I'm embarrassed to even ask this because I feel like I should know all of this stuff at this point in my career. I know much has been posted about how to properly set up limiters to protect speaker components, but I have to admit, I don't understand the math and terminology and frankly, I'm afraid of blowing up my speakers without proper settings. Is it inappropriate or too much to ask of someone in the know to help me with these settings?
I have a 16 box EAW KF730 rig run from 4 (total) Crest Pro9200 amps. The signal is processed through an Ashly Protea 4.24C. I built the system to match that of another guy in the area for the purpose of cross renting. Not much of that has happened in the last decade of ownership, and I would like to make some changes to my own system.
I've always loved the sound of the system but, while recognizing that it has limitations because it is a smaller array, I believe the system is underpowered. I have been running it as follows (per side):
Crest 1---Channel 1---KF730 Hi/Mid===2200 Watts @ 4 Ohms for 1400 Watt speakers (4 @ 350 Watts each @ 16 Ohms)
Crest 1---Channel 2---KF730 Hi/Mid===2200 Watts @ 4 Ohms for 1400 Watt speakers (4 @ 350 Watts each @ 16 Ohms)
Crest 2---Channel 1---KF730 Low===2200 Watts @ 4 Ohms for 2800 Watt speakers (4 @ 700 Watts each @ 16 Ohms)
Crest 2---Channel 2---KF730 Low===2200 Watts @ 4 Ohms for 2800 Watt speakers (4 @ 700 Watts each @ 16 Ohms)
Roughly going from the EAW general rule of using an amplifier capable of twice the rated speaker power, the Hi/Mid section seems to be great. The lows seem to be greatly lacking.
As a disclaimer, I'm not trying to make the arrays have more SPL as much as I'm just trying to get more headroom, instead of constantly operating at the limits of the amplifier for the entire show.
To set the limiters in the past, I have left the speakers disconnected from the amps and sent a signal through the processor, into the amps until the amps clipped. Back down the limiter until clip light goes out, done. I figure because the amps are the weakest link, that is my limit point.
My idea for more headroom is to keep the Hi/Mids as is and split the lows into two separate amps set to bridge-mono. The setup now looks like this:
Crest 1---Channel 1---KF730 Hi/Mid===2200 Watts @ 4 Ohms for 1400 Watt speakers (4 @ 350 Watts each @ 16 Ohms)
Crest 1---Channel 2---KF730 Hi/Mid===2200 Watts @ 4 Ohms for 1400 Watt speakers (4 @ 350 Watts each @ 16 Ohms)
Crest 2---Bridged---KF730 Low===6500 Watts @ 4 Ohms for 2800 Watt speakers (4 @ 700 Watts each @ 16 Ohms)
Crest 3---Bridged---KF730 Low===6500 Watts @ 4 Ohms for 2800 Watt speakers (4 @ 700 Watts each @ 16 Ohms)
Even doubling the available power (2800W x 2 = 5600W), I'm setting myself up for an amazing fireworks show if I don't keep things limited properly. This is why I am here asking for help.
I already backed off the processor output to the lows by 6dB to compensate for going to bridge mono, but where do I set the limiters on those outputs? I see a lot of input sensitivity/impedance numbers on the equations listed, but I don't know what all of that means.
Would someone be willing to help me figure this out before I repeat the great "Eight 15" Drivers Gone With a Single Tom Hit" of '02?
And not to take a mile from the inch you might give me, but I'm trying to figure the same out for subs:
Crown CE4K---Bridged---EAW LA400 Subs===2800 Watts @ 4 Ohms for 1000 Watt speakers (2 @ 500 Watts each @ 8 Ohms)
Thank you sincerely.
Joe
Ashly Protea 4.24C
http://www.ashly.com/products/protea-system-processors.phpEAW KF730
http://eaw.com/portfolio_page/kf730/Crest Pro 9200
http://www.peaveycommercialaudio.com/media/pdf/Pro200_specs.pdfCrown CE4000
http://www.crownaudio.com/media/pdf/legacy/127393.pdfEAW LA400
http://eaw.com/portfolio_page/la400/