double mics on podiums - a la bush press conference - how?

[honeytone]

I noticed while watching the Bush press conference that there were two mics side by side right in front of him, and it seemingly violated the golden phase rule of 3:1 ratio. How does this process work? Are the mics split to two (or more) separate locations?

I was going to ask Bush himself, but i figured i'd get a pre-calculated heaven and earth response...

thanks everyone for reading.

tony

[dynomike]

When I was working for an events company we used to do this in case 1 mic/cable/channel failed but would actually have 1 mic on at a time, with the other one about 20db down. If you are actually running 2 mics together, you should tape them together in the centre.. this works well with those podium mics on goosenecks.

[coniferouspine]

I was thinking one for recording and one for the PA or whatever amplification was in the room, but dynomic's answer makes more sense. I don't know why there'd be a need to record the President in stereo -- it might reveal that his voice is actually coming from the direction of Cheney's throat. Ever see Cheney drink a glass of water while Bush is speaking?

[stuntbutt]

I've wondered about that also. I have noticed that sometimes there are even 3 mics bundled together! Maybe the mics are for seperate redundant feeds? Perhaps one mic for archive, one for PA and one for the press? A transformer split would be a lot simpler! And when was the last time that a 57 stoped working while sitting on a podium? My theory sucks.

[aurelialuz]

wasn't there some thing with the grateful dead's sound system where they had two mics, and it was something like a balanced cable, the difference between the two was cancelled out, eliminating noise or something? if you watch live dead videos from the late seventies, you'll see what i'm talking about. i always assumed the president's mic worked on this principle, but it seems a lot more likely that it's a failsafe against one going down.

alex

[stuntbutt]

That Grateful Dead double mic is probably one for the PA and one for the recording. That's the deal with the Woodstock movie.

[brew]

If the two or more mics are coincident it does not violate the 3-to-1 rule.

[kcrusher]

Those mics go to 2 different feeds - they're not being used by the same people, thus there's no need for the 3-1 rule. Generally 1 goes to a recorder and the other to a splitter box that goes to all of the news feeds.

[leigh]

No, Alex is right about the Greatful Dead's double-micing being a noise canceling thing. Well, each mic was balanced, so you have that traditional noise canceling. But then they'd put the two mics pretty close together, and put them out of phase, so that stage "noise" (drums, guitars, monitor wash) got cancelled out. Since this is a differential system, the singer has to sing right up on one of the mics, so that the singing is much louder in that mic. Otherwise the singing would be cancelled out as well.

Which means this would not work for a pair of podium mics, both of which are equally distant from the speaker's mouth. I expect it's simple system redundancy in this case, so that if (yeah, I know it's one-in-a-million) one 57 dies, they can switch over to the other one.

Leigh

[bedbug]

wasn't there some thing with the grateful dead's sound system where they had two mics, and it was something like a balanced cable,

"President" Bush is totally influenced by the Dead.

[aurelialuz]

thanks leigh, i had heard something about that a long time ago but didn't remember how it worked.

alex

[cgarges]

Backup, anyone?

Chris

[stuntbutt]

Wow, that Grateful Dead mic technique sounded pretty crazy until I remembered the "wall of sound" concept they tried.

[Scodiddly]

Reliability is a big concern, so that's why they have two or more mics. One is a hot spare... I helped set up the 1992 debate in one of the venues, and they had three mics (disguised as one) on each podium, three cables back to the three mixers (one mixer and small PA battery-powered in case both of the backup generators happened to fail). They were really serious about not having any technical interruptions to the debate.

[OneZero]

Just Curious-

Has anyone ever experienced a SM 57 failure. How about without throwing it a the wall?