Complex mics array - Question for JW

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Chrome
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Joined: May 26 1999

Question for John W...

Hi John,

Just looking for a few pointers. I have a freelance sound engineer within my crew, but would appreciate any suggestions (a second opinion) as this problem is fairly complex.

I am putting together a solution for an overhead 'matrix' of mics to cover a council chamber and pick up all the potential speakers for broadcast/recording and internal re-enforcement PA purposes in a very challenging environment.

There are a number of curved differing length rows of fixed chairs on a stepped arrangement (think a bit like cinema seating), with six chairs at the front, followed by rows of ten, twelve, sixteen, sixteen, twelve then two straight rows of ten (I think) at the back. The chamber is also used by the public for other purposes during times that the council is not sitting, so all mics must be in a position they cannot be interfered with, so mics for each seat is out of the question (the budget would not cover it anyway). There is also a table at the front facing towards the rows where the chair etc. will sit.

The space for 'crew' is extremely limited. We are putting together a small remote multi-camera broadcast system two cameras to be operated by the vision mixer/remote cam operator and one cameraman. We cannot afford to have a full-time audio mixer on the job as well, even if there was space (which there will not be). Which means once the system is switched on, the levels each mic is set to should not really be changed.

So all that said and done, we need to place mics strategically to pick up each 'talker'... I'm planning on stringing a series of overhead wires as a matrix to support a series of high-quality overhead mics; probably around 12 to 15 units overhead and two for the front table, so potentially 17 (perhaps even more) mics. I was looking for a Sennheiser solution, but can't see ny mics applicable to what I want. Was also hoping for them in white :)

MAGLINK
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Joined: Mar 8 2007

Hmmm 17 mics all live at the same time that will not sound good at all there will be a lot of noise and it may be better to rig a few PZM mics instead.

To throw PA into the equation will make it even worse and the sound will be rattling around like the clappers. I have been in some court chambers and the mics are usually in front of the key positions but never more than about 3 or 4 mics.

Have a look at the houses of parliament they have mic capsules suspended above the chamber but also have a permament sound mixer fading up the revelant mic to who is speaking. The only PA in there is the small speaker in the seat backs so that the member on the opposite side can hear the speaker (or fall asleep looking like he is listening)

This isnt easy even for a pro sound guy and I will be interested to see if JW can think of a solution. As said having 17 mics open and PA fed at the same time will just be chaos and it may be better to keep it simple with a few PZM's overhead. Having said that PA will still be problematic.

Chrome
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Joined: May 26 1999

I realise what I'm currently suggesting is not very elegant, but I'm just looking at various ideas until my sound guy takes a look at the situation.

The 'real' problem is not having a live sound mixer, but locating them within the chamber. We literally have about 1.5m square to locate the vision mixer and relevant equipment as well as the manned camera operator and equipment. All the VM equipment and manned camera equipment will be built for rapid deployment/breakdown as we will only have about 1 hour to deploy each time we use it and it may take us 20 minutes from getting access to the building just to get to to the chamber. So all this being said I intend the 'sound reinforcement PA (likely to be a high-end quality solution like Bose) and microphone matrix (or whatever we decide) to be permanent install. With the rest of the equipment to be brought in as a rack and plugged in... a simple test then ready to go. Re-setting mic levels will probably be out of the question. If money was no object I know what I would do... have a touch-screen with zones set up and as the operator touched a zone that mic would go to a pre-set level, at the same time muting all the other mics. This could then be done in seconds at the same time as vision mixing. :D However I doubt we have the budget to design and build the software in addition to the hardware.

DAVE M
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Joined: May 17 1999

I've never used them but there are "automatic" mixers for conference use. I don't know if they'd cope with the political cross shouting

http://www.compositevideo.co.uk/product-detail.asp?id=723&catid=161&manid=93&nlid=0&quantity=1

Chrome
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Joined: May 26 1999

That's a brilliant piece of kit Dave, Thanks :)

DAVE M
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Joined: May 17 1999

Composite aren't the cheapest but they're ok guys.

I believe that Sony also do something similar

have a shufftie at Canford Audio and Studiospares.

John Willett
John Willett's picture
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Joined: Jun 1 2001

Hi Chrome,

I must have been passing your front door when you posted this - I had to go to MK twice last night.

I have just sent you a PM - give me a ring and we can talk through all the options.

Many Councils actually have conference systems with PTT microphones and it may be possible to take the direct output from the Central Unit.

Anyway - give me a ring and we can discuss.

John
 
A picture tells a thousand words, but sound tells a thousand pictures.

MAGLINK
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Joined: Mar 8 2007

One possible idea could be a rack of cheap behringer noise gates with soft knee attack and release that would then only open up any mics that are within level threshold of the speaker.

It would take a lot of setting up but may be a lower cost option.

As already said a conference system with the button and light arrangement as seen in brussels might be an option but it also relies on the speaker turning the mic on in the first place. Canford may be a good source of advice too.

DAVE M
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Joined: May 17 1999

whatever the solution, can you post a summary of what you used in the end?

You never know when it'll come in handy!

Dave R Smith
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Joined: May 10 2005
JGNattrass wrote:
As already said a conference system with the button and light arrangement as seen in brussels might be an option but it also relies on the speaker turning the mic on in the first place.

..like the one in the Bond film with a translators audio return which can be substitited with a fatal high requency signal?:D

Gearhouse broadcast are selling off 2008 games hardware - may also be able to offer advice for solution as they specialise in bigger projects.