Getting decent video audio on your Seven

[xcarguy]

Gale,

 

If you want it to, the tranny will shift very fast, especially well above 6000rpm (6500 for me). Day and night diffenence in this tranny and a stock TKO . . . very pleased and money well spent.

 

Thanks

Checked it out.

Cool.... its a dog box but has helical gears instead of straight cut . The syncros have been removed. Thats why the clunk when you shift. It should shift very fast.

Gale

[xcarguy]

FINALLY . . . :svengo:. . . I got some on-track video with acceptable engine sound (acceptable for me)! :hurray: I'll post the video in the Seven Videos section. :seeya:

[Croc]

Rob Nokes Guide to Recording Cars

http://designingsound.org/2010/08/rob-nokes-special-guide-to-recording-cars/

[Croc]

I have continued my personal interest in this topic by following up with WindCutter who specialize in sound recording solutions including wind shielding for microphones. Below is an extract from an email exchange I have been having with Michael Stamp of WindCutter. He very kindly consented to me posting extracts of his email on this forum as I believe it is very helpful for us to hear from a professional. indented text in blue is from Michael's email:

 

Email

 

I've been giving your problem some thought and have a few ideas that can be tried to reduce the wind noise. I noticed you are trying to capture the car's unique engine sound. In the sound recording industry the proper term for any sound you want to record, is "sound". Any sound that you do not want to pick up in your recording is called "noise", as in wind noise. For example, if you wanted to capture a recording of a bird song and there was a car engine being picked up in the recording, the car engine would be referred to as noise, and the bird's song would be referred to as sound. Likewise, if you were intending to record only the sound of a car engine and you picked up the sound of an unwanted bird, the bird sound would be the "noise".

 

Recording moving car sounds is one of the most difficult recording situations, especially at high speeds. There are several problems that must be dealt with.

 

1. Equipment.

 

I suggest you use an audio recorder (like your Tascam or Zoom) and separate wired microphone/s.   The recorder can be inside the vehicle and a wire run to the microphone/s. The mic wires should be taped down using gaffer's tape

 

Gaffer's tape is designed for this purpose. It's strong, re-positionable, sticks very well and won't harm your car's finish. A good lavalier mic should work in most cases where the sound you are after isn't to far from the mic. You will need to shock-mount your microphone so it doesn't pick up unwanted vibration noise.A shock mount can be made using foam or rubber as an insulator between the microphone and the mounting surface. If you would like, I can design and build a shock mount enclosure system for your particular microphone/s. Some Zip Ties would be handy for securing your shock-mounted microphone to your desired mounting locations. And of course you'll need a StormChaser WindCutter designed to work with your particular set-up.

 

2. Microphone Placement.

 

This takes some experimentation and trial and error. You may find it helpful to have another person drive the car while you test your record levels on your recorder while listening to the live sound through headphones. You'll be watching your meters and listening to make sure your audio levels don't peak (too loud). Also, you should be listening for any rattles or vibrations in your mics mounting. You'll also be listening to determine if you are getting the sound you want without noise that you don't want. You may have to try moving the mic or adjusting it's angle to avoid unwanted noise and try again. When mounting the microphone, you want to avoid surfaces that will get very hot. You also want to try to keep the mic out of pick-up range of radiator fans and any other engine parts that create sounds that you don't want in your recordings. I like your idea of placing a microphone on the rear fender aimed at the exhaust pipe. Some long strips of gaffer's tape should be able to secure a mic in that location. The mic would need to be both shock-mounted and shielded from the wind stream. I have some ideas about how to get it shielded from the wind and shock-mounted. My idea is to place the mic inside a plastic tube like a PVC pipe. The inside of the tube would need to have some sound dampening foam like what microphone foam windscreens are made of and it would also need a shock mount system built into it. The interior foam material to prevent any reverberation caused by sound waves bouncing off the interior of the tube. The outside of the tube should be wrapped in something like Neoprene rubber or similar material. This outer material would serve as a first level shock-mount and protect the car's finish from scratches. In addition to recording the exhaust sound (called the exhaust "note"), you'll probably want to place a separate  mic to record the engine sound. This can be done from under the bonnet. This type of placement can be tested with the car's engine running while the car is still and then tested while at speed to check for wind noise. Once again a tube apparatus might work well in the engine compartment as well.

