low audio levels on HVX

[mainstreetprod]

When recording audio, I manually adjust the levels for the peaks to generally fall between the two lines on the viewfinder audio meter. This results in a level
that seems to be on the low side. It sounds fine, but typical MP3 file placed on the timeline is much louder and has to be turned down a lot for the camera audio to be heard. I never seem to have distortion, even when maxing out the meter. Any idea what is going on?

 

[Arson]

1. Never put mp3s in your timeline, use wav or aif
2. If your camera is far enough back to get a good shot then the onboard mic is too far away to record anything clearly, you should get a boom and recorder or a wireless.
3. Don't judge levels based of mp3s of music. Most CDs these days have the audio levels artificially raised so because some people in the music industry think sacrificing audio quality to make a CD play louder will fool the consumer into thinking it is better. it is a trend called the loudness war. http://en.wikipedia.org/wiki/Loudness_war

 

[Ted Spencer]

Arson's right. Commercial music releases are insanely overboosted level-wise (I do music recording, mixing and mastering for a living). The loudness war is real, tragic, and sound quality is being massively destroyed as a consequence, for no real benefit. All it's gotten us is a pointless "mine's louder than yours" competiton, at the cost of fidelity.

So...like...don't get me started... : )

I haven't done an extensive audio analysis on my HVX yet, but if there's about a 10db difference in the apparent level compared to an MP3 from a commercially produced CD, then that's probably normal. Just turn up the HVX audio's overall level on the NLE timeline to its maximum allowable without clipping the peaks (once you've established your mix), then turn down the music until it sits well.

If your HVX indicates audio capture peaks at between the two upper marks (-14 or so and 0, respectively), then you're doing it right. Average level for most things (inbetween the peaks) should be around the -12 mark.

As a 16bit/48K audio device, the HVX has a 96 db dynamic range, so even if the levels are on the low side you should be able to boost them sufficiently in the NLE with a relatively minmal penalty in quality.

 

[Barry_Green]

The two marks are -20 and -12. If you're setting your levels between those two marks then yeah, you're getting really low levels and also not using much of the HVX's dynamic range. Set your levels so that your peaks occur around three dots past the second mark, so your average levels are more like -6 to -9 and you should be much happier.

 

[mainstreetprod]

Thanks Barry- valuable info- I suspected, since I almost never get distortion, that I could let the peaks run a bit past the second line and get some more dynamic range. Glad you clarified that.

I posted this after viewing several DVD's of footage for a TV show that I shot,
but someone else edited. The audio from the camera was usually on the low side, and not that great sounding, compared to the music he adds or his added voiceovers.

However, after looking at the original footage again, the audio seems to be fine. I have been pleased with most of the audio of my own projects, using the
same shotguns and lavs as for the TV show. I will check with the editor and see what, if anything, he is doing differently in FCP.

Arson: I never use the camera mic- only externals. And I meant to say AIF files, don't generally use
MP3's without converting. Regarding the "loudness war", I suspected it but was not aware of any
writings on it. Will check it out. That really explains a lot - although I don't understand how engineers
can boost levels that much without distortion.

 

[Ted Spencer]

I should have made it clearer that I meant between the upper mark (-14, or -12 as Barry says) and the mark at top of the scale (0db). So if you're peaking at -6 or so, and averaging at -12 or so, you're good to go.

Better to be on the low side though, and clean, than on the high side and clipping. Hard digital audio clipping is basically catastrophic and unrepairable. The dynamic range on a shoot can be *insanely* wide, especially without any AGC or audio level compression, which, as far as I know, the HVX does not have. You really have to watch out for massive peaks on loud dialog, door slams, etc. If keeping all of that clean makes the average level lower than ideal, you can still work with it later.

It sounds as though the editor on the project didn't handle it very well. If it was adequately miked and free of noise and distortion, it's a pretty simple matter to raise the gain (and add compression and EQ as needed to smooth it out) to make it sit well with any other audio.