Proper Field Mixer Levels without Limiters

egproductions

egproductions

Veteran
I'm fairly new to the Mix Pre-D and noticed that it has 20db of headroom on the levels. Should I be aiming to have to levels as close to 20db as possibly (without clipping) or will it sound better to keep it around 0db (and then raise my recorders gain just under 0db). Thanks
 
Providing the 'preamp>recorder' combo is calibrated properly (0VU = -20dBFS)... up to +20dB on the SD, leaving enough headroom for peaks. SD limiters are very good and should be engaged, which will 'catch' an occasional unexpected peak.
 
egproductions said:
I'm fairly new to the Mix Pre-D and noticed that it has 20db of headroom on the levels. Should I be aiming to have to levels as close to 20db as possibly (without clipping) or will it sound better to keep it around 0db (and then raise my recorders gain just under 0db). Thanks
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It's easy to get confused by the differences in the scales used by most cameras and digital recorders, and the SD mixers. Most cameras / recorders are showing you a digital scale that tops out at 0dB and anything above that is a solid clip. The SD scale is in VU. Not at all the same thing.

Here's how it seems to work. You use the MixPre-D to send tone to your recorder. Set your recorder to show this tone at -20dBfs. Now you can forget the levels set on the recorder and only worry about what happens at the mixer. And the mixer you set so that you record just barely into the red. With a MixPre-D that's +10dBVU. Then set your limiters to +18dBVU or +20dBVU. Done this way, it's just about impossible to drive the recorder to clip anything, and you record good strong levels and good s/n levels.

If you insist on looking at the levels at the recorder, you'll see it peaking around -10dBfs, maybe a little higher or a little lower depending on how careful you are with the levels at the mixer. But you'll be in the sweet spot, which is what you want.
 
Very Good, I believe I understand. For controlled shoots I will set my limiters to +18 or +20DBVU just as a slight safety measure with minimal compression. I'll try to aim for right under +10dbvu with peaks at 18dbvu. For event work where I need a lot of range I will set my limiters to +4dbvu which will give me a lot of compression when needed (albeit a weaker signal and more s/n).

Thanks!
 
egproductions said:
I'll try to aim for right under +10dbvu with peaks at 18dbvu.
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No. Peaks just into the red at +10dBVU. This will give you head room for the unexpected, like a loud spontaneous laugh, a hand clap, whatever.

You want the limiters there as a protection -- an insurance policy. You don't want to ever activate them on purpose.
 
Setting the SD limiter to +4dB will result in excessive limiting and can induce distortion. If you ride the levels lower, than you have low amplitude issue, and the levels will need to be brought up in post. .. and with it, the noise floor.
 
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