Subjective Loudspeaker Testing Page 2

Now, let's seat them both in a living room and play them a perfect reproduction of the same performance. If the reproducer delivers to their ears exactly the same pattern of air vibrations that reached them in the concert hall, each listener will perceive an exact replica of the original sound. Each can choose to "tune in" to whatever aspects of the sound he normally listens to, and as long as they are delivered to his ears in exactly the same proportions as they were originally, the sound, to each listener, will be a perfect reproduction.

Now, suppose the reproducer is not perfect. (We're still looking for one that is.) Suppose it reproduces all of the information needed to hear the main themes and the rhythm, like a typical cheap phonograph, but tends to change harmonic structures and textures. Listener B, if he has had no practice whatsoever in analytical listening to reproduced sound, may notice that it is not a perfect reproduction, but he will find it pleasing because it gives him what he wants. Listener A, on the other hand, won't like the sound one little bit, even though he may not (through the same lack of listener training) be able to explain why he doesn't like it.

The fact that every loudspeaker is an imperfect reproducer of at least some aspects of a total sound is what accounts for the tremendous diversity of opinions as to what constitutes "the best" loudspeaker. Different listeners judge reproduced sound according to different criteria, and assign different "weights" to the various aspects of the sound.

This is why The Stereophile attempts, as much as possible, to describe the sound of loudspeakers that we test, as well as simply passing opinion judgments on them. This way, a reader who has found that he does not generally agree with our opinions may still be able to tell with some degree of certainty whether he will like a particular loudspeaker.

He may, for example, have learned that he prefers some forwardness to a neutral or distant perspective, that he values full, fat bass more than bass detail, and that his hearing limitations at the high end may make it immaterial whether the system extends to 18kHz or rolls off above 12kHz.

Component Considerations
In order for a test report to have any real validity, it must attempt to assess a component's inherent capabilities, rather than how it will sound with an amplifier or an acoustical environment that booms up the bass or rolls off the highs. Thus, all speakers, from the cheapest to the costliest, should be evaluated on the basis of their performance under ideal conditions—with the best possible associated equipment and in an essentially neutral acoustical environment. Then, when an amplifier or pickup is subsequently tested, and is described as having certain colorations (as heard through a top-grade speaker), the reader can get some idea as to whether the components in question will complement one another or aggravate one another's colorations.

Of course, components that are designed specifically for one another, like the Marantz turntable and pickup, must be reported as a unit. But as long as most components are sold as "universal" items, intended for use with a wide variety of associated components, they should be evaluated as such.

It is easy enough to sweep an oscillator through a loudspeaker's range and listen for peaks, dips, rattles and rolloffs, or to listen to some recordings and say this sounds distant or that sounds bass-heavy, but how does one divorce these attributes from the acoustical characteristics of the listening room, the normally wide variations in response and perspective from one recording to another, and the effects of individual preamps and power amplifiers on the sound of a loudspeaker?

Preamp influences are easily coped with. Since we have yet to find a preamplifier that does not have at least some audible effect on the signal, we do not use any preamp at all for most of our loudspeaker testing. Only power amps are used, driven directly from the outputs of a professional-type Ampex 2-track stereo recorder. The only controls in the circuit are the playback volume controls on the tape recorder.

The choice of a standard power amplifier was a bit more difficult. We had found, through many years of testing amplifier/speaker combinations of all varieties, that certain breeds of amplifiers—now represented by the Marantz 8B and Dynaco Stereo 70, to mention two—tended to elicit cleaner, more musical sound from most loudspeakers than any others, and yielded the best sound from those speakers which were theoretically closest to perfection. We adopted the Stereo 70 because, despite its much lower price, its sound is virtually identical to that of the Marantz (footnote 2).

The Listening Room
The main listening room—always an unpredictable factor in loudspeaker performance, was "chosen" to the extent that the last time Ye Editor was house hunting, he located a residence whose living room was close to the ideal proportions of 1 to 1.25 to 1.6, and whose longest dimension (18 feet) would support lows down to at least 30Hz. From that point on, the problem was to find out what the room's acoustical properties, after furnishing, did to the sound, to make necessary corrections wherever possible, and to make notes of the uncorrectable things so they wouldn't unduly influence future listening tests.

Then there was the period of adjustment, during which we "lived with" different speaker systems over a period of time, and carted them around to the homes of other audio hobbyists in the area to get an idea of how the bass performance in our standard listening room compared with that in other, typical rooms. Midrange and high-end evaluation of the standard room was effected by listening to the speakers outdoors, where they were unaffected by room acoustics, and comparing their outdoor colorations with the ones heard indoors. We found that the room tended to be a bit heavy in the 40Hz bass range, slightly depressed in the "presence" range, and almost perfectly neutral at the high end. These factors are now taken into consideration when testing loudspeakers. When in doubt, speakers are still checked outdoors and in other rooms, but we have found it possible to obtain a fairly consistently accurate impression of the performance of most systems within the confines of the standard room.

