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[Chris Grimshaw]

I agreed to do an event without fully realising the size of the venue. A clever move on my part, to be sure.

The PA system I run is pretty reasonable, with 4x 15" ported subs loaded with Faital Pro 15HP1060 drivers, and 2x 2x10" tops with FP 10FH520 and 18Sound ND1460 drivers on a 90x40 horn. Tri-amped with Behringer iNukes, around 1KW for each 15" and 10" driver, and 300w for the HF. A fairly solid small-format setup.

You can imagine what went through my mind, then, when the venue was a rugby stadium. For those of you based in the Land of the Free, rugby is like your football, but with less padding and more blood.

Anyway, I was told by email we were firing along the length of the pitch, so I was planning delay lines (some 12" coaxial monitors), which would go nicely where the covered seating is, about half-way down the pitch. On the day, I was told it would be across the pitch, and they wanted the setup arranged in a way that it would've been awkward to deploy any delays.

I was worried while I was cabling everything. Pushed the fader, and this happened:

https://www.youtube.com/watch?v=ZXuV-Cl0hmI

At that position, the SPL meter was reading 85dB, C-weighted, slow response, at somewhere around 250' from the speakers.
The PA is just about visible, and this was just about tickling the limiters.

I was grinning for the rest of the day.

Chris

[Steve Alves]

It is always amazing what getting them up in the air does.

[Art Welter]

At that position, the SPL meter was reading 85dB, C-weighted, slow response, at somewhere around 250' from the speakers.
The PA is just about visible, and this was just about tickling the limiters.

I was grinning for the rest of the day.

Chris

Chris,

Now you appreciate the inverse distance law works, it is also easy to work out each stack only had to do around 117 dBC slow at one meter to achieve that level down "power alley".

Physics is Phun!

Cheers,

Art

[David Buckley]

... the venue was a rugby stadium. For those of you based in the Land of the Free, rugby is like your football, but with less padding and more blood.

You are aware that The Yanks are the current rugby Olympic champions...?

[Chris Grimshaw]

You are aware that The Yanks are the current rugby Olympic champions...?

Not at all. I don't follow sports much, just thought some clarification might be needed.


Art, 117dB C-slow doesn't sound like much!
Analysing the track, though, and it looks like the RMS level (according to Audacity) is around 18dB down from the peaks. If the meter set to "slow" tracks Audacity's RMS level reasonably closely, then it's possible the stacks were touching the limiters at about 135dB peaks, give-or-take a few dB to account for C-weighting and the fact that the last dB or two was lost by going into the limiters.

That'll do for me, anyway.

I did take the MF-HF crossover up from 800Hz to 1.2kHz for that particular event. 800Hz gives nicer polars, but I'd much prefer it if the HF drivers survived the gig.

Chris

[Ivan Beaver]

Now you appreciate the inverse distance law works,
Physics is Phun!

Cheers,

Art

Inverse square law can be your friend or foe-depending on how it is looked at and from what perspective.

[dick rees]

It's not the rig that is surprising so much as what you can hear when the ambient noise level goes down below 40dB.

On 9/12 when the local airport (MSP) was shut down and the freeways were almost deserted, it was like being back on the farm in Iowa in the 1950's.  The loudest thing was the birds sining...

[Don T. Williams]

It's not the rig that is surprising so much as what you can hear when the ambient noise level goes down below 40dB.

On 9/12 when the local airport (MSP) was shut down and the freeways were almost deserted, it was like being back on the farm in Iowa in the 1950's.  The loudest thing was the birds sining...

The birds were sining rather loudly I assume!

[dick rees]

The birds were sining rather loudly I assume!

Sorry.  Right letters, wrong order.

Singin'...

I had the "g" in the wrong spot.  Typical male...

[Chris Hindle]

It's not the rig that is surprising so much as what you can hear when the ambient noise level goes down below 40dB.

On 9/12 when the local airport (MSP) was shut down and the freeways were almost deserted, it was like being back on the farm in Iowa in the 1950's.  The loudest thing was the birds sining...

My office is beside Montreal's international airport. Both main runways were in use that day.
At one point I looked up, and i could see a string of 20 sets of landing lights for each runway. No idea on how many were circling out of my sight.
Don't know where they all got parked, but it was a busy day at the old airport. At least up here, no one had the bad manners to park a plane in a building.
Chris.