escapemcp wrote:
Yeah, I have seen that but I have 2 issues with it:
1) It's Behringer's specs, which we all know are a little off
2) Because power is a function of time, if they have measured the power over a minute, or even a few seconds, you never get the INSTANTANEOUS power figure (which is what will stall or trip my genny - especially if it is an inverter one as they have no heavy flywheel for power storage through inertia of the wheel). This is just like the RMS/Program/Peak values that we all see on speakers and amps. A 1000W amp with 6dB headroom can supply a 4000W peak (yes?), but is still a 1K amp, as that is what it can deliver CONTINUOUSLY. Now Behringer may say 210W consumption @ 4 ohms, but that means little (it is also (most probably), continuous). It's like trying to work out the top speed that I went on a particular journey only based on my average speed.
Have read through the plans (thanks for quick turnaround Bill)... now, time to start again and re-read!
Arr see, now you have to read fully.
Switch mode power supplies cycle faster to keep power up to the rails, and since that's what Class D amps have as a generalisation:
It tells you in those specs what the fuse rating is, dependent on country model.
It's not about the maximum power your amp can output as transients, it's about the most power it can consume (before the fuse will blow) to produce that output
So if you have eg 240V power, the fuse is rated @ 6.3 amps. If the fuse does it's job, that means it will blow after or around 6.3 amps. Which means that maximum required power from your power source would be 1512W or thereabouts.
Given that, you would think that, with a little overhead a 2.5Kv genny (or inverter) should be ample.
I imagine you would be well into hard clipping if you were running the amp to a level that was making fuses blow, much less any inbuilt protection circuitry.
You're correct though, you do need enough power for instantaneous requirement. We can't run a small stick welder or a medium sized compressor on our (old) 2.5Kv genny on the farm. Most noticeably the compressor, where all the load is trying to get that motor to turn the piston over that very first time.
We can hear the motor on the genny bogging down with an electric drill or an angle grinder.
All these things though are motor driven tools, and I'm sure that a switch mode power supply isn't quite so demanding...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...
The article where I saw these figures is http://forum.speakerplans.com/behringer ... 69202.html. The 24A figure (mentioned toward bottom of 1st page in the section when he's testing the 4ohm output) was when amping a sine wave at full power, so I suppose it is not 'real world', but I don't want to be worrying every time a heavy bass line hits 
Bill, I have just sent money in your general direction!! Looking forward to receiving the plans 
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things like rip cut and negative rake mentioned. I assume that rip cut is cutting across the grain (but with ply, I am ALWAYS cutting across the grain or either plys 2 & 4 or 1, 3 & 5!). How many teeth?
