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  • Best way to capture onboard car audio (for a month…)

    Posted by Joao Grade on November 5, 2010 at 2:17 pm

    Dear users,

    I haven’t decided which way to go for audio capturing regarding my next project.

    Thing is, we’re shooting a documentary and tv series, by accompanying a rally team for over a month. On the competing vehicle, I wish to capture cockpit audio, mainly dialogue between pilot and co-pilot. Bear in mind this is an amateur rally (the world’s biggest), relatively laid back one, not that much speed involved, etc. So the dialogue will spawn several subjects, not entirely related to navigation. This is a very important feature for the outputs, what is said inside the car between the two crew members.

    Image will come from two onboard cameras (main car) and an HD from a second car following the first.

    So in order to capture the audio from the main car’s cockpit, what is my best choice?

    Bear in mind it is a convertible 4×4.

    I thought of using wireless lavaliers, one for each crew member, connected to two receptors hooked to a portable recorder on the dashboard. But I think the whole clothe scrubbing, and the wind, among other things may affect the result.

    So I am thinking of keeping the portable recorder, and using one or two mics, facing upward to the middle or to both occupants (one mic for each). The mics would be low, more or less at gear shift lever. If they are properly fixed, there shouldn’t be a problem. Is this a sound option? Will it yield the best results? If so, which type of mic or mics should I be aiming at? Cardioid? Hypercardiod?

    I will be listening to the conversations but cannot monitor them, so the portable recorder audio level will have to be setup before hand, and if needed the co-pilot may check it using headphones that will be hooked up to the recorder. I know, it’s far from ideal, but I can’t think of a way to monitor the audio myself constantly, since I’ll be in a second car following the racing car. When I say racing car, I mean a 37 year old Land Rover (80 kmph max).

    Step 2, if this mic setup is ok, and if the portable recorder is a good option, which should I go for?

    My limit for the recorder is around 600€, and after reading a few reviews and opinion, I’m narrowing it down to these models (not in order of preference):

    – Tascam DR-100
    – Marantz PMD661
    – Zoom H4n
    – Fostex FR-2LE

    Or, if a good second-hand deal can be made through ebay:
    – Tascam HD-P2
    – Marantz PMD671
    – Edirol R-44

    There are a couple of issues to be taken into consideration:

    According to what I’ve read in a few places, there is or there could be an issue regarding the phantom power usage, some people saying if one hooks up xlr phantom powered mics on a portable recorder such as the Tascam DR100 or the Marantz PMD661, a generous hiss comes through, rendering dialog capture almost useless, or at least very far from broadcast standards. They say it’s due to the high noise environment the recorders are aimed at.

    Therefore this could be a problem, or if I use a Rolls PB223, for example, no hiss will be generated? “The PB223 can phantom power 2 microphones with 48VDC. Since the unit uses a 100KHz switching power supply there is no audio noise generated”. Or should I just go for AA powered mics?

    Power and memory are not an issue, that much is covered (car battery 12v adaptor and laptop).

    So yeah, that’s about it, I just want to reach a decision because I need to buy the equipment, set it up and test it.

    What is your general opinion on this? Should I go with the shotgun mics and portable recorder? Or do you foresee a totally different and far better approach?

    Sorry for the extended topic, I wanted to make thinks as clearer as possible.

    Thank you very much indeed,
    JP Grade

    Peter Groom replied 15 years, 5 months ago 5 Members · 19 Replies
  • 19 Replies
  • Bob Kessler

    November 5, 2010 at 5:36 pm

    Of your recorder choices I would go with the FR-2LE, PMD-661 or used HD-P2. If you go with the FR-2LE or PMD-661 check out Oade Brothers – they sell modded versions that greatly improve the sound for very little over the normal selling price.

    As far as sound capture of the driver and navigator can they wear headset mics? Perhaps something like this?

    https://www.bhphotovideo.com/c/product/247421-REG/Shure_WH30XLR_WH30_Headworn_Condenser.html

    They could be hardwired directly into the recorder and would greatly mitigate the other sounds in the vehicle as the crew will be speaking directly into the mics.

  • Joao Grade

    November 5, 2010 at 5:46 pm

    Hi Bob, thanks for the input.

    I haven’t thought of headsets, but it sure looks like a very reliable option. Must check with the crew first, see whether won’t bug them to have the gadget on their heads the whole time.

    Thanks.

  • Jean-christophe Boulay

    November 5, 2010 at 6:29 pm

    In the rally car, won’t they have radio headsets already? They usually do, so they can hear each other over the engine and wind, though I’m not sure with the type of rally you describe. If so, you could split that out and send one feed of each member to the recorder. The manner of splitting would depend on what kind of connections the radio gear uses.

    If they don’t have headsets already, getting them some as Bob suggested seems the best option to me. My second choice would be lav mics mounted on their collar. Seeing this from the mixer’s perspective, a farther mic’ing would complicate separation of voice and ambiance and effects. The gear shift stick is just too far and off-axis, IMO. It’s better to have some slight clothes rustling to remove than a blaring engine. I’ve once received audio recorded by mounting small, very directional mics to the inside of the windshield and that sounded pretty good, too.