Choice of Music
Program material for the tests is derived mainly from two-track stereo tapes. Most of these are tapes we recorded ourselves, for these (despite some flaws in mike technique, hall acoustics and so on) are known quantities. We know the mikes that were used, the mike setup, and the hall acoustics, and we know the capabilities (and the state of adjustment) of the equipment used to record and play back the tapes. We also occasionally find commercial discs that prove to be dependable sources of wide-range, naturally balanced and natural-timbre material, and excerpts from some of these have been taped for testing purposes. (Again, occasional checks are made to ascertain that what we're getting from the tapes of these sounds like the originals.)

Summing Up
This whole setup may seem to some observers like the "tower of science" that was depicted some years ago in a Life magazine article—an inverted-pyramid-like, top-heavy structure erected upon a single toothpick, which was labeled "Basic Premise." We can't argue with this. All we can say in support of our structure is that it yields test reports that most of our readers have found trustworthy in terms of their own observations of the units we test.


Footnote 2: More recently, we have observed that the bass performance of a given loudspeaker is often markedly improved when it is driven by a good transistor amplifier, so until such time as the last top-notch tube amplifier becomes a thing of the past, we will be reporting on loudspeaker performance using two basic criteria: tube operation and transistor operation.
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COMMENTS
Glotz's picture

lol.. Sorry, I'm a sucker for cheap jokes.

Poor Audiophile's picture

Sorry what?
Wait. Are you talking about the attractive young woman? It is an odd picture!

Ortofan's picture

... evaluated speakers by listening to them outdoors?

Poor Audiophile's picture

Great question!!

Bogolu Haranath's picture

When they want to evaluate outdoor weather-proof speakers :-) .......

johnnythunder's picture

they were specifically speakers made for outdoor use ? What is your point? What are you smoking? Why, after all the genius, brilliant points JGH makes do you arrive at the comment you made? What relevance does it have besides your own inherent continual naysaying and trolling on this site? Why don't you admit that you always knock a Stereophile reviewer's comments with some nonsensical and worthless post about a random measurement or the fact that the expensive component being reviewed is an automatic rip off compared to the budget component that you think measures better and therefore must SOUND better? Why do you read Stereophile if you continually disagree with the subjective based evaluation methods (brilliantly stated by JGH btw) that Stereophile uses to this day?

Ortofan's picture

... expensive versus "budget" components until you've read HR's review and seen JA1's measurements of the $1,200/pr Wharfedale Linton Heritage speakers. Then the question will be why can't other companies produce speakers that sound as good and measure as well for a similarly reasonable price?

johnnythunder's picture

My issue has been your knee jerk reaction without auditioning or listening to a component, that an "expensive" component that you don't feel measures perfectly or is somehow flawed in an engineering sense, is a rip off compared to something inexpensive that measures well. It's as simple as that. I don't believe in expensive meaning better by any stretch. I believe that we all have priorities in what we like about a component. I will listen and do a little research. I have purchased great sounding components that do not measure well and I don't care. I am also of the economic stature that the most I've spent on any one component is $2500. And I also want something to look nice too. You pay for more elevated product design and better materials for construction. SOmetimes that correlates to better sound sometimes just looking better and sophisticated.

Ortofan's picture

... are considered to sound great but do not measure well will explain why the two outcomes, for them, seem to be mutually exclusive.

johnnythunder's picture

The same components in a different designer's hands will sound different based on that "X factor" of little adjustments here and there that add up to something special on one hand or blah on the other hand. I work in a creative field - photography to be specific. You can give two photographers the same cameras and lighting diagrams and subjects and their results would be substantially different because one photographer has more charisma, soul, feeling and that stuff is more important to the finished product than the technical. It happens all the time. Countless times. Art - and I think the creation of many of the bespoke audiophile products we read about here count as ARTISTIC musical communication devices - is not that easy to make. Some of the designers of these products have more SOUL than others and care about different things in the creation of these components. Some WANT absolute clarity and some want the warmth of a Guarneri. To each their own. No measurement outside of ones that would designate a component as severely flawed and dangerous, should matter over a careful audition to find out if the component being considered speaks to you, makes you feel and hear the music more deeply.

Ortofan's picture

... whether or not you want your components to be imposing any amount of extra "clarity" or "warmth" upon all of the sound signals that pass through them, or do you want to hear the closest approximation to what the particular composer, performing artist(s), producer, and recording and mastering technicians intended for you to hear?

