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"Things that cannot be measured"

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yep. me too. If you're taking either naproxen (an NSAID) or the blood pressure med lisinopril (an ACE inhibitor) try going off of it for a while.
Your tinnitus may lessen or go away.
Thanks for the heads up but I'm not taking either, I'm lucky in that it's very minor and I notice it probably once a month. Always bring my earplugs now whenever I'm going somewhere that I know the volume levels are going to be stupidly high as I'd like to keep it that way.
 

ahofer

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oh weird, i take naproxen for my back and wrists pretty often (ibuprofen in the quantities i need for my carpals makes me drowsy) and had no idea it could cause tinnitus. i was also on lisinoprinol briefly, but changed meds as it made me a bit nauseous. fwiw i don't have tinnitus but do have this annoying tendency to hear the bloodflow through my ear structures or head or something who knows. when i was a teenager i complained of tinnitus so they stuck me in an anechoic chamber for a hearing test, which was fine, and i went "oh, wait, sorry, it just sounds like blood flowing through something up there". they went, yah, there is blood flowing up there, and i went, oh, and that was about that.
I get the blood flowing thing fairly often. When I was a kid, my father (a researcher in neurology) told me the real miracle was that I didn’t hear such sounds all the time, given the activity going on in your circulatory system near the ear drum. It does seem to happen when I’m overtaxed in some way, so I’ve always viewed it as a failure of my brain to suppress sound that is, in fact, there.
 

Tom Danley

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We need to be careful about statements like “THD...has little correlation to audibility”. If the THD is vanishingly low over the audible spectrum, then it has high correlation to transparency (which is what all manufacturers at least claim to produce).

Where the correlation is poor is when THD is high. Depending on which harmonic and in what degree, a given THD measurement may not be particularly audible, or even when audible not particularly unpleasant.

But I have a hard time imagining how a device with distortion plus noise at -100 dB or less could sound anything but transparent. It seems to me that any subjective but demonstrable fault would show up as measured distortion.

In the old days, THD was measured at low power and at one frequency. Now, we see plots of distortion vs. power, and distortion vs. frequency.

Also in the old days, we didn’t measure loudspeakers “in the round” and good anechoic on-axis performance (which we did measure) didn’t mean it would sound good in a room with unfavorable early reflections or once the unguided tweeters started beaming, etc. Now that we focus on both directivity and distortion in addition to linearity, we can indeed correlate measurements with preferences, and the properly controlled preference studies showing that correlation have been done.

Rick “agreeing that engineers often fail to articulate operational objectives as the basis for performance measurement” Denney
Hi

Umm, it is true that the absence of something like having any harmonic distortion at all does make it "hard to hear". My point was more that since THD was / is an advertising and marketing number in audio, that without knowing what the frequency the fundamental was and what number and the level the various harmonics were, one has no idea how audible it is or if two items like an amplifier or loudspeaker with the same numbers sound anywhere near alike.

THD made a lot of sense for radio and made sense for audio as an indicator of how well / linearly a signal is transferred or reproduced but the subjective nature of sound makes it much more complicated so far as how that number relates to what we hear hence my statement. For example with music, even harmonics are MUCH less audible than odd ones but with natural sounds (generally not harmonically related) both are undesirable. Our ears are also very frequency dependent so far as how loud a given harmonic sounds relative to the fundamental.
As far as loudspeakers "in the round" I suppose you mean polar plots, they are useful, but for commercial sound room design models, a full sphere must be measured and done anechoically at sufficient distance to be out of the near field so that the predictions hold true at greater distances..
Fwiw, we supply the CLF data sets for some of our larger speakers just for this use;
https://www.danleysoundlabs.com/support/clf-files/
Best
Tom
 

rdenney

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By “in the round”, I mean the spinorama measurements we are now seeing, not the on-axis measurements we used to see. This is the result of understanding that directivity is as important as frequency response in a real room.

The thread is about things that cannot be measured, which is a different topic than things that manufacturers don’t measure or report poorly, particularly in the past. The tests on this forum measure harmonic distortion in a much more complete way than the usual spec-sheet value, such that we can easily assess what harmonics are in play at a range of power levels. The same is true for IMD and noise products. I can even measure in my own listening room the total harmonic distortion, including all its harmonic components shown separately, using free software and a hundred-dollar microphone.

Rick “thinking we are talking about different things” Denney
 

BluesDaddy

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Speaking about measuring things we hear is contingent upon demonstrating they are actually heard through controlled listening tests to a statistically significant degree. People imagine they hear all sorts of things that disappear under controlled tests.
 

