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View Full Version : inserting L1 while recording VO. OK to do?


TMS
12-09-1999, 06:55 PM
Does inserting the L1 limiter on a Aux track and bussing that track to the record track while recoding live degrade the signal path? My idea is to use the L1 as a safety against digital overs by setting the out limit at minus 1db while I record Voice overs. I'm not talking about slaming the threshold,just using it for those occasional peaks. I just thought I would check with some of you digital gurus out there

Thanks in advance
Cheers
Craig

snoopy
12-10-1999, 07:34 AM
My somewhat humble opinion is that if it's going to peak digitally, it probably is at the analog input stage as well, therefore I personally would rather have any dynamics control before the input to protools (though maybe I'm overlooking a scenario).

TMS
12-10-1999, 09:18 AM
Yes, I do insert a compressor in the console before I go into Pro-tools. I use this for light compression to help keep things under controll. However, when recording very dynamic voice over, such as an actor reading for and audio book, the levels go from a whisper to shouting in a heartbeat. Clients generaly do not want heavy processing so heavy compression on the way in is not desireable and one can only ride the fader so much. Most of the time this is not a big problem, but it would be nice to have that L1 safety for those occasional peaks that get through. The L1 does work in this configuration but I do not know whether sonically this is a good idea. Again I plan to set the out limit a little under digital zero to protect from occasional clips.

Thanks for the response Snoopy

Any other opinions

Craig


[This message has been edited by TMS (edited 12-10-99).]

Rader Ranch
12-10-1999, 09:52 AM
i can't remember offhand what delay is incurred with the L1, but you might wanna have someone in the booth while you click the bypass switch on and off, as many tdm plugs cause quite a bit of delay, and VO talent can often be very sensitive to the fact that there voice sounds all 'effecty' and delayed. You can always set up PT to give them a completely clean feed while using the L1 as your digital safety to disc, which i would personally be comfortable with sonically as long as it's not hit hard.

AdamFrick
12-10-1999, 10:28 AM
L1 is very transparent and I wouldn't think you'd hear anything negative with such minor settings...

I'm confused, though - the audio has to be converted to digital before it hits the aux channel, so haven't you already gone over full scale before you get to the L1? I understand that it will only WRITE the limited version, but won't you hear that clip? Or am I turned around?

-adam

blairl
12-10-1999, 11:06 AM
Someone mentioned recording audio books. When I have done this I will apply no processing on the way in. This means that I must make sure that the peak level they send ,which often includes screaming and other dramatic things, does not PEAK the input. This is one area where the dynamic range of Pro Tools is important. If you do it this way, the regular dialog barely moves the level meters. But you can apply all the compression and limiting on playback that you want, even automating certain sections. This is something you can't do on an aux track on the way in.

TMS
12-10-1999, 01:54 PM
Good point Adam. Seems to me,anything over full scale would clip the converter before it even reaches the L1. I'll test it today before the session. Maybe a Rosseta with soft limit would do the trick. I'll have to save my pennies.
I'll reprt back what I find out.

Cheers Craig

Fokke van Saane
12-10-1999, 02:57 PM
I do a lot of filmsound recording on the set and i know way to well how actors can be unpredictable, so i understand your concern about crossing the zero. Actually, in practice it isn't such a big problems but it depends on the AD how it handles overs. On the set i use a Fostex PD4 portable DAT and it is very gentle with an actor screaming into the overs. Actually, i let him do it. When i try to keep everything out of the overs and don't want to risk an over i find myself recording way to low-level. I prefer the use the full bit-scale. The only thing that is very noticeble is a female high pitched voice, that is the worst in an overload. But percussive sounds, an outburst or whatever, i don't care much.
When you do as you tell us, a finger on the fader followed by a compressor before the AD i think it would do the job. And if you still don't trust your fader riding skills you can always record on a second track 6 dB lower, ie. split the mike and lead it to a second AD converter.
Don't be scared.
Fokke.

TMS
12-10-1999, 04:40 PM
Thanks Fokke
I'd say 98% of the time I'm able to stay safe by riding the fader and sometimes the pre,along with easy compression.I also, like you suggested, run a B/U dat with one side down 6db or so. If I'm going straight into pro tools I'm always running one or two dats for b/u.(I'm a fanatic about b/u's)
On paper,(or somewhere in my head) the L1 idea seemed to make sense. But Adam was right earlier in this thread when he said the L1 would be after the fact. If you cross zero in the pro-tools converters the deed is done before you reach the L1.
Actually, Pro tools has quite a bit of headroom.
Oh well, so much for my hot idea:-)
Thanks for the feedback guys

Cheers
Craig

Rader Ranch
12-11-1999, 12:59 AM
good point, Adam. the only way to be safe is to use an outboard A/D with a built in limiting feature. otherwise your goal is just to set up the analogue processing to use as many bits as you can in dig. without clipping the exciting parts or overcompressing the whole thing....to state the obvious...

AdamFrick
12-13-1999, 06:49 AM
one last thought craig -

the soft limit rocks my world (using an ad8000). I put it on for anything I'm recording. That allows me to get pretty hot levels and not freak out about overs, cause I know softlimit will catch all but the worst.

fwiw, I'm working in children's videos here (computer animated - think Toy Story) and so the talent is often in a hyper-active character voice, and they're always blowing up the mics or pres before I can even let softlimit do its work! Sure, tube distortion is great, but not on dialog!

:-),

adam

Jules
12-13-1999, 07:48 AM
I've always thought the Live recording guys trick of getting a 2nd version of the L vocal 6db down was cool, Fokke is right, that route is bullet proof, try it, then your covered for anything that comes at you.
Jules