I think the kemper powerhead at full volume is to much for one speakers.probably the sound peaks damage my two speakers.now i turn the power amp boost to higher settings,and all is ok¡¡¡
??? Did you read the post from CK just 3 posts above yours?
By using Power Amp Boost your speakers are even more in danger - it's just a simple 'power boost' no compression/limiter or whatever involved.
The NEXT sentence in the manual seems to also be important. If it is accurate, a limiter comes after the Booster, but is not part of it.
"Very loud signals and transients will then be compressed by a nice, organic-sounding soft-clipping circuit."
So, The Power Amp Booster is a simple volume control. But, turn it up, and transients will be compressed by a separate circuit. That's why a setting of +10 can protect a V30 or two.
Ups - yes, that's the oposite what most uers expect - if Power Amp Boost is used the speaker is even more in danger to be damaged!
Hmm - that is exactly what I would expect and want from a booster first and foremost: a volume increase.
I'm glad I decided on the un-powered version......this is making my head hurt 
I'm glad I decided on the un-powered version......this is making my head hurt
Ha-ha, yep me too 
Hmm - that is exactly what I would expect and want from a booster first and foremost: a volume increase.
Yes, sure - but some users got the impression that the KPA protects the speaker in case this booster is used.
Currently do I understant it - according to the manual - that the monitor output will be send to:
a) a simple booster (without additional compression/limiter)
b) a soft clipping compressor (allways on)
c) the very powerfull 600Watt class D amp (allways max output)
all this can easily blow your 25/50 or even 200Watt guitar speaker.
In case the booster is used - then this can happen even more likely.
So if you use a 4x12 with 200Watt EV speakers - don't worry - if you use a lower power cabinet - do not increase the volume to much.
IMHO would the best solution to get some power settings - say 20/50/100/max Watt.
I think you should not worry too much.
We didi many tests at very high volumes, and never broke a speaker.
We have recently done tests for the 4 Ohm behaviour at insane volumes. Nothing broke.
Up to now we are aware of only a handfull of cases where speaker broke, often even at moderate volumes.
I must assume that the speaker had a weak point. That happens even with tube amps.
About wattage: High wattage is a shy animal, as it has a quadratic relation to the volume.
When you turn down the volume by 6 dB, you bring the Watts down to a quarter!
Yes, or in other words - we need ten times more power to double the loudness.
btw - here is something to read about different amp types (class a, ab d, ...):
http://www.soundonsound.com/so…articles/loudandlight.htm
I have a power head. I have a 2x12 8 ohm 150 W with zero issues. I ran a 1x12 65w 8 ohm, zero issues. Simply stated, I think it is one of two issues with the original poster. A defective power supply or defective wiring of cabinet. Based on what he described it is not normal to blow speakers. There is more to this than a simple blown speaker(s).
I'm glad I decided on the un-powered version......this is making my head hurt
Well, with Great Power comes Great Responsibility!
Well, with Great Power comes Great Responsibility!
LOL 
Well, with Great Power comes Great Responsibility!
Again, a 600Watt class D amp can kill a 100Watt speaker - as well as a 100Watt tube amp can kill a 15Watt guitar speaker.
Again, a 600Watt class D amp can kill a 100Watt speaker - as well as a 100Watt tube amp can kill a 15Watt guitar speaker.
Can we have the secure ratio? How many speaker-Watt do we really need?
Because, a guitar cab with 600W is not very easy to find (except Marshall full stack ...)
It would help if we have a orientation table (e.g. power boost 0 db, master 5 = 60W speaker, power boost 3db, master 5 = 120W ...)
I really LOVE to play Kemper Powerhead through guitar speaker, that is how I use it all the time (live additionally Main-out-to-FOH).
In the last 6 months I have used it with 4x12 (8 Ohm, 300W), 2x12 (8 Ohm and 16 Ohm, 140W), 1x12 (16 Ohm, 60W) with Power Boost at 3-4 db and Master at max. 6 without any problems.
I read in some thread where a Kemper official said they are planning some kind of power metering or scaling in the software. Don't ask me where I read it but it was in these forums.
i think the boost reduces peaks of sounds.but no,is a other volumen knob(more volume)
Well, let's see it this way: when cranked, the boost reduces the relative peaks (peak value minus average value) due to the limited nature of any electric device, but not the absolute peak (peak voltage).
I read in some thread where a Kemper official said they are planning some kind of power metering or scaling in the software. Don't ask me where I read it but it was in these forums.
I can confirm that. As far as I remember CK stated it when somebody had Problems with a powered Kemper and 4 Ohm guitar box.
