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Hi
I figured this is kind of obscure and technical and I post this here in "propeller head" with that term used in the most flattering way.
I met Dick Heyser once a long time ago at a Synaudcon dinner and I felt so small I probably said 12 words total that night.
Dick Heyser was an inspiration for me and a few years later I was fortunate to work at a company that bought an early TEF machine (for measuring acoustic levitation transducers) which opened the world of Time/phase in loudspeakers for me.
Doug Jones was a friend of Dick's. After Dick's death, when Doug taught acoustics at Columbia college he felt his work had to be preserved and was the one who obtained and organized Dick's lab and writings, the archives. (link in this video).
I got to walk through his lab stuff and Doug and spent a good deal of time reading some of his work and pondering what he meant or did and I am still boggled by how far ahead he was and there are so many things i would ask him about things he said and maybe let him hear a speaker he described conceptually.
He really was a brilliant guy, A Ham, a physicist working at JPL who's hobby was hifi.
If you ever wondered about Dick, Doug gave a nice on-line presentation IF your on bookface :-)
I couldn't get my mic to work and ended up running out to the shop and grabbed a measurement mic and then had the level too low at first.
https://www.facebook.com/photo/?fbid=10225529512818801&set=gm.5792107924160098&idorvanity=1305077852863150
Tom Danley
Danley Sound Labs
Follow Ups:
Or at least a couple things important to Audio.
In his day, there were ways to measure Frequency response but time blind, there was no "phase response" AND if you set up a cost no object HP network analyzer, you could get phase if close enough but the speaker was buried in time delay related phase shift and reflected sound.
His TEF machine first captured "how far away is the speaker" at the highest frequencies (most precise) with the Energy vs Time Curve and then measured the magnitude with actual loudspeaker phase. Not just that but many measurements could be taken indoors now because of the Frequency windowing (much better noise immunity than time windowing)
With that, many things could be seen like the first waterfall displays, impulse response, step response, predictions of intelligibility and many other useful acoustic tools. It did not become the dominant technique because it was patented and narrowly licensed (like Beta tape was).
I even dragged an early TEF into the great Pyramid to measure the sound in the Kings chamber.
I can attest first hand to one way his discoveries went on to effect audio.
In the video "How we hear" i was asked about "hearing" and how we sense direction and distance.
https://www.facebook.com/watch/126113687424773/423500813293005
In the part describing the notches in your hearing, Doug Jones (in the original video i linked and was a friend of Dick's) was one of those people, he used the TEF machine to take those "in ear" measurements that discovered the last bits of "how we hear" direction and height. The LEDR recording Doug and co made used those notches to make objects move in the stereo image.
Those things i described about developing the speaker were actually following along an imaginary speaker Dick described late in life in one of the papers Doug had, a broad band single point in time and space.
With his TEF machine i was able to make one as he described theoretically in that video and has been the primary type of speaker we made.
The way i found was also one that had horn loading and the directivity of a large constant directivty horn.
How was also a question the video guy asked. See the "Expansion rate" video for a dry marker scribble.
Tom
In the first place speakers and every thing else sound different in different rooms so it's a logical fallacy to assume frequency response measurements of speakers mean very much, since those measurements are never consistent for different rooms. As I mentioned yesterday in another post on this thread some of the most important characteristics of sound cannot (rpt cannot) be measured. Examples: Air, transparency, richness, naturalness, soundstage dimensionality, coherence, presence, things of that nature.
So, this is the *big conundrum* for audiophiles, one that Dick Heyser was unaware. If we can't measure all the characteristics of sound where does that leave us? It leaves us having to get skilled at listening. This is the ONLY WAY FORWARD. In order to find the golden path to audio nirvana you have to be able to analyze what you hear and figure out what's wrong in the system and how to deal with it. Most audiophiles I reckon are at least two paradigm shifts behind the power curve.
Measurements can be useful when mapping out the room to determine ideal locations of speakers and locations for room acoustics treatments. But other than that measurements or specs serve little purpose or guidance for audiophiles how to proceed. There are a great many hurdles in thinking that must be overcome. As Bob Dylan says at the end of his records, good luck to everyone.
