Michael Romano
01-27-2009, 12:33 PM
So I've been doing some testing trying to figure out how to get useable synch sound out of the RED camera and what a hassle this has been! I think I've gotten it working quite well but there are still questions to be answered.
EQUIPMENT:
1 - Sound Devices 422 (3ch mixer) which has been reset to factory settings
2 - RED one, Build 16, original audio module with the RED supplied XLR > Mini XLR cable (Padded if I'm not mistaken)
3 - FCP 6.0.5 on Intel Mac
4 - ProTools LE 8 with DVTK2 (Digitranslator function used in this workflow)
HOW IT GOES DOWN:
Arm the input and set it to line level (You cannot adjust the line level inputs!)
Set the 422 outputs to line level and turn on tone. It reads 0VU on the 422.
Look back to the RED and tone is just a pinch above the 2nd mark from the left
http://www.reduser.net/forum/uploaded/13889_1233088196.jpg
Record a few seconds of just tone.
Then feed a second mixer's tone output through the 422 and gain it (On the channel, not the master) up to just below peak on the 422.
This is where I found that you cannot peak past +18dB (On the 422) or else it clips on the RED.
Back it off very slowly until the RED is no longer clipping and record a few seconds of this as well.
Then load both clips into FCP via proxies.
Low and behold, the levels are way out there! What was a hair below a clip on the camera now reads as -6dB. The tone reads at -25dB.
After a bunch of head scratching I exported a 24/48 OMF to ProTools.
Surprise!
ProTools reads tone at -18dB and the peak at a hair below clipping. This is more like it!
But why? What the *Hell* is going on here? FCP is not monitoring properly according to this test.
In ProTools, anything above 0dB is toasted. There is NO headroom in that area! How is it that FCP has headroom? Everything is set to 24 bit.
I swear, I'm NOT crazy.
Any suggestions would be greatly appreciated on how to make this meter correctly across the board.
P.S.
Here is the check list and results in a truncated form, essentially what I keep on my iPhone for audio guys on set.
On RED: Arm inputs and set to line level
On 422: Set outputs to line level
On 422: Tone reads at 0VU
On RED: Tone reads 2nd mark from left
On 422: Cannot peak past +18dB or else we clip on the RED
Tone on 2nd mark reads as follows:
422: 0VU
FCP: -25dB
ProTools: -18dB
Peak on 4th mark reads as follows:
422: +18VU
FCP: -6dB
ProTools: 0dB (just below clipping)
EQUIPMENT:
1 - Sound Devices 422 (3ch mixer) which has been reset to factory settings
2 - RED one, Build 16, original audio module with the RED supplied XLR > Mini XLR cable (Padded if I'm not mistaken)
3 - FCP 6.0.5 on Intel Mac
4 - ProTools LE 8 with DVTK2 (Digitranslator function used in this workflow)
HOW IT GOES DOWN:
Arm the input and set it to line level (You cannot adjust the line level inputs!)
Set the 422 outputs to line level and turn on tone. It reads 0VU on the 422.
Look back to the RED and tone is just a pinch above the 2nd mark from the left
http://www.reduser.net/forum/uploaded/13889_1233088196.jpg
Record a few seconds of just tone.
Then feed a second mixer's tone output through the 422 and gain it (On the channel, not the master) up to just below peak on the 422.
This is where I found that you cannot peak past +18dB (On the 422) or else it clips on the RED.
Back it off very slowly until the RED is no longer clipping and record a few seconds of this as well.
Then load both clips into FCP via proxies.
Low and behold, the levels are way out there! What was a hair below a clip on the camera now reads as -6dB. The tone reads at -25dB.
After a bunch of head scratching I exported a 24/48 OMF to ProTools.
Surprise!
ProTools reads tone at -18dB and the peak at a hair below clipping. This is more like it!
But why? What the *Hell* is going on here? FCP is not monitoring properly according to this test.
In ProTools, anything above 0dB is toasted. There is NO headroom in that area! How is it that FCP has headroom? Everything is set to 24 bit.
I swear, I'm NOT crazy.
Any suggestions would be greatly appreciated on how to make this meter correctly across the board.
P.S.
Here is the check list and results in a truncated form, essentially what I keep on my iPhone for audio guys on set.
On RED: Arm inputs and set to line level
On 422: Set outputs to line level
On 422: Tone reads at 0VU
On RED: Tone reads 2nd mark from left
On 422: Cannot peak past +18dB or else we clip on the RED
Tone on 2nd mark reads as follows:
422: 0VU
FCP: -25dB
ProTools: -18dB
Peak on 4th mark reads as follows:
422: +18VU
FCP: -6dB
ProTools: 0dB (just below clipping)