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Define accuracy

You can design an amplifier or electronic component to a given specification. To specific design criterion.

You can design a speaker to a given specification. To specific design criterion. Speakers are the most interesting case when it comes to "objective" measurements. We see some measurements in some speaker reviews. Amplitude response and electrical phase (seldom ACOUSTICAL phase, which is amplitude response and acoustical phase, or the two components of 'frequency response'). We may even see impulse or step response.

But do we ever see polar response? Two speakers measured on-axis may have similar on-axis response but radically different off-axis response due to driver interaction and crossover topology.

So you take two speakers that measure "similarly" on-axis which are not the same at all and put them in two different rooms with different floor, wall and ceiling materials, and different distances from walls to speakers, between speakers and to the listener. Add to that different toe-in angles.

You're going to get pretty much an INFINATE combination of different products, unless audio rooms are built to a specification, with materials, distances and equipment all specified (as is done with some theatres built to a specification.)

What does this all mean?

Even if "objective measurements" have a place in making a product meet design criterion and topology, they have far less use for the audiophile purchasing gear. This is because he has all these other variables at play which will affect how "bright" the speaker will sound (tonal balance, etc.) and how the speaker will present the holographic "effect" we call image:

a) room size and height
b) room materials including floor coverings, window coverings, treatments
c) speaker and chair placement
d) speaker distance from back and side walls, from eachother and from the chair
e) speaker toe-in
f) the most important factor of ALL: the individual recording

When you're mucking about with a though f, suddenly these VERY "telltale" objective measurements from specifications and review tests become rough guides at best. I've heard speakers that were nice in one place moved to their new home where the person was suddenly less impressed. Sure. Is there any question as to why?

You can try to write a nice long rant about why subjectivist audiophiles are inept and in denial, and you can go on about the ability of sound waves to be measured in 12 different ways. Measuring ability is not even close to being the final "point" - it's what data we would collect and how we would INTERPRET these data sets.

For one thing, we could go a LOT further to explain why different system/room/placement/toe-in combinations sound and image differently even with the SAME speakers. Polar response of a given set of speakers is constant - each speaker has the same polar response. But how this response interacts with the OTHER speaker AND room boundaries to create a specific image "EFFECT" will vary for pretty much all system/room/placement/toe-in combinations. And this CAN be measured. But do we measure this way? Hardly.

The designer does on-axis measurements. Maybe he considers off-axis response and power response. Maybe he considers the kinds of rooms that his speakers MIGHT go into. Who knows what kind of room he's voicing his speakers in...

In any case, with the wide varieties in speakers (with their unique on and off-axis response and voicing) rooms, treatments, placement and on top of ALL of that, 10 different recording engineers capturing the same acoustic event 10 different ways, each with a unique process and equipment from the mix to the final mastering...

You bet it's subjective.

If you can write a book about ALL of the things we can measure that help mould the final sound we hear sitting in a chair, congratulations. It will 1000 pages of stuff we probably already knew, and none of it will change anything about the way we record and mix and master music, and none of it will have any relevance to an audiophile who knows that the final "proof" is in his subjective and qualitative assessment of his own music on his own system in his own house in his own mood with his own ears and his own biases and preconceptions.

Until you can take the human brain out of the "chain" (it's always the final frontier of sound reproduction) all the measurements in the world will not result in the "single correct system" that is based on "all the right and relevant measurements".

Cheers,
Presto

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