 

3. Technique.

 

A lot of trial and error to discover what works best. Here is a link to an article by an expert Hollywood sound man who has a lot of experience in recording car sounds. I think you'll find this article helpful in learning some of the techniques the pros have developed.

Rob Nokes Guide to Recording Cars

 

Best regards,

 

Michael

Design & Fabrication

TheWindCutter.com

http://www.thewindcutter.com/shop/

 

 

 

 

 

 

 

I will note that I use the WindCutter microphone "dead cat" wind shielders and they have been the most durable out of all brands I have used so far, although I suspect they would melt if taped to the exhaust...

[timax]

Very similar to what i came up with which is to tape down a mic to a foam block on the passenger floor. Then tape a bowl over top of the mic. Steel bowl gives a different sound to plastic so experimentation is needed. I was using a Zoom H4N with a Sure Mic and also the Zoom alone. It works well but the complexity is silly for anything less than pro use. Gave a good mix of exhaust and engine but a little too much gearbox.

What i use now is like most people , a lav wrapped in foam stuck just behind my windscreen. Gets a good reflection of the exhaust with a little bit of engine and some wind. But i like that as its closer to what im hearing inside my helmet.

One thing i would like to try is a helmet mic to pick up even closer to what i hear plus some commentary or more likely laughter and expletives. Its usually one or the other isnt it?

[Croc]

Strangely, the foam wrapped mic behind the scuttle just does not work in my car. I think it is because I have such a different dash shape in the CSR. hence I have always been trying to go to the next level. I tried the bowl trick - sounded too hollow. Given I have broken 2 digital audio recorders in the first time I used them I figure I will stick to using the GoPro to record sound.

 

I will be trying next season a splitter for intake and exhaust with dual mics. Should be fun.

[Croc]

This is not really related to getting good audio on our videos of track day/race fun but I thought it was a good spot to lay out this next effort.

 

One thing that has bugged me for a long time is rolling shutter. The CMOS chips used by virtually all the action camera companies is set up to process video line by line (i.e. it rolls through the image over and over) and therefore accentuates the likelihood of getting rolling shutter effect no matter how well you fix a camera to a roll bar (and I use solid metal Manfrotto clamps with very solid Manfrotto ball heads).

 

To get around it I use a higher frame per second setting - 60fps instead of say 30fps. Some cameras are more susceptible to it than others. The Sony FDR-X3000 is a brilliant piece of kit but it gets more vibration affected than say the GoPro Hero 4 black that I also use.

 

The best camera was the Braun Six Zero but my original one died with a rock to its lens. It was different to the other action cameras as it used a CCD chip which has a global shutter instead of a line by line rolling shutter. However, they are impossible to find these days as they are out of production. CCD chips are still found but in very high end professional video cameras (think Red, Black Magic, high end Sony, etc).

 

So I went in another direction - could the anti-shake ("Steady Shot") features on a Sony action camera fixed the vibration or risk of rolling shutter effect?

 

 

 

Sadly no - look at the image hunting around trying to focus on the straight ahead.

 

So when I was given the chance to try out a Feiyu FY-WG 3 way gimbal like what they use on aerial drones for video work, I jumped at it. I figured if it made videos of mountain bike riding, running, and drones smooth then think what it could do on track.

 

So I devised a side by side test run at the same time, same session, same car, same driver:

 

Side A

The Feiyu FY-WG gimbal with a Hero 4 HD Black running a 1080 resolution at 60fps, mounted using my usual Manfrotto hardware to my little maroon Caterham road sport at a very crowded drivers club event. To avoid any issues with the mic cable I just used the internal mic within the camera body - wind noisy as a result. You can watch in 1080 60fps to see the true quality.

