audio data reading on Sony DSR 11 deck
 

Hello.

Can anyone tell me the nature of the audio data readout, generated by a Sony DSR 11, that appears on a TV screen when the deck is playing back a miniDV tape. The manual gives no explanation. In the bottom left hand corner, along with information like the shots F-stop etc., is a db reading. As I watched material recorded at about -12dB on the digital camera's scale the reading on this screen would be 0db usually. Sometimes I'd see a 3 or 6db. Could this be an analogue readout. Certainly it doesn't correspond to the camera's digital read out and I've only recently come to understand, when I bought a mixer, that some audio devices still give readings on the old analogue scale. I'm confused.

Thanks.

John

I'll take a stab at it, since I own a DSR-11.

I never had anything displayed during tape playback, except 48khz Mini DV, since that's what I work with. I thought the on-screen stats would only be displayed with footage shot with Sony brand MiniDV or DVCAM cameras. When I've imported tapes, I only make sure that I'm in the correct track pitch mode, MiniDV or DVCAM, locked audio, and 2 channel 48khz.

However, I would say that it seems like the deck is giving you an analog readout, since 0DB would be clipping if that was a digital scale. I think the conversion from analog to digital is generally 0db (analog)= -20db (digital); say if you had an older analog mixer hooked up to a digital video camera, you would want to set the levels for that, and then record reference tone.

I wouldn't be concerned with it. If audio was recorded, on the digital scale, which I'd say it was, then what you should check are the audio meters on the NLE editing program that you use when digitizing/ or playing back the footage.

If you digitize through firewire that sends a perfect digital copy. So, unless you have some odd audio capture setting set in the NLE, your audio should match your record levels when you play it back in the NLE; if I recorded audio on a shoot around -12db, then the audio meters in the NLE should read back -12db, since NLE use the digital scale.

Just one of those things where you have to learn to trust your ears more than the meters, and which meters are telling the truth ;)

The dB figure shown is the camera's sensor gain and isn't related to the audio. If you recorded the original material with automatic gain then you will see the figure change. 0db = unity gain. The f-stop and shutter speed also change a lot in automatic mode.

As far as DV audio goes, by definition 0dB is full scale.