Not sure if you are musician but if you were a bass player and had a bass with a funny neck that had one or more dead spots or was missing the low E string, these flaws would be there regardless of what room you played it in. Listen to your loudspeakers outside (an excuse for a bbq) and you hear them without the room progressively containing the bass, so outside it's very thin but good stereo image, usually better than inside.
The emphasis on loudspeaker frequency response is that magnitude uniformity if possible at least at the source is ideal like flat response is elsewhere, an indicator of linearity, no dead notes.
The frequency response is what lets you distinguish a subwoofer from a portable radio before you recognize the song.
How it interacts with the room is effected by the speakers directivity, the more directive, the larger the "near field" area is where the direct sound is significantly louder than the reflected / late sound. The larger the room, the more difficult the room becomes to have a large nearfield. One could very rightly argue it's the response at the listening position, rather than 1m response that matters and that is more tied to directivity not 1m response.
Your descriptive vocabulary is that of reviewers "Air, transparency, richness, naturalness, soundstage dimensionality, coherence, presence, things of that nature." All describe the experience, the impression if you know the hifi terms, but the connection Heyser sought was between the hifi vocabulary of the day like you use and the engineering aspects of the loudspeaker. Remember those terms are mostly from for hire writers trying to capture / sell an impression .
Put your self on the other side off the product lifespan line.
The or at least one of the dilemma the speaker designer is in is that how do you make it sound the best regardless of what or who's music is played? What's the best anyway?
For me, the only blind indicator of anything like being "signal faithful" to any music was the generation loss test. With that you can hear what's wrong as it is exaggerated but it doesn't tell you what to fix.
I know people who's musical taste is shaped by what their speakers can do and that won't do here where i have no idea who will use them..
For speakers closer to the listeners. how do you also make them disappear in the stereo image, so that your not aware of the speakers and the singer is standing concretely sonic ally but invisibly in front of you more "real" than a center channel?
Those are some of the questions i have used Heyser's measurement system to investigate since our lab got one of the first ones in the late 80's
You are hyper focusing on frequency response again. Do you think I fell off a turnip truck yesterday? Regarding Heyser, as my boss at NASA would say, never get behind anyone 100 percent. I suspect trying to analyze speakers or any other audio component involves way to many variables to make generalizations regarding their performance.
Edits: 02/10/23
Hyper focused? Perhaps go back and read what i wrote and try to look at it from an engineering standpoint "as if" you were actually designing and building a new loudspeaker yourself.
How does one convert your reviewers descriptive / subjective vocabulary in to audible reality without real engineering?
Without knowledge of what does what in the design, your effectively left wondering where is the "talent" slider on the mixing board.
"Do you think I fell off a turnip truck yesterday"
Unclear exactly what you mean, are you suggesting a possible injury from a fall?
"Regarding Heyser, as my boss at NASA would say, never get behind anyone 100 percent."
While crediting a deceased audio pioneer isn't a parallel here in my book, two bits i heard making space flight hardware that apply "keep an open mind but not so much your brain falls out" and one that applies to politics as well, "the Vector of change, while less exciting is actually more important than the Magnitude of change".
This conversation can serve no purpose any more. It's a Mexican stand-off.
Yes perhaps, reminds me a little of a reactive circuit with Current and Voltage in that one has the real and imaginary components
More like trying to solve x number of simultaneous equations in x + n unknowns.
Edits: 02/11/23
~!
The Mind has No Firewall~ U.S. Army War College.
Nt
Edits: 02/10/23
~!
The Mind has No Firewall~ U.S. Army War College.
He was the first so far as i know, before his TDS invention, there was no way to measure the acoustic phase of a loudspeaker, his visual description was imaging a loudspeaker driver who's physical position changed moving forward and back depending on the phase and wavelength in question.
That paralleled the Beta tape vs VHS tape issue, Beta was better BUT was narrowly licensed while VHS was widely licensed.
Even now his TDS approach has much better noise immunity than the modern impulse based systems.
In the time domain, the wave launch and character of what we hear is Vast and changing, markedly influenced by our chosen listening environs . Your designs have consistently Been a logical progression in meeting the demands for, dare I say it? More realistic delivery of music. I never forgot the wave launch you created in that parking lot with the mono speaker. The recording soundly trumped anything I had heard in the past.... the astonishment augmented by the realization that I could perceive this whilst Not being THERE!
