wireless timecode transmitter

[Blinddot]

Hi, im putting together a small project studio for production and postproduction sound for picture

the location recording set to buy at this moment is a tascam HD-P2 + sennheiser 416 + t_ bone EM9900 (cheap chinese) http://www.thomann.de/thoiw11_the_tb..._prodinfo.html + sennheiser suspension and windscreen

I was thinking about a lav mic with a wireless system, I´d like to know ideas about this, the wireless reciever has to be small portable and battery powered. Could you please give some suggestions?

Is there any time code wireless sytem, battery powered, to plug a emmiter to the master camera and a reciever to the tascam HD-P2.

I already have most of the studio, I work with nuendo and some times PT LE on a pc with an m-audio delta 66. My main converter is a RME ADI-2 AD/DA and my mic pre is a 2ch DAV electronics BG1, I also have a dual DI from radial engineering with jensen transfomers and a modded sm-pro audio passive volume control/monitor switching

I have a couple of yamahas msp5 as nearfields, but I´d like to add a couple of midfields something with 8" woofer or more. BM15As? Adams?

I have a cheap chinese big diafragm condenser for voice overs and some foley, but i was looking for some better one, any ideas on this?

thanks for helping

[Jim vanBergen]

Originally Posted by Blinddot

I was thinking about a lav mic with a wireless system, I´d like to know ideas about this, the wireless reciever has to be small portable and battery powered. Could you please give some suggestions?

Is there any time code wireless sytem, battery powered, to plug a emmiter to the master camera and a reciever to the tascam HD-P2.

I'd suggest you look at the Sennheiser series made for ENG applications (remote engineering, IE broadcast). These have wireless receivers that are quite small and are designed to run off DC supplies like Anton-Bauer battery packs.

Timecode systems run at line level, so any wireless system CAN do this, as long as they can input and output high level audio square waves with excellent replication. You can use an IEM (in ear monitor) system and provide line level outputs that might be fine, but I'd check manufacturer specs for maximum output to be sure.

Hope this helps!

Jim

[dolo72]

Hi
Check these guys out www.blackboxvideo.com they make exactly what you want a wireless timecode transmitter. Unfortunately it does not output a video or wordclock reference so I would hire/buy a lockit box from www.ambient.de. This is a small gadget which will jam sync to your master clock(e.g. camera) then output a timecode signal with a worclock/video reference which is vital for sync if you are going to do anything more than cut aways and short duration shots. Denecke in the US also make a lockit box but in use I have found the ambient products to be the most reliable and able to hold tight sync over long durations.

Hope that is of some help

[dkatz42]

We used a regular Lectrosonics rig (with the right flavor of adapters to get the signals in and out) to slave my Sound Devices 744t to my video guy's Sony HDcam. Worked great! You just have to play with the gain staging a little to make the signal clean and it's just fine.

I didn't try to slave wordclock to the timecode feed, but we didn't have any sync problems (that I could see) in some reasonably long shots (up to 30 minutes.) It seems odd that the sync should be problematic unless the timebase references in the machines are sloppy. If my math serves, one frame in 30 minutes is 18 parts per million, which is huge; the 744t specs out at 0.2ppm (which is a slip of about 1/100 of a frame over 30 minutes at 30 fps.) Perhaps cameras that cost six figures have good clocking too.

One thing that the 744t does *not* try to do is to tie the clock rate to the timecode frame rate, which would seem to cause unholy amounts of jitter. Basically it just timestamps the file based on the received timecode and free runs from there.

dolo72, what kind of sync problems do you see without slaving word clock to timecode?

[Sound Sorcerer]

I personally like the Denecke gear better... But since you are in Europe I would probably recommend the ZEItX products instead. The only problem with your setup is that the Tascam HD-p2 only reads TC so you may still need to get an Ambient lockit box as a master TC/clock source. By the way, before I got my Sound Devices 702t, I use to send TC to my Denecke TS-3 Slate through a Comtek Radio link from my Fostex PD4 recorder, but now I only jam the Smart Slate from the TC output of my 702t.
Si tienes alguna duda o necesitas más asesoria para armar tu kit de sonido directo échame un email...
Cheers,

[Blinddot]

Seems like my only options on the recorder are the Fostex FR2 and the SoundDevices 702T, I´d like to know your opinions about these two. The 702 is much harder to get here in Spain.

I think I´m going with sennheiser evolution wireless 500 series for the lav mic, and the Zeitx wireless TC system.

many thanks

[T.RayBullard]

Originally Posted by Blinddot

Seems like my only options on the recorder are the Fostex FR2 and the SoundDevices 702T, I´d like to know your opinions about these two. The 702 is much harder to get here in Spain.

I think I´m going with sennheiser evolution wireless 500 series for the lav mic, and the Zeitx wireless TC system.

many thanks

www.oade.com does mods on the FR-2 that sound phenomenal. He also sells the FR-2, and is a good friend. Doug Oade is his name. He sells internationally too.

