I wanted to understand more about the speaker watts, impedence, amplifier volts relationship.

After a quick reading I think I get the relationship. For Example

Lets take a Beomaster 4500 with Long-term max. output power IEC: 2 x 55 W / 8 ohms 

This means I can take for example any 8 ohms impedance speaker ( RL 60.2) and match it with the 4500 with no issues or may be the best match as the RL 60.2 can acutally take 75 Watts input by design

Question:

1. What happens if I connect the S45-2 to the beomaster 4500 which are rated at Continuous load: 56 W , Music load: 75 W ( 2. What is the difference here) and Impedance: 4 - 8 ohms

3. If you note the impedance range of S45-2 - does this mean the S45-2 is capable of getting upto 110 Watts if its at 4ohms impedence - I know the impedence is dynamic meaning the watts are too.

Can some one do a better job at this explanation or Do I have it right?

Thanks

With above post I am not trying to under play the complex relationship of a loudspeaker and amplifier. All I am trying for is a simpler understanding!

Thanks

I don't blame you for the confusion. One of the problems is the actual measurement of figures. Around the end of the eighties, B&O started measuring power using different parameters. This caused the Beomaster 5500 to go from being a 55W per channel amplifier to being a 110W per channel amplifier. Clearly nonsense but of no importance as it still sounded just the same! It did however throw the wattage ratings of speakers into disarray. The S45-2 can take anything the BM4500 can throw at it (except distortion!) as the BM4500 has about a 30W per channel amplifier using the old measurements on which the S45-2 is based.

However the whole thing is a little academic. Speakers will on the whole prefer a big amplifier developing lots of undistorted power to a small one struggling and hence distorting. My speakers at home recommend a 25W linit but I have used every B&O amplifier going with then right up to a BM8000. They were all fine. I doubt you will find a B&O speaker that the BM4500 will have a problem with.

On the impedance bit, these figures are on the whole not worth looking at. The impedance varies massively across the frequency spectrum. The S45-2 quotes 4-8 ohms but will vary far more than that. The perfect amplifier will produce more power into low impedances but in reality this will roll off pretty quickly; the Beolab 5000 service manual has a nice chart showing the effect of impedance on power output.

Does that means that if you apply the similar logic (beomaster 5500) the beomaster 4500 watt out put would also double from 55 to 110?

How could a change in standard of that drastic impact on watts would or was accepted? 

if you connect two 8 ohm speakers together (not in series) they in effect become a 4 ohm speaker

Two 6 ohm speakers toghether will become a 3 ohm speaker.

sodoi18:

Does that means that if you apply the similar logic (beomaster 5500) the beomaster 4500 watt out put would also double from 55 to 110?

How could a change in standard of that drastic impact on watts would or was accepted? 

The 4500 is also measured by the "new" standard (RMS?), it is producing 30 watts, just like the 5500 is producing 55 watts in the older standard.

sodoi18:

Does that means that if you apply the similar logic (beomaster 5500) the beomaster 4500 watt out put would also double from 55 to 110?

How could a change in standard of that drastic impact on watts would or was accepted? 

No, the 4500 doubled from 30 to 55!!! It all depends on the method of measurement. B&O simply fell into line with others. Power is mainly a marketing device anyway! Very debatable how important a few watts one way or another is - we tend to use about 1W when listening normally!

Thanks all

Since we are talking about watts - Is MCL2P now a 60 Watts instead of 30 Watts?

Also if you add a 2nd pair of speakers do you halve the amount of 'power' that goes to each set?

Large48:

Also if you add a 2nd pair of speakers do you halve the amount of 'power' that goes to each set?

That is right, and if you connect in parralel, just like on a normal amplifer, the impendance will be half of the speakers'

sodoi18:

Since we are talking about watts - Is MCL2P now a 60 Watts instead of 30 Watts?

The MCL2P amplifier is much the same as a BM4500 - so yes!