Audio advice for recording a lecture

[Joe Riggs]

Hello,

I will be filming a panel of 4 speakers and I'm trying to figure out my game plane for recording audio.

I’d prefer to figure out a setup where I could run the mics directly to the camera (to avoid syncing) if possible but since the camera has 2 xlr inputs and this will feature 4 speakers I don't know if that will work.

I guess if the speakers are stationary, we could run the mic feed to the camera or place our mic on the podium. Maybe use a mic splitter? Would a dynamic mic on the podium be the best for this scenario (I have a shotgun, lav, and H4N as well. However, I am willing to rent some audio equipment if necessary.)

Thank you

[Noel Lising]

Joe, since they have 4 mics I assume they have a board/mixer in place, I suggest speaking with the AV guy about getting a feed from the mixer to your camera.

My 2 cents

[James Kuhn]

Ditto...take the feed from the 'board'.

Regards,

J.

[Garrett Low]

Ideal situation would be to have 4 wireless lavs, one on each panel member, and one mic separate mic for audience members questions. That mic could be a condenser or dynamic. Take each mic into a digital recorder all on separate channels. Send the mix from that out to your camera(s) via wireless. The camera mix will simply be for syncing. Keep all cameras and audio recorder running with minimal start stops. That will make synching easy in post.

If the venue is providing mics for the speakers you could pull from the board but then you are relying on someone else who is not focused on getting the best audio for video presentation. Also, if the mics are stationary and the speakers turn their heads the sound will vary greatly. Not as big a deal if you're in the audience but it could be very noticeable on your recording and may even drop the audio levels to where you can't hear the clearly.

I would strongly suggest not to try to get all of the speakers recorded on two channels. You want to have the ability to mix it in post. Sometimes the speakers may talk over each other and if you only have the mix you probably won't be able to get it so that you can understand what they are saying.

[Rick Reineke]

A lot of different ways of approach this and have been covered already. A search on this forum should be useful.

[Joe Riggs]

Thanks for the feedback.

Noel,

I'm not sure they will have a mic for each speaker. I believe they will have a podium with a mic and each speaker will approach the podium to do their lecture.

[Garrett Low]

If they will have a podium that each presenter walks up to and another audience mic you could pull the sound from their PA system. For the easiest in post you could send the audio feed to your camera via wireless. If you have more than one camera you could send it to both cameras over the same transmitter.

For safety, I would put a digital recorder also pulling the sound from the PA system and maybe even consider putting a small handheld digital recorder on the podium if it could be hidden.

I believe in redundancy especially when it comes to sound.

[Richard Crowley]

Originally Posted by Joe Riggs

TI believe they will have a podium with a mic and each speaker will approach the podium to do their lecture.

In that case the NUMBER of presenters is immaterial. Only one is speaking at a time. Tap the house system (if there is one, or else set up your own microphone on the podium. Much more straightforward than you made it sound at first.

[Shaun Roemich]

If it is a podium mic, expect at least one presenter to wander away from it muttering the immortal words "everyone can hear me, right? I don't need to use this thing..."

Happens EVERY time. Be prepared for it.

[Rick Reineke]

I'm with Shaun,
There's always some idiot that goes off-mic.
I used to print out a notice to put on the pod and presenters table. This worked much better than word of mouth.. 'in-one-ear-and-out-the-other.'
http://www.dvinfo.net/forum/attachme...1&d=1343402527

[Joe Riggs]

Great info, thanks guys.

I will be tapping into this board and I was told I would need a balanced 1/4 inch to xlr.
Mackie 1402-VLZ3 14 ch. compact mixer [1402VLZ3] - $429.95 : Audio Depot, Madison, WI

The audio guy told me that it will be running "hot", I'm assuming that means near peaking? He also said he can send the signal to me pre or post (I want to say fader but I'm not sure)?

I'll be running that hard wired into the camera (I'll have to do some cable management). Then, my plan was to place an external recorder on stage and a lav near the podium mic or draping off a speaker. What do you think?

[Jay Massengill]

If your camera has a line-level XLR input, then specifically you'll need a balanced 1/4-inch TRS male to XLR MALE cable, then completing the rest of the cable run with regular XLR cables.

However if your camera only has mic-level XLR inputs, you'll need some form of balanced attenuator between the board and the camera.

What camera will you be using?

If the AV person mentioned "pre" or "post" fader send, then they will be using the Aux Sends from the board. Aux 1 is switchable between pre or post fader, Aux 2 is only post fader. Both Aux 1 and Aux 2 send levels are fully adjustable independent of the input faders that are routed to them.

If you want better control of what is being sent to you, your own mixer is really needed between their board and your camera and other recorders.

As mentioned, be prepared for anything and everything odd to happen, so your own high quality ambient mics are important for backup.

Also if you are connecting to AC power at some distance from the house mixing board, be prepared to use some form of safe audio isolation transformer to prevent a ground-loop hum.

[Rick Reineke]

"Also if you are connecting to AC power at some distance from the house mixing board, be prepared to use some form of safe audio isolation transformer to prevent a ground-loop hum."
Yes, an audio isolation transformer is good in any case.
Regarding AC power, don't run mic cables next to power cables and they should only cross at right angles. though with line level you can likely get away with it.