[dolo72]

dkatz42
srry for the late reply had trouble posting. Basically I would see the probelms with non sychronized clocks as the usual clicks and pops and possible drift. However you enlightened me to the fact thst the sound devices has a 'free' clock and doesnt derive it clocking source from the incoming timecode so this is probably not applicable. Most of the work I have done is using the audio timecode as master clock for multicamera shoots mainly HD and Digibeta . In these cases the wordclock/video clock has to be used for synchronous clocking for the embedded timecode in the picture frame vitc otherwise the classic different clock clicks pops etc would be a big problem, basically the same reason there is house sync and a common sample rate in post production houses.

[ghellquist]

Hi there,
let me expose the limits of my knowledge and just perhaps it is enough.

First Timecode.
The idea (I believe) is that all video and sound is time-coded so it magically sits in the right place in the timeline at post-production. The resolution of time-code is about frame-level 25 Herz or thereabout.

Typically for a modern digital recorder, time code is NOT recorded continously. It is instead used to set the start time for the file. This is sufficient to place the file right in post-production.

For a recorder with a good crystal it is enough to jam the time code a few times a a day, say at day start and after lunch break (or even only once a day). The camera and the recorder will slowly drift away from each other, but in half a day the drift will be perhaps a frame or so.

So in my mind there is no need for a wireless time code system in a typical setup -- just connect a cable and jam once a day.

Then word-clock.
Word-clock sets sample rate. Typically in video work it is "around" 48kHz. Around as there often is pull-up or pull-down used (+ 1% to 48048 is not unusual). Word-clock sync is important if you want to have two recorders recording the same sound.

In my mind that is very rarely done on film shooting. You take all the mics into a mixer and then record from the mixer output. There might be two recorders on the cart, but then often one is backup.

So in my mind there is very rarely any reason to sync word-clock in film work. You have to be very careful in setting the right pull-ups or downs though.

As for the 702T I have not used that one, my unit is a 722. I cannot say enough good things about it. I use it for on-location classic music when I am too lazy (or the client too poor) to carry along the full rack and lots of mics. The sound is really good and it simply works all the time without fuzz. I would believe the 702T to behave well.


gunnar

[Surreal]

You can't sync based in an event? (a beep or something?) if it is more than one video camera you are trying to sync, you could record an analog watch.

wouldn't wireless timecode have even more jitter than regular timecode unless it was incredibly expensive?



(i know very little of timecode and such...just chiming in)

[dkatz42]

Originally Posted by ghellquist

So in my mind there is no need for a wireless time code system in a typical setup -- just connect a cable and jam once a day.

Depends on how you want to use timecode. If you let the timecode free run (so it's nominally synced to time-of-day) then you only need to jam occasionally, or when you turn something off that doesn't have good timecode backup (like the HDcam.) The T-series Sound Devices gear has a battery that will keep the timecode circuit going at full resolution for a couple of hours with the thing turned off (and all power removed.) That battery charges from the main battery/power supply when they're hooked up. Yet another slick feature in that kit.

However, we chose to use record-run mode instead (where timecode is basically a tape counter) as we were single-camera and my video guy finds it a lot easier to deal with when he gets to editing (he encodes the tape number in the hours field, and uses the rest as elapsed time on the tape.) This necessitates feeding camera timecode to the audio side. However, this has the added benefit that the Sound Devices can be set to automatically jump into record when it sees the timecode start to move, which was very handy given the nature of the work we were doing (documentary, "run-and-gun", no rehearsal, 2 1/2 person crew.)

I don't pretend to be an expert in the audio/video integration world, but it seems that trying to slave word clock to timecode would be a recipe for jitter disaster unless the timecode was really solid and the PLLs were really good. But ultimately if all you're looking for is lip-sync, free-running the wordclock should be way more than accurate enough as long as the frequency on the recording device and in postproduction are both tight enough.

Having house sync and word clock distribution (and having one derived from the other) at postproduction time seems like it is going to be necessary to make all of the pieces play together nicely, particularly since ultimately the audio and video need to end up on the same medium. But this would appear to be a different issue than trying to slave timecode and word clock in the field. Perhaps a post guru can chime in and set me straight here.

[dkatz42]

Originally Posted by Surreal

You can't sync based in an event? (a beep or something?) if it is more than one video camera you are trying to sync, you could record an analog watch.

That's what the clapper was/is for.

But for work where you're not setting up shots and don't have a large crew and all that, having a passive mechanism for keeping audio and video in sync is a real boon. And even if you have an event by which to align audio and video, it's a pain in the butt to do that by hand for every shot.

Originally Posted by Surreal

wouldn't wireless timecode have even more jitter than regular timecode unless it was incredibly expensive?

It's basically just an audio signal and it's only accurate to a timecode bit (1/80th of a frame if memory serves) so sending the audio over the air isn't going to be any worse than over a wire. Keep in mind that timecode isn't generally used as a continuous synchronization signal, but rather a way of getting a bunch of free-running timecode generators to agree on a value at a particular point in time (jamming) so jitter in that case is a non-issue.