 

 

 

 

 

Side B

The same but without the gimbal. I used my external mic here. You can watch in 1080 60fps to see the true quality.

 

 

 

Lesson - The gimbal and steady shit anti shakes do not work. You are better off with solid mounting and some bracing to stop the wind shakes. I could have done better on Side B but it still was a long way ahead of Side A

 

Second lesson - a rock from a car ahead will kill a go pro but not the gimbal as I discovered at the end of this track session. Better the camera instead of my visor I suppose!

Edited June 8, 2017 by Croc

[Croc]

Continuing in my journey of decent audio on Caterham track videos, I have reached 'nerdvana'

 

Two mic set up. Garmin VIRB action camera mounted to rollbar using manfrotto clamp. Twin mic set up using a 3.5mm cable splitter. Twin AT Pro CM 24 mics - internal battery power works better than camera providing power to mic. Both mics are covered with 'dead kitten' mic covers.

 

One mic runs forward along passenger side of cockpit and around outside of scuttle into engine bay where I tape down the mic with non-marking painters tape under the intake on the top of the passenger footwell inside engine bay. Photo link shows the line of blue tape and camera on roll bar.

 

 

 

 

Second mic runs backward and is taped down next to rear exhaust - photo illustrates. The blue painters tape shows the line of wire between camera and mic.

 

 

End result is pretty good.

 

 

 

If you have a side exit exhaust then revert to single mic setup with mic in engine bay or second mic inside boot (under boot cover) near side exhaust.

 

 

 

 

[Croc]

Now that I have reached a level I am happy with on audio recording Caterhams at high speed (took me long enough!), I am now focused on improving the video.

 

A UK track buddy lent me a new DJI Osmo Action camera to play with this week at Donington. So I tried 3 settings:

 

1) 4K 60fps with RockSteady. Rock Steady is the vibration and movement reduction that is intended to smooth out the video images. I had tried this with the early version of a Sony Action Camera earlier in this thread and somewhere a few posts above you can see the results of my experiments with a gimbal (failed). The Osmo is essentially identical to the current top range GoPro steadyshot feature.

 

2) 4K 60fps with no RockSteady

 

3) 4K 30fps 4:3 ratio and no RockSteady

 

 

Ignore the laps. It was close to freezing, alternating snow, hail, and drizzle plus a Locost dropped oil around a third of the circuit closely followed by a Datsun 350Z dropping coolant all over the circuit. Donington is notoriously dangerous in slightly wet conditions thanks to the East Midlands airport next door. It actually gets grippier as it gets much wetter as the avgas stuff gets washed off.

 

 

 

Test 1 - 4K 60fps and no RockSteady

 

 

 

 

Bounces around with vibration. Donington is a bumpy circuit with quite a few patches. Not too bad though.

 

 

Test 2 - 4K 60fps with RockSteady

 

 

 

 

You can see the RockSteady feature in 2 ways. It crops the video image - about 10-15% of the image has gone compared with test 1 image above. Secondly, you can see it slightly hunt around as it seeks to compensate for car movements. Much much improved over the old Sony. Not convinced it is better than Test 1? I am curious to see what others think from the comparison.

 

 

Test 3 4K 30fps 4:3 ratio and no RockSteady

 

 

 

 

No real difference to Test 1 in image quality to be honest. The change in screen ratio from 16:9 (Test 1 and 2) to 4:3 was intended to see if it produced a better field of view. While you see more of the driver and his actions, you lose the wide view. Not convinced its better. Feels slower because of the change in perspective - a wider angle feels faster. Again I will be interested to see what others think from the comparison.

[panamericano]

Looks like 1 & 2 are both good. Initially I liked 2 better. Then, with small images I played both at the same time. Great feature of the web site. The water on 1 may be part of the reason 2 looks so much sharper, but 2 does really look better focused for near field, cockpit, bonnet, etc. The color saturation looks a lot better in #1. Have you tried a helmet cam?

[xcarguy]

Great vide, Mike. I’m leaning toward vid #1.