Compact 7 with 8.5W AudioNote 300B Kit 1

[jazzman]

Hi,

I'm new to this forum and am considering getting the Compact 7. I will however be running it with a 8.5W AudioNote Kit1 300B. I'm concerned about whether the Ki1 can drive the Compact 7 adequately.

Would dearly appreciate your advice and suggestions. Thank you.

[David Schalkwyk]

I don't have any specific suggestions, but I wonder what members of the forum (and Alan) think about Keith Howard's article in the October Hi-Fi News (the same one that includes the essay on Harbeth) on required power ratings for domestic amplifiers. Using B&W 'speakers rated at a sensitivity of 87.5 dB and fairly constant impedance load he concludes, from tests of high current and voltage requiremenst on a variety of different kinds of music, that a minimum of about 800W would be required if the amplifier were not to be forced into clipping. That is way beyond what, I suspect, 90% of us have. (I have a mere 16W, in Class A--does this make a difference?) It's what Michaelson of Music Fidelity has always been saying. Does this mean that we need to rethink completely our assumptions about amplifier power (and the size of our wallets)?

Cheers

David

[A.S.]

... he concludes, from tests of high current and voltage requirements on a variety of different kinds of music, that a minimum of about 800W would be required if the amplifier ...

This article does not seem to quote his in-room listening level (he refers to an earlier article) but he must have been listening extremely loud for those sorts of powers to be drawn from the amplifier - even for transients. The listening experience must have been painful - and potentially dangerous. Regarding Harbeth speakers, we here know from personal experience that as little as 5-10W is necessary to make beautiful music at home and that 100W or so provides a hugely loud sonic experience.

And now a vitally important point: Let's be quite clear about levels: anyone who has experienced a real, live concert knows that (even) orchestral music can be very loud. So loud that it would be both antisocial and dangerous for the hearing to fold the orchestra into the confined listening space of our normal living rooms. We are not kidding ourselves that we are actually, measurably, 'listening at concert hall sound pressures' at home - thank goodness!

What sets a Harbeth apart from conventional speakers is that the design is optimised for listening at home in our 4m x 3m room - similar in size to a BBC control room. Although the BBC engineers go to the other side of the glass where the orchestra playing much, much louder, the balance of a 'BBC monitor' is such that back in the control those speakers playing far below actual concert level sound natural and correctly balanced. A Harbeth is a bonsai tree is to the real thing: a perfect scaled-down rendition of the real thing complete in every detail. That is a very different design philosophy to conventional 'hi-fi' speakers which only seem to sound correctly balanced when hammered.

[David Schalkwyk]

Thanks, Alan. That puts things nicely into perspective. I was puzzled by the fact that if we need so much extra power, it hasn't been immediately apparent to all of us. So we ask that bug-bear of audiophile questions: what are we missing?

Your bonzai comparison is very useful. Bonzais are not exactly analogous to their bigger cousins, of course. Their leaves are always proportionally somewhat bigger, but that makes the comparions even more apt.

David

[A.S.]

Underpinning a Harbeth design is a particular set of design objectives which is not found in any other approach to speaker design. I am not saying - and would never say - that one particular approach leads to a speaker which is universally 'the best', regardless of listening level, musical taste, cost, styling or whatever. Hence, there are thousands of speakers available to the consumer.

But what our BBC pedigree contributes is a design approach which results in speaker designs which are essentially professional tools - capital equipment - presented in attractive consumer-friendly cabinets. It is no coincidence that a BBC control room is about the same size as a typical domestic listening space. It is also no coincidence that Harbeth has a considerable reputation in the Far East where listening spaces are, typically, small. Add to the philosophy argument the fact that the BBC is extremely cost-conscious (the best value for the taxpayers dollar) and you have the perfect package of engineering, performance and affordable durability. That's an extremely appealing package proposition for the Harbeth home user.

You could truly say that the BBC monitor philosophy is really 'at home', at home: the right design approach to give a life-like, warm, engaging sound in real, normal living rooms at a sensible and neighbour-friendly listening level. Again, it is no coincidence that as living spaces become ever smaller Harbeth's popularity rises.