Car to car IFB Fidelity Equipment / solutions

[ChefMozay]

I’m working a show where they do car scenes (go pros, drop audio bag in car, etc.) I’m looking for a solution or equipment to do high fidelity IFB sending from the go pro car to producer car. Obviously its a spotty situation, the cars are moving, so I’m sure that its just the situation but I was wondering if anyone knows of a fix or solve. Thanks!

 

and of course I’m sure im not giving as much info as needed so feel free to ask for more. 

[Axel Mishael]

Lectrosonics IFB, I don't know if you can get a handle on any of the 250mw transmitter, other than that, an old g3 sennheiser can do it.

[Jeff Wexler]

I will weigh in on this but I'm not able to recommend brands or specific gear other than what I used to use. I will say, personally, having done these sorts of scenes many, many times, I always had really good results using my Zaxcom gear. Whenever we did car to car stuff, I would go wireless from the picture car to a follow van where I would be with all my equipment along with usually the Director, Script, etc. Never felt the need to do the "bag drop" routine since I had rock solid backup recording in the transmitters. For IFB, usually it was just my usual Comteks for other people in the follow van. I do remember once having to have 2 follow vans, and in these cases I had to have IFB to 2 vans (which I did usually with additional wireless). One thing I would recommend highly when doing any of these sorts of scene is to work out a way to have all receiving and transmitting antennas positioned outside the vehicles  ---  this makes a bog difference. For the talent wireless in the picture car I would remote the transmitting antennas for wireless plants and on the follow van, remote the shark fins outside the follow van.

[Trey LaCroix]

High fidelity IFBs are few and far between in my experience. An IEM system can sound good, but you’re often limited by stage transmitter options. Comteks are far from HiFi and I don’t think the Lectro IFBs sound that much better. The zaxcom IFBs sound really good to my ear.

I work on a show where we have to do car to car almost every day. We also constantly stop and get out of the car to shoot a quick scene so bag drops aren’t really practical. My setup is:

 

Talent car- 2 DLA 4080s or 4097s (depends on the situation) running to a small bag with a 2 channel preamp going into a Zaxcom Camera Link in stereo mode set to 100mw. I run the antenna out the window with a small clip with an sma mount.

 

Follow Car - 2 betso bow ties or fins (again, depends on the situation mounted to the outside of the car. With coax running to my Nova with me in the back seat. I can pick up the Camera Link and talent wires reliably. I hand the producer in the car an ERX and he hears it clear as a bell. IMO the ERX is fairly limited in a lot of situations but works great in a car with no other 2.4 devices around.

 

And yes, the Zaxcom transmitters can record but I don’t find myself needing them that often with this setup. Getting away from the bag drop has been a game changer.

[PMC]

I have worked on House Hunters. Sometimes as the DP. Sometimes as the sound mixer. The situation is exactly as you described it in your original post.

 

I have had success connecting the output of my SD664 to the audio input of my Android phone. Call a phone or conference several phones in the chase car and bingo. Bob's your uncle.

[Mungo]

Not much more to say, the previous posts contain rich information.

 

One last idea: FM transmitter positioned well outside talent car and tuning in the car audio of the follow car. So you don't have to care about reception antennas and loudspeakers because they're already installed:-)

 

In Europe we are quite limited in TX power (50mW for wireless mikes und much less for FM transmitters), so over here, I would prefer some audio-over-IP solution as mentioned by PMC. 

Nevertheless I have made good experiences with Sony DWX w/ sharkfins on the roof of the follow car in the countryside. But in urban areas, where you sometimes lose sight (e.g. when having to stop at red lights), range might be too short.

[BAB414]

I love the phone idea.

 

I always drop the bag in the picture car, just to be safe. I only use Lectrosonics. One trick I've learned is to put a receiver on the camera (either the mix from the bag, or if you're not dropping the bag, tune it to your plant mic, etc). The audio will be embedded in the SDI signal and piggyback over with the video into the follow van. Just make sure the tracks/inputs in the camera are enabled. If they lose picture, they lose sound too, and they're not going to roll without picture. Plug a speaker into their monitor's audio out (sometimes they have internal speakers depending on the monitor).

 

One downside to having a speaker is that you risk feedback when the director walkies over to the talent so speaker volume and placement (and walkie volume and placement in the picture car) are super important. If you wanted you could try plugging a comtek/ifb transmitter into the monitor output to avoid this. But the point is, piggybacking on the sdi video signal guarantees that if the video is there, the sound is there.

 

One exception to this I've found was with an ultimate arm rig. Somewhere in their signal flow, the ultimate arm car was stripping the audio off the SDI and so it was not making it to their teradek transmitter.

