Greetings,

I posted part of this request for information in the tapeless recording subforum (http://www.dvinfo.net/conf/showthread.php?t=53250), but figured the sound portion is better posted here.

I would like to discuss my current project and thinking with the hope that your expert advice/criticism/praise/feedback/suggestions will help me make the best choices to achieve my goals. Please don't hold back!


The Environment
The racecar is an ANDRA spec Sport Compact Modified class car racing in the Australian drag racing series.

A drag racing pass involves lining up to race (0-30 minutes, not of interest), performing a burnout and staging (1-3 minutes, of interest), the launch and race (1 minute, vitally interesting) and the braking zone and returning to the pits (1-5 minutes, of some interest).

Current setup
Previously we trialled the concept with a bullet camera (Sony EX-VIEW HAD) hooked up to a Sony DCR PC9E (PAL) miniDV camera with two mics (one in cabin and one under bonnet).

We also had a grandstand view of the drag strip shot on a Sony DSR-PDX10P (PAL) with miniDV using the Sony XLR mic. We used a Manfrotto fluid head tripod.

Post production was using a JVC MiniDV firewire deck hooked up to the PowerMac G4 and iMovie.

The grandstand footage was pleasing and the XLR mic on the PDX10 did a reasonable job. The bullet cam footage was good when the camera was located out of the direct glare of the floodlights along the drag strip. The sound using the unbalanced mics was not good. Particularly the underhood mic produced lousy sound.


Project Design
Grandstand Camera: PDX10P
For the grandstand PDX10P setup my only thoughts for a better outcome is to get improved sound. The camera is located say 100' perpendicular to the drag strip and elevated much higher. There are also loudspeakers carrying commentator's voice along the strip.

Any suggestions for a good XLR mic to capture the race mounted on the PDX10P? Any comments on running another XLR mic to capture the commentator's voice and running this to the PDX10P as well?


Incar Sound
We've ordered the Studio 1 XLR adapter XLR-BP 3 Pro (http://www.studio1productions.com/xlr-bp_3_pro.htm) to enable me to hook up three XLR mics to the miniDV 1/8" mini stereo jack.

We have no suitable XLR mics at this point and would love suggestions. My thinking is to capture these three audio sources:

CABIN: Located in the racecar cabin to capture the sound from the driver's point of view.

ENGINE: Located under the hood to capture the engine, turbo, blow off valve sounds. How do I ensure that this very harsh environment can give me clear and balanced sound?

BUMPER: Located on or near the rear bumper to capture the exhaust sound. Is it possible to capture the sound of the parachute deploying? This location is external to the car, although not in the direct airflow (rear bumper) and so I am concerned about how to capture clear sound.

I would appreciate suggestions for mics for these three locations, bearing in mind the sounds will be motorsport type sounds.


Digital Recording Devices
Originally we planned to simply add additional Sony miniDV cameras as the recording devices. However discovery of tapeless digital recording devices has opened up other options.


Physical Device Location
The bullet cameras have mounts on various places within the rollcage structure. The signal and power cables will run along the rollcage in conduit to the media box.

I am not sure how to mount the mics at this point. Suggestions? The mics will feed back to the media box.

The media box will be located either in the passenger seat area or in the rear compartment. It will be constructed of carbon fibre or alloy and will be mounted to the floorpan with rubber insulation. The interior will be mounted with foam to provide some ruggedisation against shock.

The DVR units and the XLR adapter will be mounted inside and perhaps the cabin mic too. Provisions for power will be here too. Finally all the cables/leads will run to this box to control the DVR units.


Questions
What do you think of the project design as outlined? Any suggestions for improvement?

Am I on the right track here or is a major re-think in order?

What mics do you recommend for the various locations (above)?

Anything else to help me out?

hi kenny,

i mic nhra tf drag racing over here (usa), much louder than sport compact, but the concepts are the same.

i use several mics along the race track, mixed into one feed that covers the whole racetrack. i have mics at the start area for staging/burnouts, and one that looks downtrack for fill to the finish line. mics at the finish line (i like the dopler change to identify the finish point-even if you can't id it visually). the best chute sound will be just off the wall near where they pop the chute (200feet or so past the stripe). i usually put the mic past this point-pointed back towards the start line-hopefully they are off the gas by the time the chute deploys for maximum poppage. i then have several mics between finish and the turn off point, mixed one by one as they go by to give the illusion of continuous coverage of sound. incar is tricky, i'd forget the engine compartment due to heat alone. anywhere outside of the car runs into serious wind noise issues, although on the back bumper area might be ok. inside of the driver's compartment you may find this to provide all of the sounds you mentioned, i've been able to hear the car in the other lane from this perspective. i've been somewhat unhappy with my incar endevors, but the people that own the gear are unwilling to put higher quality mics in the car, affraid of damage/loss due to potential car crash. i'd take a chance with my own gear in sport compact, trying something omni to start with. make sure its all fastened down securely, and has the approval of the driver/owner.

for your purposes, i would suggest a mic with high spl rating (higher than 130 db/spl) for your grandstand camera. i like the sennheiser mkh-416p myself. i also use the blue "eight ball" near the christmas tree. (i have blown the elements on many mics due to too much noise level-but then thats top fuel for you). the pa speakers are always a problem in the grandstands, one of the reasons i have a lot of mics inside the pa throw. it would be nice to shoot on a testing day with no crowd or pa. sometimes an inline attenuator is in order, as the mic with loud race noise may exceed the input ability of your camera.

let us know how it goes.

Hi Greg,

Thanks a lot for your reply. A couple of additional questions:


..
incar is tricky, i'd forget the engine compartment due to heat alone. anywhere outside of the car runs into serious wind noise issues, although on the back bumper area might be ok.

What model would you recommend I give a try for the rear bumper?

..
inside of the driver's compartment you may find this to provide all of the sounds you mentioned, i've been able to hear the car in the other lane from this perspective. i've been somewhat unhappy with my incar endevors, but the people that own the gear are unwilling to put higher quality mics in the car, affraid of damage/loss due to potential car crash. i'd take a chance with my own gear in sport compact, trying something omni to start with. make sure its all fastened down securely, and has the approval of the driver/owner.
..

Again, what model/brand of omni mic would you recommend I try for the in cabin?

for the bumper i might try to mount my mkh-416 in zepplin, keep it close to the back and hopefully out of the wind stream. but if you are thinking drag chute pop it will prob get lost due to proximity of the tailpipe. inside i'd go with my DPA 4006 omni. that's where i would start anyway. i usually end up trying LOTS of things until i get the sound i'm looking for, or at least something that i like the sound of.

for the bumper i might try to mount my mkh-416 in zepplin, keep it close to the back and hopefully out of the wind stream. but if you are thinking drag chute pop it will prob get lost due to proximity of the tailpipe. inside i'd go with my DPA 4006 omni. that's where i would start anyway. i usually end up trying LOTS of things until i get the sound i'm looking for, or at least something that i like the sound of.
Thank you Greg, that gives me a starting point.