I have said what I wanted , was the midrange of a Quad ESl 63 , the highs of an ion tweeter and the horn bass of a Klipsch.... the wave launch of all these designs is different and no passive crossover is up to the task. I seriously doubt my active crossover with DSP can achieve what your approach has done.
The Mind has No Firewall~ U.S. Army War College.
The ESL-63's i am familiar with, in fact they had an impact on me at a time when i was making flat and curved electrostatic drivers. My Boss at Intersonics has 63's and asked me to "fix" them which meant by passing the protective spark gaps.
I said ok but cautioned that ALL of the ESS drivers i made eventually died sparking death in the quest of higher output (also his complaint and some months later so did his).
Having them home i listened to them in front of my home made ESS speakers and was struck by one unexpected aspect of their "sound".
At times it sounded like the origin of the sound was behind the panel and my conclusion was it was the effect of radiating much of the sound from a single point who's radius put the origin behind the rings of radiators caused by the delay network.
That radiation from a single point in time and space, creating the the radiation or as you say Launch of a single simple acoustic source and confined to a specific angle was the upshot of the original Unity horn and then the current Synergy horns.
I don't know how good an explanation it is but i was asked to explain that horn and some other stuff on the fly a while back. The "Expansion rate" video here goes into that.
Anyway, thanks for your kind words.
Tom
https://www.facebook.com/watch/126113687424773/423500813293005/
John Atkinson has striven to do that as well.
Maybe some day that dream will coalesce.
~!
The Mind has No Firewall~ U.S. Army War College.
more than one individual *have* gone down that theoretical path.
-!
The Mind has No Firewall~ U.S. Army War College.
Examples: Transparency, rhythm, truthfulness to the recording venue, immediacy, naturalness, realism, airiness, wetness, dryness, lushness, being congealed, completeness, soundstage dimensionality.You assume way too much. Even Heyser admitted he was puzzled by lack of correlation between what he heard and what he measured. Obviously some things are measurable. Like frequency response and SNR. Duh! Alas, he died too soon, I could have straightened him out. If only he could have hung on for another 15 years or so.
Edits: 02/08/23
~!
The Mind has No Firewall~ U.S. Army War College.
What things do you hear that can't be measured?
Edits: 02/13/23
I can describe a couple examples with loudspeakers, things like Heyser was after and what I have been working on for large scale sound..
You have two different speakers, they each have a very similar spectrum / frequency response and when you walk into the room with them playing one at a time, they sound similar. With your eyes closed playing one at a time standing in front of them, it is easy to point at each BUT with one type it was easy to guess/localize how far away it was, while the other was easy to point at but how far away it sounded depended on the recording.
In stereo, one pair virtually disappears within the phantom image, you may not even be aware of the speakers while the other pair presents a stereo image AND the right and left speakers stand out as part of the image.
Same situation, two pairs of speakers with very similar response but in stereo one pair present the mono phantom voice as a person standing in front of you, the other presents a wall of that persons image and everything else.
If you know what does these things, one can minimize them , to find the causes takes modifications, measurements and listening in a repeat as needed loop..
I come from future. I have some good news and bad news, mostly bad news for you. We found out quite some time ago having unused audio equipment in the sane room screws up the sound. That goes for speakers, cables, electronics, everything. Take it all out of the room immediately!
"Perhaps more than any other discipline, audio engineering involves not only purely objective characterization but also subjective interpretations. It is the listening experience, that personal and most private sensation, which is the intended result of our labors in audio engineering. No technical measurement, however glorified with mathematics, can escape that fact."
Nt
!
The Mind has No Firewall~ U.S. Army War College.
Free your mind from your self imposed reality tunnel and your ass will follow.
~!
The Mind has No Firewall~ U.S. Army War College.
Nt
George is even more colorful with that rainbow hair and all
Many AES long term members appear to have blinders on, I.e., "overly old school." AES is like a monument to objectivism. You could even say tombstone.1. Wire and cable directionality.