[karlw]

The highest fidelity IFB I can think of is to use a Lectrosonics mono digital transmitter (DBu, DBSM, etc.) set to 50 mW and then an M2Ra receiver in D2 compat mode in the producer's car. This would give you 20-20K, full dynamic range audio, in mono, if that's what you're after. To increase range, consider using an external antenna on the talent car, if feasible - a magnetic or suction-cup mount unit that is out of any camera angles and fed from the digital bodypack unit in the bag. 

[Philip Perkins]

I would ask: how much fidelity do you really need in such a high noise environment?  More than a regular Comtek can deliver?  In my experience with this kind of thing the listeners were most concerned with accuracy of line readings and performance, they assumed that the recorded audio was good just like they assumed that the recorded picture was better than what the portable monitor was showing them?  Any more, getting the audio directly to a camera attached to the rig is how I'd go, probably from a dropped bag.  I'd want to transmit to myself in a chase car if there is time to rig all that (not a given), but getting audio to a camera solves a lot of issues in one go, esp re: monitoring, video assist etc..

[edward chick]

I have used Comteks with pretty good success. Last car to car I did was for a political spot, candidate was driving a Suburban. I dropped the bag with the Comtek M 216 connected to Comtek Mini MIte  1/2 wave antenna.  I gaffed the mini mite in the back of the suburban,  reception  in follow car was great. No drop out even when not in line of sight of talent vehicle. I too, like the cell phone Idea. 

[Rick Reineke]

I usually put the bag in the car with a Comtek or other IFB to the follow vehicle . On a few shoots with an unpreditable distance, I fed the IFB and and a walkie-talkie, the walkie did not sound as good but the range was over a mile, good enough the hear what was happening when the IFB crapped out.

[JonG]

Using a Comtek basestation has been good for controlled drives. But when following in cities or on freeways I’ve also included a mini mite, which can be hidden behind one of the car seats. Clipping the receiving Comteks to the front visors, and even plugging them into the follow vehicle’s stereo has worked out really well. 

[BAB414]

17 hours ago, Rick Reineke said:

I usually put the bag in the car with a Comtek or other IFB to the follow vehicle . On a few shoots with an unpreditable distance, I fed the IFB and and a walkie-talkie, the walkie did not sound as good but the range was over a mile, good enough the hear what was happening when the IFB crapped out.

How do you keep the walkie cuing? In my experience, they "time out" after a certain period.

[Rick Reineke]

I do not recall what model , but it was a main stream radio from a NY production rental house. The PTT had a 'hold' option and I had to solder together a custom cable instead of an external headset.

[glenn]

 A Zaxcom camera link in the car transmitting with ZHD modulation will give you the best combination of no compromise audio quality and signal integrity in a mobile car to car kind of production. With recording transmitters, any number of transmitters can be replayed in sync to monitor after the fact if needed. Use a magnet mount on the transmitter car if possible. 

[Constantin]

Lots of good advice here already, and you may need to try different ones to find your best solution. I don’t have much else to add, except for three things:

 

- the cell phone idea sounded very tempting to me too, a while ago and I looked into it. So far it’s a dead end. The latency can be terrible and it can vary, so it’s annoying. The sound quality out of a phone is pretty bad, unless you can go USB in like with a MixPre, but IIRC that won’t go over the phone line. There are Bluetooth devices that will pretend to be a headset, and they have XLR inputs, but this adds even more to the latency. 
once you finally have you cell phone system up and running, you‘re bound to shoot somewhere where there’s no cell service and so you‘ll need to have another system in place and I‘d say it makes more sense to focus on that other system from the start. 
 

- getting antennas outside of the car is a big help, but instead of magnet mounts, I highly recommend suction cups. They basically cannot come off and everyone else uses them, too, so you can always borrow one. 
 

- hitching a ride on the SDI stream is a pretty good idea, but if  the director and whoever else will be in the follow car, too, they will likely expect to rely on your audio to help communicating with the picture car, even when the camera is off or out of range. 

[Matt Geldof]

I worked on a show many years back.. one of those love/taxi gigs that were so popular. We shot for weeks, audio bag in car, with two shotgun microphones mounted, along with the lavs hidden on talent. I placed a 200mw Lectro RX in the trunk, 4' away from the bag, to transmit audio to the follow vehicle plugged direct into the 15 pass stereo aux in. I needed to rescan occasionally, depending on which area of NYC we were in. The high power TX worked well. I had a 302 in the follow car, with a good pair of headphones. In addition I mounted a 100mw TX in the trunk,  that gave me a confidence monitor for the lavs and a second RX plugged into the 302 for the two shotgun microphones. This setup worked perfect for weeks of filming. I was able to isolate audio issues, from the follow vehicle, quickly pull over, solve them and be on our way. It's been awhile since I have been on a show like that, but even with today's tech / and my kit being mainly Lectro and Sound Devices, I'd likely still do something similar.