Re: JBL SRX / QSC PL236 underpowered?
Hello Andrew, back to the math, maybe this will shed different light on the subject...
As a reference 800W is 10A and 80V into 8 ohms, this can be your continuous spec from JBL
Now for program, suggested is 1600W, which is 14A and 113V into 8 ohms, this equates to 1.414 x the 80V reference voltage, not much - SPLwize the +3db difference is barely noticiable to the average listener. So you are not really gaining anything here.
Peak wattage - which is defined as the max you should momentarially apply to the system is 3200W or 20A and 160V - not many amps can provide this for more than a few tens of milliseconds (thank goodness) This is 2X our 80V voltage and is +6db. You can hear this increase. But you can get the same +6db by coupling cabinets together (mostly low freq) if you drive them with the same power (current x voltage).. You can not run this power into the speakers except for milliseconds.
Most live program has a very wide dynamic range, +16db or more easily. it is difficult for a live PA system to amplifiy that range without compromises. Think about the +6db SPL gain you get with 4X the power, add the cost of amps and cost of power infrastructure to the equation, and thats why a PA is designed around the app. You could use the biggest amps you can find and most effecient speakers designed to handle all scenerios, but it will most likely cost you a lot.
Mike
