flat audio waveform display

megabit wrote on 5/3/2008, 5:05 AM

When I set my EX1 audio gain to manual at 5, and with the input sensitivity dialed down to some -38dB in order to avoid distortion, discussed elsewhere - after loading clips into Vegas time line, I'm getting flat line for most part of my audio (apart of course from some really loud environment / events).

This is a very basic question, I know - but is there a way to rescale the display up without changing the track height itself, just for easier viewing purposes? Funny thing is that when I had the same problem with the V1E with the stock mic, I attributed it to the "lousy" audio section / microphone low sensitivity !

When I watch the same clips on Edius time line, the waveform is much higher (I guess it logarithmic mode)...

Comments

blink3times wrote on 5/3/2008, 5:35 AM

If you right click on the wave and go to "switches" you will see a "normalize" option towards the bottom... turn that on and it will help a little.

farss wrote on 5/3/2008, 6:09 AM

Ah, no! That'll increase the gain so that the peaks are at 0dB!

Hold down the shift key and use the up/down arrows to zoom the height of the waveforms. Note that if you have set Vegas to build 8 bit peak files and you zoom in a long way it might not look too pretty.

More of a worry though is why is the audio so quit.

Bob.

megabit wrote on 5/3/2008, 12:51 PM

Thanks Bob - right on BOTH points (as most of the times:))

As I said in the discussion on DVINFO, setting the input to some -38dB and using manual GC can help avoid cracking distortion, but indeed the audio is not "nice and loud" any more...

farss wrote on 5/3/2008, 3:58 PM

I *think* I might know what's going on with the EX1's audio. We first noticed the same problem on the V1P!
Need to do some more testing but I suspect the problem does relate to how both those cameras are doing their phantom power and the mic / mic cables grounding arrangement.

Bob.

megabit wrote on 5/4/2008, 1:13 AM

Bob, can't wait for you revelations!

It so happens that I will be soldering a new short cable for my Edirol, anyway (because of other reasons), so I'd appreciate it if you share your findings with us before I do, so that I could consider it when preparing the new cable.

Piotr

farss wrote on 5/4/2008, 2:11 AM

I have mentioned this before here:
http://www.sonycreativesoftware.com/forums/ShowMessage.asp?MessageID=589974
and on DVInfo.

It seems as though the ground pin needs to be left floating from the connector shell or the mic may not work.
If you read about half way down on this:
http://en.wikipedia.org/wiki/XLR_connector
you will find this interesting part:
"Note that neither the standards nor manufacturers agree on the best way to handle the usage of pin 1 at both ends of a cable, particularly with respect to the cable shield, the connector's shell, signal ground, and a third cable wire connected to pin 1 — which may (or may not) be connected to the shield."

A very quick look at our stable of mic leads shows some do and some don't have pin 1 connected to the connectors shell and it's not something one normally notices. I'd also point out that the return path for the phantom power is the shield.

This may have nothing to do with your problem but it's certainly an issue worth further investigation plus it's in line with a comment from Audio Tchnica about the EX1 having some wierd grounding arrangement.

Bob.