Digital problem

[josesequeira]

Hi, last time i recorded from vm-7200 digital out (sp/dif) to the computer trough Motu 2408 to soundforge i notice that the signal was too low. I´ve set the levels of digital out but does it have to be this way? When transferring digital audio it´s suppose be an exact copy of the original, right? Am i missing something?
Thank you for replying.

[Edited by josesequeira on 08-30-2000 at 14:23]

 

[sonusman]

Ummmm...

Too low compared to what? Are you just comparing the metering? If so, welcome to the wonderful world of non-standardization of metering digital audio!

The metering on most digital units is not Peak Metering, and ofter, it is derived from from the D/A converter, and not from the actual digital audio itself. This can cause you to think that the audio has reached 0db on the converters, where in reality, it may have only got to -2 or -3db! Can you believe it?

Here is an example....

In Wavelab, I can use the L1 Ultramaximizer and set it for a -1 db limit at the output, and with enough compression, can have the music reaching that level very often. So, I have not actually hit 0db in digital at all. But if I send this .wav file through the AES/EBU output to my DAT player, the DAT players meters would show that the music is reaching 0db all the time, which would lead me to think that I have ran out of headroom for recording, where in reality, I have yet another db to go before this happens. Weird eh?

I would in your case trust the metering in SoundForge over your other unit. Software usually derives it's metering directly from the digital information, and not from the D/A converter like a DAT player does usually.

Bob Katz has an excellent article to discusses digital level practices on his web site, http://www.digido.com . You may want to go read it for more info.

Good luck.

Ed

 

[josesequeira]

Thanks for replying

The thing is, the vm-7200 is linked with two vsr-880 ( the rack version, that are good in quality but awful in editing) so i send the signal trough the s/pdif digital out from the console to the motu. Than i have to adjust the output level for recording in soundforge and here are my doubts, i´m not shure how to do it. The problem Sonusman, is that i can´t check the metering in soundforge while recording so i´ve tried a couple of times, first it sound distorded and second too low compared with the original.
And yes C7sus, raising the digital level added noise to the copy.
I believe the vsr-880 records at 24 and the motu at 20 bits, the sample rate is 44.100.



[Edited by josesequeira on 09-03-2000 at 04:46]

 

[RWhite]

I may have misunderstood your last comment, but in my Soundforge (version 4.0) you can indeed monitor the signal strength while recording. You need to check the "Monitor" box in the recording window.