay (the air intake is on that side). I don't think it will matter to much where I put this mic, since the supercharger is fairly piercing in the upper RPMs.

Recorder: Zoom H4n with levels set at 10 (of a possible 1-100), no auto levels, no compress/limiter, and no other additional settings that I am aware of. output was WAV44.1khz/24bit. I see that there is also a WAV48kHz/24bit, would that sound any better than WAV44? or is that not going to make much of a difference?

I'm wondering if it would be worth it to try and rig up a beam that sticks out about 2 feet from underneith the car so that the mic can be mounted facing the rear of the car? I imagine the farther away from the car the mic gets, the more wind will be hitting it? The EV-635 Omni will be arriving this week, I will to a side-by-side comparison of the two mics and see which one sounds better.

So far (at least with my car) it doesn't appear that anything has clipped in the audio. That much I'm happy about! I ran 2nd gear a bit higher than normal so that the rev limiter would kick in and get a loud back fire. It appears that the backfire didn't cause any strange sound through the mic, so I'm guessing I'm ok. On the Zoom I had the input level of both mics (gain?) set to 10 out of a possible 100. The part of the audio where the RPMs are low, is very quiet. I guess I would need to animate the gain in post, or do some sort of auto levels/limiting when recording to have the difference between low RPM and high RPM not be as big?

As for the actual quality of the audio, I'm left wishing for more. I haven't done any equalizer or any other adjustments to the audio, so I'm guessing that with proper EQ and some hiss removal it will get better.

How good these captures sound for raw elements? Any suggestions for improvement? The exhaust mic sounds muffled to me, which may be a result of it being pointed straight towards the ground instead of straight at one of the pipes? The engine mic sounds very 'hissy', this may be a result of the mic being a cheap lapel mic? or maybe this is just what the inside of the engine bay is going to sound like since there is alot going on under there?

I picked up (at target) a roll of bed foam (the type with fingers, hah!) to cut up, figuring that I could at least use it to put inbetween the Mic and the bumper (which seemed to work!) and possibly use to make my own wind socks of varying shapes and thicknesses, especially for the small lapel mic. That to appears to have worked, but I'm not quite sure what this foam does to the sound? How much does foam affect normal sounds?

Thanks for any critiques and suggestions! I know this is alot of questions all lumped up into one reply (sorry!), I appreciate any feedback given :-) This first test was alot of fun, but it sounds like there is plenty of room for improvement :redface:

On a side note, I'm guessing that most folks here are doing studio recording, can any one suggest a web forum that is dedicated to field recording, or something more along the lines that I am doing? I'd like to get as much critique and assistance as I can :)


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