ALC not independent on the two input channels??

[Baluardo]

Well, the other night i have been filming a concert with my dvx100A.

The audio guys from the mixer were able to give me only a xlr output with the mixed sounds from mics and all instruments.
cool, i've put this into input 2, set on 'line', while on input 1 i've put my ext mic (set on mic) to capture the audience soudns as well.

the idea was to use, in the final editing, the input 2 replicated on the two channels all the time, and use the input from the mic in the parts between songs to hear plauses and cheerings.

well, while the line input (ch 2) was properly tuned from the beginning (volume knob in the middle), the mic ch 1 was too loud for the first 20 secs or so into the first song, then i realized it was clipping, and turned the knob down. i didnt care cause that channel was for plauses only.

when i go to the editing console i realize there's a problem. when the clipping was occurring, the ALC obviously came in the reduce the harshness of the 'uncontrolled' clipping. the funny (or sad) thing is that apparently that affected the other input channel as well!!!! this completely ruined the line recording (the good one) of the first 20 secs of song!! it's like somebody is playing really dumbly and quickly with the volume knob.

- why the ALC doesn't work independently on the two channels???
- what can i do to fix this??

thx
Andrea

[JSF]

I remember reading that somewhere, or I saw it on the Digital Video Expo videos. I'm not sure if that was fixed on the 100b or not.

There's not much you can do to fix the audio you already have, at least, i've never been successful with it.

For recording concerts I really believe that there's no better solution than recording the audio seperately and linking in post.

The best solution would be to invest in a firewire interface to pull individual channels from the board and 1 live "floor" mic and mix it in post. Depending on how much you want to spend there are a couple different sizes depending on the type of music.

Let me know if you want to know more about this option, i'll let you know what my setup for concerts is.

JF

[Baluardo]

thanks for the answer, JF.

I understand recording audio separately would be better, but i did record concerts with the xlr inputs of the cam already and they came out very good. i just happened to encounter an unexpected problem.
- Anyway, yes, I'm interested in knowing more about your live setup, thanks.

- the good news (at least for me) is that I managed somehow to fix quite satisfactorily the 'bad' 20 seconds applying a compressor filter and fiddling around with the controls. I wouldn't say it's top quality, but it's very listenable (the old version wasn't), and I'll use that fading in the good recording after 20 sec.
the only other option i had thought about so far, was to give up that song altogether.

Andrea

[Nathan.Buxton]

good call with the compression filter!!

[downsouth]

Liked your Isle of Man...trailer. Being a biker myself..Id like to visit after seeing your flick.

Thanks for sharing..
Jeff

[downsouth]

P.S.
On the "through the bike windshield shot", how did you mount the DVX for that?

[Baluardo]

thanks, Jeff.
I confirm you that the TT event on the Isle of Man is really a unique experience, especially if you're a biker. This year is the centenary edition (it is on right now actually, for other 10 days or so). They're having 70k visitors (same of the resident population on the island!)

the bike cam was not the DVX I didn't want to risk it. It was a small sony handycam with a wide angle adapter. The mount was a cheap suction-cup-based thing, placed on the tank, and wrapped around with duct tape for extra safety.
That camera proved to be not the best for the purpose, as in the bumpiest parts of the track/road, the focus/zoom went completely wrong for a few seconds. It was like some inner lens lost the right positioning for a while. very weird.

Andrea

[ullanta]

For the record - the "linked" ALC is pretty important for stereo recording - where you DON'T want independent limiting on each channel. It would be nice to be able to link or unlink it; but the DVX setup is pretty good!

[JSF]

Hey baluardo, I told you I'd get you my setup.... sorry it took so long.

I normally run a pair of live mics, one in the crowd, one towards a speaker stack, for my "live" mix (I use some MXL 660's cause they're cheap but sound good with high spls, or an AT2020/Behringer B2 for safer/higher quality). Then I would run the individual outputs (using insert channels via 1/4" or aux sends at nominal gain if they're available) from the board to a firewire interface (I use the presonus firebox, or firepod if it's more than 6 channels) and record using cubase. Then I mix down, get a good blend of direct sound, ambient sound, and crowd noise (crowds for sing-alongs/applause, live mics for natural reverb, etc) to an audio file that I'll import to Premier and link to the video.

I'm glad you were able to fix the original problem though, good thinking with the fx!

JF

[Evro]

A much easier and cheaper alternative is to get yourself a Zoom H4. It has combined XLR/Jack inputs with phantom power and integrated MS stereo mics onboard (looks like a tazer).

I've used it for numerous church gigs and it's worked a treat because I don't have to keep the cams running all the time, the H4 just gets the whole lot. Also there's less vaulnerability & setup time than you'd have with computer based recording setups in a live environment.

If I know & trust the FOH guy and have the space/time to setup a computer based system with outboard mics then I'd go for that instead, however, these oportunities rarely happen especially when I've got to worry about getting good video coverage at the same time.