As the amplifiers are build-in in the beolab range loudspeakers, how to interpret the (high) watt counts if you want to compare them with the traditional amplifiers? (measured in RMS)  For instance beolab 9 -> 700 Watt?? Beolab 5 -> 2500 watt.. 

They are rms numbers.

 

100W beo is 100W of whatever other make that measures continuing power output. The secret is the ICE power D-class amps.

 

I asked a question about this not long ago, about the Lab 5's . Search on Beolab 5 and you will find the thread. 

Tricky! The power outputs are claimed as long term power outputs. In my experience, halving them makes more sensible reading! However in the case of ICE power, this is probably unfairly underestimating the sound output. The modules in the pre-ICE power Beolab 4000 were rated as 59W and the ICE power ones as 30W. The sound pressure for the speakers are unchanged.

RMS (root mean squared) is more of a marketing thing than a truly useful measurement. What you're looking for is the long-term output (which isn't RMS). BeoLab 5s are rated at 2500 watts long term output, which is a figure I actually believe they can deliver. On the other hand, the Panasonic 3.1 system I was listening to earlier was rated at 1000 watts, which I can't believe for one second!

The truth of the matter is, there are a million and one ways of measuring the wattage output of different amplifiers. Some companies measure the input power to the amplifier, which is much less than the output power, wheras others measure the peak output for a fraction of a second. Sometimes peak output can be measured for a good half a second. The most useful measurements are the continuous measurements, which is what B&O supplies with the BeoLab 5s. Not sure about the BeoLab 9, don't have the service manual to hand.

RMS may have been marketing, but it was a fairly standard measure and allowed comparison. Today's free for all is far more hype and B&O are not wholly innocent!

Peter: 

When has the amp for the Beolab 4000 changed?

 I just checked B&O website, and it still says A/B 59W. Shouldn't B&O be up to date with these things...?

 

Last year! You can tell them easily as the on off switch has gone from the front. It is now just a light!

Peter :

Last year! You can tell them easily as the on off switch has gone from the front. It is now just a light!

 

B&O seems very slow updating the website then... A firm their size portraying a image of quality and finesse, should get their product information sorted. 

They didn't bother to change the facts in the 2008 swedish version of their catalogue either.