Edirol R4 Pro & Red

[Dustin Cross]

Aloha,

I have been testing an Edirol R4 Pro 4 channel audio disk recorder today with my Red.

Syncing timecode was easy. Red Jam synced to the Edirol just fine using the Sound Device Lemo-5 to BNC cable from B&H.

It was easy to name the clips in Edirol to match the file names on the Red media. Or very close anyway.

A012_001.wav - A012_C001_080507

One problem I am having is the Edirol does a weird 24 timecode. Instead of 0-23 it writes 0-60 and skips numbers so it ends up with 24 frames.

This was a problem at first when I would try to sync 14:12:23:20 in the wav file to 14:12:23:20 in the Red file. My audio would be off. If I sync both to 14:12:23:00 they match perfectly. As long as I sync both to 00 frames the audio seems to be in perfect sync.

Now I am going to do some long record tests and see if there is any drift.

Is there anything else someone would like me to test?


Mahalo,
Dusty

 

[Dustin Cross]

There appears to be drift in the TC between the Red and R4 Pro. A few frames per hour. I am doing some more testing to make sure I didn't do anything wrong.

So my questions now becomes, if the timecode is drifting, is there any reason to use it? If not then maybe I should just look at getting R4 or R44.

The filenames match and I can use a clapper to sync, so how important is timecode?


Mahalo,
Dusty

 

[David Didato]

Thanks Dusty,

How does it handle other RED frame rates like 23.98, 29.97 etc?

 

[Dustin Cross]

clearlighter,

I haven't had a chance to check other framerates. Only 23.976.

The R4 Pro records the wrong timecode a lot. I tell it to be 23.976, but sometimes the files are 59.94.

After more testing it seems like the R4 Pro audio drifts .75 of a frame every 10 minutes.

The timecode is in sync between the .wav and the .mov, but the sound is out.

I was recording the audio at 48k/16bit and the FCP timeline was 48k/32bit. Could that conversion somehow cause the drift?

I need to do more testing.


Dusty

 

[Meryem Ersoz]

interesting...I just purchased one of these but have not had time to test it with the RED.

The testing with the SD 744t also showed some drift. I guess if you can figure out the uniformity of the drift, it is a simple matter to synch. But a pain nonetheless and not what we paid extra money for, as you say.

Looking forward to more of your testing results.

 

[Keith Nealy]

Aloha Dustin,

I think you may be right about the different resolutions having an effect but only a test will tell for sure.

If you were to use the R4 Pro as an outboard mixer, how do you handle the fact that it does not have +4 balanced outputs?

BTW, Are you in Texas or Hawaii? I'm on the Big Island.

Aloha,

Keith

 

[Dustin Cross]

Keith,

I have been in Texas for a little over a year now. My wife is from Kailua (Oahu) and I lived on Oahu for about 15 years. We really miss home, but Texas is so much more affordable. I come back to Hawaii as much as I can.

I was never planning to use the R4 Pro as an outboard mixer. Just send reference audio to the camera. The R4 has four RCAs out, but I found it easier to just use the headphone out with a spliter to send a reference mixdown to the camera.

The audio coming thru the R4 to the camera was 2 frames behind picture. This was constant and did not drift. Just that much delay in getting thru the R4.

I had to take the R4 Pro back to the rental house before I got to do any more testing.

A couple other tests I would have liked to do is:

1. leave the TC cable connected and see if the audio still drifts.

2. try using a timecode generator to control the TC in the R4. Sync the Red to the TC generator, then connect the TC generator to the R4 Pro and leave it connected.


Mahalo,
Dusty

 

[Keith Nealy]

Thanks Dusty,

I'll be getting my RED in a few weeks so maybe I can do some of those tests.

Thanks for sharing your info. It will save me some time. Hope to see you back in the islands some day.

aloha,

Keith