@Floyd Toole
I’d be very curious about your answer to a question I asked in a thread I created a while back:
Do We Want All Speakers To Sound The Same?
It’s a question that obviously has more nuance than implied by that single sentence.
And if you’d like to answer the question you don’t have to visit that thread. You could just give it in this thread, please.
The general question arises from the idea of having a set of technical criteria for “accurate / good sound” in loudspeakers. For instance, the type of Harman Curve performance against which loudspeakers are generally evaluated by Amir.
If the idea is for any speaker to seek this performance, and measure extremely similarly, it suggests an end goal that is something like:
“All speakers will sound alike.”
And to a certain degree, it suggests that it would be ideal if this sound quality were commoditized. Which in a way would seem to deflate many of the directions currently taken by all sorts of manufacturers in high end audio. And in principle sort of suggests an abandonment of the type of “ bespoke” sound systems and sound characteristics currently sought by many audiophiles, where they select systems that represent their own vision of the sound they want.
It would be more like “ your system should sound pretty much exactly like my system.”
Again, there’s obviously tons of caveats and nuance - use cases, smaller versus larger speakers, SPL capability etc.
What would you prefer to see in an ideal outcome for sound reproduction especially in regard to speakers? And what room would you see for variations in performance? (Eg allowing for different preferences with regard to dispersion characteristics?)
Would this vision include room for omnis, dipole and bipoles, panel speakers, or any number of eccentric designs?
Cheers.
These are rational questions, given the history of loudspeakers.
Questions of that kind began with the first loudspeaker measurements I did in 1966. When I saw the very different and very messy anechoic curves from highly regarded loudspeakers, the first question in my mind was "why?". Even then all electronics aimed at a flat - neutral - frequency response. The best microphones aimed at a flat - neutral - frequency response. Why would loudspeakers not aim at the same target? After all, the purpose of sound
reproduction is to duplicate an original that existed somewhere. The "somewhere" can be a concert hall or a recording studio, and the product is "art" of infinite variety. The task of the audio playback hardware is to duplicate whatever the art is.
The first blind, loudness balanced, multiple-loudspeaker tests revealed that the loudspeakers sounded as bad as their measurements looked. It started my research.
This means that all
perfect audio products will sound the same - transparent, neutral
reproducers, lacking "personality". If consumers want to be distinctive, and it is a free world, that is where tone controls and equalization enter the picture. In spite of widespread folklore in the audio world - with the rarest of exceptions - that objective has been met in electronics or all kinds, wires, power cords, etc. It is a very mature technology, but in uncontrolled listening tests long essays continue to be written about the "easily audible" differences. Opinions trump facts. Twas ever so . . .
But loudspeakers have been more challenging. There are many more variables that matter to listeners, timbral and spatial, not all have been measured by most manufacturers, and not all of them can be controlled at the point of manufacture. The bass problems of listening rooms alone are enough to disrupt simple relationships between the loudspeaker product and the sound heard from it. Small rooms are large problems. Add in biasing influences of size, price, brand, reviews, internet chat and most consumers are not in a state of mind to be objective about what they hear in the normal "take it home and listen to it" sighted evaluations. Other factors complicate such evaluations, whether they are done by consumers or manufacturers. Few manufacturers over the years did, or cared about doing, double-blind evaluations - opinions reigned supreme, and recreational drugs are known to have been involved in some
. For some manufacturers loudspeakers became an extension of the art itself, but the problem with that notion is that all art is modified in the same way by the loudspeakers. Loudspeakers in the marketplace varied considerably in almost every respect, in part driven by the fact that listeners in stereo were not always rewarded by what they heard and sought all manner of tweaks to hear something that the two-channel delivery system was not capable of. That still is evident in these forum discussions.
Into this meandering scenario comes a story line from me and my colleagues, arguing that there are demonstrably reliable guidelines for loudspeaker design that yield relatively neutral loudspeakers. Understandably, not all manufacturers were pleased and opinionated subjective reviewers still bleat about how unfair science is. Routinely misunderstood, even in this current thread, is what we actually did - people don't read. The multiple-loudspeaker double-blind comparison tests revealed resonances, and identified loudspeakers with the least evidence of timbre corrupting resonances - an important beginning to
sound reproduction. The "trained" listeners were trained to recognize and identify resonances to convey this useful information to design engineers. They gave the same subjective ratings as untrained listeners with normal hearing, but did it much more quickly and more articulately. This is widely misunderstood. They were absolutely not trained to prefer a particular spectral balance - but, as physics shows, when resonances are absent, the frequency response is flat and smooth - as it has always been in all electronics.
It became clear to us early on that the low frequency problems in small rooms had to be attended to. At the very least, because small rooms exhibit characteristic "small room" resonance signatures. Unless these resonances are attenuated, timbres will be distorted and humans will recognize that they are listening in a small room, not the large spaces that are more desirable. We found very effective ways to do this and to deliver similar bass to multiple listeners, important for shared listening experiences. Not everybody bothers to do this, with predictably variable opinions resulting. So, the objective of "neutral" sound reproduction must include dealing with small room problems and they are all different - a "perfect" loudspeaker is not enough.
As for "omnis, dipole and bipoles, panel speakers, or any number of eccentric designs" these are all attempts to enhance the capabilities of stereo to address individual preferences. There is nothing distinctive in any of them that would make inherent resonances a desirable property - and our evidence from limited evaluations of these loudspeakers over the years is that they too need to be timbrally neutral, lending their "special" characteristics to the "soundstage and imaging" category of interrogation. In that category my investigations of many years ago - still not disproved - indicate that the recordings themselves are dominant factors.
In fact, when individual preferences, variations in recordings, and small room acoustics are considered, there would seem to be a continued need for tone controls and easily accessible equalization if critical listeners are to be satisfied. "Perfect" loudspeakers provide only a starting point, but it would seem, a rational one. When considered in isolation, they should sound very similar indeed - and they do. The best loudspeakers evaluated in double-blind subjective evaluations yield statistical ties - interacting differently with different recordings, but overall being judged superior to those with audible resonances. But the market needs products of many sizes, power handling capabilities, styles and prices to meet the needs of consumers. The reward for the scientific effort is that none of these variables restrict the delivery of essentially neutral sound quality as a starting point for consumer satisfaction, which can be identified in a comprehensive set of anechoic measurements - e.g. the spinorama. That alone is a major step forward.
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