Advice on JBL VERTEC 4887

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Idan Pi

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Hello everyone

I'm new to this forum, my sound company is considering buying 12 units of JBL 4887 (6 per side) for rock concerts of 8000-15,000 crowd.
Is the 4887 system suitable for this ?
we are planing to run this with our EAW SB 850 subs.

Thanks
Idan
 
Re: Advice on JBL VERTEC 4887

Idan Pi said:
Hello everyone

I'm new to this forum, my sound company is considering buying 12 units of JBL 4887 (6 per side) for rock concerts of 8000-15,000 crowd.
Is the 4887 system suitable for this ?
we are planing to run this with our EAW SB 850 subs.

Thanks
Idan
Click to expand...
The 4887 can only do around 100 dBA at 20 meters (65 feet). OK for wide dispersion, relatively short throw, lower volume work.
For "rock concerts" with 8000-15,000 people you should be considering at least 12 units of the 4889.
 
Re: Advice on JBL VERTEC 4887

You must have a radically different idea of "rock concert" and "coverage" than we do... How many people do you actually need to cover in this presumably enormous space?

I'm more worried about the SB850, decent box but not high output by modern standards. Unless you have, say, 32 I think you're overselling your company's abilities.
 
Re: Advice on JBL VERTEC 4887

No.

We own both 4887 and 4889, and for arena work up to 12,000 or so we take 12 4889 per side and 8 4887 per side for the LL/RR hangs. That's a minimum compliment for anything close to hard rock, ear-splitting Indian or other Asian program, and most African genres.

Your subs will also be inadequate. Evan K's estimation is pretty much spot on.

Good luck. You'll need it.

Tim Mc
 
Re: Advice on JBL VERTEC 4887

Tim McCulloch said:
No.

We own both 4887 and 4889, and for arena work up to 12,000 or so we take 12 4889 per side and 8 4887 per side for the LL/RR hangs. That's a minimum compliment for anything close to hard rock, ear-splitting Indian or other Asian program, and most African genres.

Your subs will also be inadequate. Evan K's estimation is pretty much spot on.

Good luck. You'll need it.

Tim Mc
Click to expand...

Thanks all for your help, I guess we will consider buying the 4889 and more units .
What is the maximum amount of crowd that the 4887 can handle in open area (live band of rock pop etc...) ?
 
Re: Advice on JBL VERTEC 4887

Idan Pi said:
Thanks all for your help, I guess we will consider buying the 4889 and more units .
What is the maximum amount of crowd that the 4887 can handle in open area (live band of rock pop etc...) ?
Click to expand...

1739 people. Give or take 2.

Seriously-there is no "number" for any system. It depends on how loud you are running it, how tightly packed the people are-how wide and how deep the audience is and so forth.

What is loud to some people is barely running for others.

You could take any "number" of people and go up or down quite a bit depending on the particular situation and system.
 
Re: Advice on JBL VERTEC 4887

I suggest you download JBL's Line Array Calculator II. One has to register for it, but it's free. You can define the size of your sound field, create some coverage and place virtual measurement mics in the sound field (similar to Meyer's MAPP, but not as detailed or extensive) and look at SPL/frequency at those locations.

Read the instruction PDF file. It goes into detail regarding the making of physical measurements and using the program to achieve the desired results.

Have fun, good luck.

Tim Mc
 
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