Bogolu Haranath's picture

Do you mean, you don't want any 'useful additive distortions (a.k.a. UAD)'? :-) .........

johnnythunder's picture

that I prefer a small amount of tube based warmth in my sounds. Many of my favorite engineered and reissued favorite recordings were recorded and remastered with analog equipment. I think "accurate and 100% truthful to the source" or "the engineers intentions" are bars that are nearly impossible to live up to at home with a fairly modestly based system. Too many variables and too many choices to make. Only at "Michael Fremer levels of system expenditures" do I feel you can get a system that is that perfect mix of detail and body ( and I think MF's preferences are towards extraction of detail and transient detail and clarity rather than warmth.) Nor do I really feel that I'm insulting anyone by not listening to something exactly precisely the way it was intended (I watch way too many classic movies on bluray to worry about that - the directors largely shot on 35mm or 65mm film and expected their films to be experienced in a theatre projected that way.) I'm not in favor of gross distortions (I haven't owned an amp with tone controls in 30 years) but just as I like my TV color w very rich black levels I prefer my audio sounds a little warm rather than lean. Poorly recorded pop or classical from the early days of digital - tinny and harsh and thin - sound much better TO ME with the added warmth I get from the tubes and other peripherals in my system. I'm not saying its correct or that everyone else needs to enjoy it that way. It is what I like and prefer and that's all that matters.

Ortofan's picture

... tube buffer stage devices from either iFi or Icon?
https://ifi-audio.com/products/micro-itube2/
https://iconaudio.com/all-valve-buffer-amplifier-ba3

Bogolu Haranath's picture

FWIW ..... JGH does mention about outdoor listening :-) ........

Bogolu Haranath's picture

Wonder whether Wilson Audio listened to their WAMM speakers outdoors and then moved them inside for final tuning? ...... That would qualify the WAMM speakers as "tower of science" :-) ........

jimtavegia's picture

will not work unless you intend to listen outside. You should evaluate everything where you intend to use it.

Ortofan's picture

... shouldn't ever be measured in an anechoic chamber.

jimtavegia's picture

I guess that kind of testing will work for you. The reality is that we want amps that measure flat and speakers that can do close to the same (although none do) so we can make adjustments in our rooms if we choose, but I doubt most people do not. This is why speakers are always the weakest link, especially their cabinet resonances. Matching speakers to room will always be the hardest thing to do.

Glotz's picture

She seems a bit off-kilter in her listening position... like she's either in pain holding that lp or she is quite... dead.

volvic's picture

That is one of my back exercises that I do while listening, only difference is that the record is on the turntable and not in my hands.

Bogolu Haranath's picture

She is listening to 'Love Me Tender' now ........ She wants to listen to 'Martha My Dear' next on the album in her hands :-) ........

Bogolu Haranath's picture

May be she is listening to in-ceiling speakers? ........ That console may be just playback gear? :-) .......

Bogolu Haranath's picture

Fast forward to 2020 ...... She could be listening to Bluetooth in-ear phones and texting on the smart-phone :-) ........

Bogolu Haranath's picture

Loudspeakers and their drivers design and engineering are far more advanced now than, they were in the 60s and 70s ....... Thiele-Small parameters were first published in the late 60s and early 70s for example :-) .......

ok's picture

is that they prompt you to read present articles as historical ones.

Glotz's picture

A Matter of Taste

Suppose we take two listeners, whom we shall call A and B, to a live performance of the Eroica symphony. If they sit side by side, both listeners will be exposed to essentially the same set of sound waves, but listener A may concentrate on the pattern of harmonies and instrumental textures, while listener B may be "tuned in" to the main themes and the rhythmic groupings. Each is hearing the entire complex of sound, in the sense that his eardrums and nervous system are responding to it, but each is perceiving—that is, is consciously aware of—different aspects of the sound.

Read more at https://www.stereophile.com/content/subjective-loudspeaker-testing#0yOF1tMqrEqD5jEl.99

Huh.

BDP24's picture

...is stated by JGH in his text. He moved a set of loudspeakers outside in order to determine how the room acoustics affected the sound of the speaker, so that he could then "subtract" that room sound from the sound produced by any and all other loudspeakers in that room. Sound heard from a loudspeaker in his room = 3. The sound of the room itself = 1. The actual sound of that speaker (as would be heard outside or in an anechoic chamber) = 2 (3 - 1).

Bogolu Haranath's picture

Listening to loudspeakers outdoors can almost mimic an anechoic chamber testing, because of the distances of the reflective surfaces are usually far greater than most of the room boundaries ......... Hence, less influence of the room boundaries reflected sound ........ JA1 tests some speakers outdoors, if possible to move them outdoors :-) .......

When this article was written, JGH most likely did not have the modern day testing equipment and computer software programs :-) .......

Of course, the design and tonal balance of outdoor speakers is different from speakers designed for indoor use :-) .........

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