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Advice on ceiling-suspended microphone arrays

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Advice on ceiling-suspended microphone arrays

Postby sallyg » Sun Nov 29, 2020 11:58 pm

Anyone got any advice on setting up a ceiling-suspended microphone array?

I'm planning on putting AB60 omnis on a stereo bar suspended with two wires attached to the sides of a cathedral. It would be good to add two extra cardioids out the left and right too.

Any tips about what wire you should use? Steel rope? Presumably it's best not to suspend with the microphones' XLR cables themselves. Is a 1mm wire enough for two pencils, a stereo bar and their cables? I want it to be as discrete as possible.

The span is about 25m and the drop about 7m.

Thanks!
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Re: Advice on ceiling-suspended microphone arrays

Postby Hugh Robjohns » Mon Nov 30, 2020 1:10 am

I fear this is a case of, if you need to ask on a public form, you're not qualified to do it!

There are serious Health and Safety requirements involved in this kind of rigging (in the UK/EU) and trebly so if there is an audience under the rigging during the recording. The relevant regulations are the ‘Lifting Operations and Lifting Equipment Regulations 1998’, otherwise known as LOLER.

I would recommend attending a professional rigging course to learn the correct and safe rigging practices, the selection of appropriate gear, and the legal requirements and implications.

Most venues will require evidence of competence to perform this kind of rigging, and certification of the rigging equipment. You'll also need to know the maximum loading weights/forces and pull angles of the side wall fixing points to be certain they are sufficient for the requirements.

There are several specialist rigging companies that could advise... But I can say that neither standard mic cables nor 1mm wire would be adequate!
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Re: Advice on ceiling-suspended microphone arrays

Postby zenguitar » Mon Nov 30, 2020 1:36 am

And with your upcoming event in mind...

Some organisations/venues have a rigger on their staff, but the vast majority of riggers in the business are freelancers. When I was crewing in the 90's my crew boss was a rigger, and I introduced a friend of mine who subsequently became a top rigger as well. Of course, my contacts have lapsed in the subsequent decades, and would probably be out of date anyway, but the industry runs the same way still.

Covid has had a massive impact on the live music business and there are many freelancers who have had little or no work since the spring. So there is a pool of qualified professionals out there eager for work. Your local theatres, large music venues, broadcasters, PA & lighting hire companies should have contacts for qualified freelancers, or might even have qualified volunteers prepared to help.

Andy :beamup:
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Re: Advice on ceiling-suspended microphone arrays

Postby sallyg » Tue Dec 01, 2020 11:08 am

Oh!

Thanks for this guys. Sounds like a might be sticking with stands...
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Re: Advice on ceiling-suspended microphone arrays

Postby Hugh Robjohns » Tue Dec 01, 2020 12:35 pm

This is such a tricky one.

A lot of churches/cathedrals/other venues aren't happy with floor stands because of the risks of members of the public tripping* on the stand legs (especially where tripod stands are used) and of tripping on cables running to the stands. And sometimes also because of fears of obstructed sight-lines and maybe even their necessitating the removal of some seats to accommodate them in the right places.

In such cases, flying mics on catenary wires seems the obvious solution -- and it often is in the right circumstances -- but there are equally strict safety requirements involved as I've said, and there are very real dangers involved, just as for floor stands.

Added to which you have the (not inconsiderable) expense of buying/hiring the appropriately certified rigging tackle, and the need to have an empty floor while rigging and de-rigging, plus at least one or two competent/qualified assistants to do the job -- all of which greatly extends the setup/get-out times.

And if your positioning guess turns out not to be ideal and you subsequently discover that you need to move the mics forward or backwards you're in a whole new world of pain and delays...

My preferred solution in such circumstances is one or more Ambient Jumbo Boom Pole(s):

https://ambient.de/en/product/qp-jumbo-boompole/

Image

Mounted on a substantial Manfrotto tripod base at the side or rear of the stage, the jumbo can easily reach up and over the musicians/audience to suspend a mic (or mic array) exactly where you need it. You then have all the sight-line and clear-floor benefits of catenary suspensions, but with the rigging convenience and speed of floor stands. Highly recommended!

They aren't cheap -- you're looking at £1,300-1,600 for a complete rig depending on boom size -- but if you do this kind of thing a lot they pay for themselves pretty quickly. I wouldn't be without mine!

*Public Liability Insurance is an absolute necessity of course whenever doing anything like this. You can buy it yourself, but it is often included with memberships if professional bodies like the MU, IPS, and so forth... The last thing you need is a little old lady tripping on your mic stand and breaking a hip, and then her money-grabbing relatives pursuing you for £1 million in damages.... Seen it happen (not to me, thankfully!)
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Re: Advice on ceiling-suspended microphone arrays

Postby ore_terra » Tue Dec 01, 2020 1:10 pm

I'd go the qualified staff route rather than stands. despite it might sound complex and you dont feel like involving extra personnel, yours is not a difficult job for the right person. you'll get it done easily.

also, as Hugh says, stands might cause problems, or be a problem. and I presume the price of suitable stands (look at those booms!! :crazy: :crazy: ) will be quite high anyway, if not higher than a qualified technician.
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