What tube amp for Harbeth 40.1

I watch that video, it is interesting.  But I have a question.  Is it really the speaker drawing power?  I don’t think the speakers draw power, but it is the amp pushing power, right?  
I have a question. if we play the same music, volume knob at the same level, to a more sensitive speaker, will it display that it is pushing the same 750W power?  Of course, the music will be louder pushing the same amount of power to a more sensitive speaker.

On the other hand, What if using an amp with smaller power playing the same song, how will that look like ...

https://www.psaudio.com/askpaul/do-amplifiers-push-or-pull-power/

I actually thought this would be more useful. But its semantics. 

@gte357s ,

’I don’t think the speakers draw power, but it is the amp pushing power, right?’


The speaker / amp relationship is pretty murky, at least to me, but the important thing to remember is that to get the same volume from the M40s a lesser powered amp might be forced into clipping, even if it’s for mere milliseconds.

Clipping happens when an amplifier runs out of power a bit like a car with a tiny engine going up a very steep hill. If there isn’t any protection built in to the amp, clipping can be disastrous for the loudspeaker.

With a more sensitive loudspeaker you certainly wouldn’t want to keep the volume knob in the same position unless you wanted to use it outdoors or in a much larger room.

This is assuming that it was capable of being played much louder in the first place. Not all more sensitive speakers are, but size is a good indicator.

It’s also worth remembering that loudspeakers are horribly inefficient devices. Hence the temperatures inside the voice coil can reach hundreds of degrees.

Much like car engines, most of the power going in is converted into heat. not sound (or in the case of the car engine, power). Overheating is a common enemy of both.

For those who like to play loud, thankfully before we are able to destroy our speakers by overheating, we should get a warning by experiencing a compression (and likely much distortion) in the sound.

It might simply not be worth going beyond a certain point of the amp volume dial as the speaker will tend to only get hotter, not louder.

https://en.m.wikipedia.org/wiki/Power_compression

I stream a Cambridge Edge NQ through balanced cables to a McIntosh 275 into Harbeth 7-ES3 speakers and I am extremely happy with the result, as I age, my hearing has deteriorated so I can't analyse the result except to say it is the best music I have enjoyed in 50 years of Hi Fi / audio experience

Try some Manley💪