2. The effect of objects not related to the audio signal anywhere in the signal or acoustic waves in the room.
3. Audiophile fuses
4. Vibration isolation
5. Demagnetizing CDs
6. Cryogenic treatment of speaker assemblies, cables, CD players, etc.
7. The WA Quantum Chip
8. The Red X Pen
9. Silver Rainbow holographic Foil
Edits: 01/28/23 01/28/23
This is excellent, an ancient FM radio interview recording of Dick Heyser.
Listen for at least a little bit and you will get an idea what he was like and his passion for audio and what makes things tick.
The bone I was picking with "audio conservatives" like him, as I said before, with AES old school types is how blinded they often are to anything more than one sigma from the middle line, how awkward they are in the face of alien concepts.
Edits: 01/30/23
Hi
I only met him once and that was in company where i already felt too small to say much.
I can't say i understood much of what he said then either, I mean i understood most of the words but not enough to understand what he was talking about. That was the same for Dr Patronis at the table (turned out later he was a great guy and was a friend).
I can say being sort of a fan that Dick looked at things differently that those who only know "by the book". He was a Ham radio operator, those guys tend to tinker and get into how things work, he loved Hifi, wrote for Audio magazine, he worked at JPL and invented and made the gear that found a lot of the shuttle in the ocean. He invented the first measurement system that could measure a loudspeaker's anechoic response indoors and that was my involvement.
He saw measurements a little differently, in a cool way that was hard to grasp at first.
He said " we measure what we do because we can, not because they completely capture what we want to know" Think Total harmonic distortion, made sense in radio but not audio because there are so many variables in how much a harmonic stands out...or not at all.
He said Nature does not have units, we use time as a scale because we can divide it up neatly but it is not a universal scale. For instance any event at 20Hz takes 1000 times longer to happen than at 20KHz so measurements like Group delay must be considered in terms of what frequency it is (how long it takes).
Put it this way, he was the first person to figure out how to take an anechoic loudspeaker measurement including the acoustic phase indoors.
How does one exclude all the sound except the direct from the speaker?
If there was something he heard in the things you mentioned, i am sure he would pursue them if alive today. He was a brilliant scientist that rubbed some conventional academic types the wrong way related to making large leaps, but audio was his passion, he made his own tools when none existed and it's hard to stop someone like that...except in his case Cancer in 1987.
In a real way he was one of Audio's Tesla's, not recognized and argued against as he lacked the depth of academic credentials needed for high level ivory tower credibility.
Yeah great exclude him, "he lacked credentials" because he was recruited out of Cal-Tec to work for JPL on satellite technology.
Tom
My old boss at NASA would sometimes say, never get behind anyone 100 percent. I suspect you probably helped support my contention that AES old school audio types have blinders on when it comes to sound. We all live in reality tunnels to some degree. Richard Heyser missed out on some great innovations in audio, the Golden Age of tweaks, as it were. Would he have disapproved? Would they have changed the road he was on, who can say?
AES always had a strong academic bent, that generally implies a pretty strong sense of where the official box is.
So Dick's big mission, the ultimate frustration was finding measurements that capture things he heard.
Maybe he should have hooked up with someone who was able to correlate what was heard with what caused it, Peter Belt. And yours truly. The opposite of an academic or objectivist. There is an entire universe waiting to be discovered by the intrepid audio pilgrim. People have developed very thick reality tunnels over the years, it's almost impossible to break through. People assume certain truths, the more their beliefs are confronted the harder they hold onto them.Made the scene
Week to week
Day to day
Hour to hour
The gate is straight
Deep and wide
Break on through to the other side
Break on through to the other side
Edits: 02/01/23
Maybe, not sure that the aftermarket accessory area existed then -or- where those folks were at 36 years ago when Heyser passed away.
Peter Belt originally was in the speaker business, ortho something. . Ironic, huh? I don't know when he veered away from audio speakers to tweaks. Ah! It's been almost 45 years ago, according to PWB website. So 70s. But there's nothing stopping YOU, yes? It's never too late. I bet you're not interested in such things, and you dismissed such talk as hog swallop a long, long time ago.
Edits: 02/01/23 02/02/23
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