    Being a creature who inhabits the cozy world of the studio, I couldn’t really comment on the recorder of choice, though.

    IHTH,

    JC Boulay
    Technical Director
    Audio Z
    Montreal, Canada
    http://www.audioz.com

  • Joao Grade

    November 5, 2010 at 7:23 pm

    I see what you mean, but they are not using headsets no.

    Ok, maybe the near the gear shift option won’t be adequate, if I am able to fix a couple of mics on the dashboard under the windshield, which would you recommend?

    But I’m inclined with the headsets previously recommended, it seems a good choice. I have to check with crew first, I’m afraid of movement constrains and feeling weird to have an headset all the time on, don’t know…

    Thanks Jean.

    edit:
    Although I think using the headset will make sound capture more exposed to wind. It’s a convertible car, have a look http://www.afroteam.org.

    thanks.

  • Ty Ford

    November 6, 2010 at 12:11 am

    Hello Joao and welcome to the Cow Audio Forum.

    Try Countryman E6 mics with pop filters. They take up negligible space in the helmet. Or find a place in the helmet to glue a lav.

    Pray to MacGyver. 🙂

    Regards,

    Ty Ford

    Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
    Watch Ty play guitar

  • Joao Grade

    November 6, 2010 at 10:08 am

    Hey Ford, appreciate the input, but the guys aren’t using helmets.

    Will face them with the headset solution, but I’d like to keep them movement free, no wires, nothing, just let them be focused on their thing, not having a gadget on their head.

  • Ty Ford

    November 6, 2010 at 11:57 am

    Joao,

    Let us know how it works out, but an open vehicle and its wind noise and engine noise seems like a recipe that demands close micing. Mounting mics on the vehicle, you’ll also have to consider a suspension mount of some sort or how to pad the mic so it picks up as little vehicle vibration as possible.

    If you only have two front seat folks try to figure out how to rig a small directional mic in each visor.

    Regards,

    Ty Ford

    Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide
    Watch Ty play guitar

  • Peter Groom

    November 8, 2010 at 1:18 pm

    I did a very similar thing to this about 6 months ago. It was a commercial, but involved 2 cars (1 a cab) driving round and 4 models im the cars looking pretty and capturing their comments.
    I found that the cab was a real problem as the wind noise swirling round was mega. I recorded the 2 wired Sony ecm 77 s to a zoom H$N. the mics mounted at the closest possible point to their mouths, but still lavs want to be close and with a lot of noise about there were issues. The zoom can be powered from the cars 12v via a cable we bought.
    If you get say a 32 gig sdhc card and run stereo recordings in mp3 (256kbps) you can run all day and night no problem.

    Personlally Ive never seen a rally where they dont use helmets but hey!
    My best advice is, as i did, test run and test and test to find the best position you can with the roof down. But its not easy or particularly good.
    When we did a motorbike section, mounting the ecm77 inside the helmet was spot on with a rycote fluffy over it.

    Peter

    Peter

  • Joao Grade

    November 8, 2010 at 1:34 pm

    It’s that type of rally Peter, wearing a helmet is optional. But I had thought of that, and had a chat with the drivers, they won’t mind wearing a helmet or a headset, as suggested by a previous commentator. I’ll have a look at them microphones you mention, but unfortunately I have to quickly decide on what kit to buy, and then run the tests. Do I must think of the best solution possible so I may buy the equipment, and if it’s not the adequate setup, I would have wasted money and be still be without a solution.

    For visual purposes, which is one thing I’m overall concerned, I’d like the guys not to wear a helmet nor a headset nor a lavalier, I’d much rather have a concealed capture solution, maybe those short shotgun protected near the wind screen, like one user also suggested.

    I really don’t know, but I have to decide pretty soon…

    If I had enough to invest on two setups, short shotguns + wired or wireless lavs, I’d go for both and know I’d have a solution between the two.

    If someone could suggest a nice quality wired lavs, besides expensive brands, I’d go for both options and invest in a pair of wired lavs. I’d also consider wireless lavs if only I would know which ones to buy, preventing me from spending over £600 on Sennheiser g3…

    So yeah, I’ll go forward with a portable recorder, most inclined to the PMD661. Mic wise, that’s the tricky part…

  • Bob Kessler

    November 8, 2010 at 4:51 pm

    Now comes compromise time. As you get further from the two folks in the car the more noise will be introduced to the recording and the less voice intelligibility there will be.

    The Inverse Square Law

    In simple terms, this means that a sound twice as far away is only one-fourth as loud. A sound four times as far away is only one-sixteenth as loud. So a human voice that records with adequate volume three feet away is just one-sixteenth as effective at twelve feet.

    Once you get into wireless you’ll have more likelihood of drop-outs, RF interference and the batteries have a limited useful life (2 – 4 hrs continuous) and you have two rec/trans systems to worry about. That’s why I recommended hard-wired.

    Just one more thought; if you cannot understand what they are saying – and you mentioned that the conversational by-play is the focus of the project – then everything else becomes meaningless.

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