Tom Danley

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Hi Rick
"“thinking we are talking about different things” Denney
Well maybe yes maybe no, likely more a different vantage point.
In fact, we can measure just about any physical property one can think of, what one cannot do well is tie a feature in a given measurement to "what it would sound like".
Granted, if one has measured many many loudspeakers there are things one can guess in a set of measurements would correlate to what you hear but many things are not visible in a measurement.
A key issue is we hear in 3d while technically speaking, just two reference points can only capture one axis accurately so our hearing encompasses a great deal that isn't obvious. My post with a link to Doug's LEDR recordings and the work behind it are a sample.

Don't get me wrong either, i am not saying measurements are not important, they are critical to invention of anything new or improving anything old, rather that the connection to what we "see" in a measurement vs hear from it is often more tenuous than some might think and in some cases baffling. Baffling because ones ear brain combo seeks information and without our awareness, discards noise and interference. Often you can't hear flaws clearly but if you defeat the stereo hearing process one can often reveal new things.

If you have a good set of headphones and a good measurement mic, a fun test is to to listen to the microphone in mono with headphones. Best is to wear them for a few min, set the level to sound "normal" listening to household sounds and better yet others talking.

First you will notice all the room sound, your ears have directivity and noise rejection but the mic and headphones defeat that process.
Then, when your comfy, play some of your favorite music through ONE loudspeaker.

If you play pink noise and move the mic around near the speaker, you will easily hear the radiation pattern it produces and often one can find lobes and nulls via headphones.
Most people will hear a dramatic difference, where voices in the room sound pretty normal speakers often sound very different and not in a good way. I would caution that often, once you have heard a flaw in a loudspeaker exaggerated via gen loss recording, it will probably be audible once you go back to normal listening. As a speaker designer, this doesn't tell you what to fix and there is no "number" but it can be a strong arrow pointing to where you need to look.
If you make a generation loss recording in an anechoic condition, you hear an increasing caricature of what's wrong and like electronics and recording tape, the more generations one can pass with acceptable quality, the more faithful the process. You would be shocked or a least surprised to hear how few generations most loudspeaker can go and still be listenable.
By far, loudspeakers are the least faithful to the signal of the entire chain, on the other hand if you can pass a number of generations, that doesn't hurt when when captured on a cell phone or camcorder.
If you have headphones, here are a couple recordings I made, testing a new speaker at my shop and at a couple old sound checks.

https://www.dropbox.com/s/g61e95t8eve7gux/20160623090318.mts?dl=0

https://www.dropbox.com/s/va4mihvefqyxk24/20130723140018.mts?dl=0

https://www.dropbox.com/s/tnsw5mb4v5vdlwq/20120726122124.mts?dl=0


Best Regards
Tom Danley
Danley Sound Labs
 
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rdenney

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I agree that speakers are the weak link, and the least likely to live up to their measurements in a real room. And with speakers, we think of 1% THD as being superb—noise products only 40 dB down from the sum. And in the bass region, we might see ten times that even with the best speakers. Generational losses would add up pretty quickly.

And I completely agree that how the sound field fills a room is important, but part of what makes it important is how directionality is perceived. What makes them perceivable are the effects of superimposing reflected sounds on directed sound—effects that can be measured.

But we also know what listeners of all categories prefer, and what characteristics describe those preferred attributes. Within those categories and attributes, variations exist, of course.

The thread wasn’t just about speakers, of course. We see the same statements in reference to amplifiers, preamps, and even DACs, with distortions orders of magnitude less than speakers, and even orders of magnitude less than what we can (demonstrably) hear.

As for me, I don’t want audible even-order harmonic distortion even for music, because it changes the timbre of instruments, particularly brass instruments.

Rick “key word: demonstrably” Denney
 

ahofer

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There’s a whole thread on this topic, but there’s at least one aspect of speakers about which I haven’t seen a convincing, researched measurement story - that’s size impression. My Harbeth’s sound *huge* in comparison to my KEF LS50Ws (even with a subwoofer on the latter). I’m still not convinced I know why, although perhaps some of it is in my head. Come to think of it, my JBL L830s also sound bigger than the KEFs, but somewhere in between. The JBLs are in another house, so it’s harder to compare directly.

Within the thread linked above, one hypothesis is distortion, and I believe the KEFs need a high crossover (200Hz) to avoid rising distortion in lower frequencies. My sub isn’t set that high right now, I’ll have to try it when I get back.

Another is that a wide baffle will increase size impression at the expense of other attributes. The Harbeths are certainly wider baffle speakers.

Finally, this post pulls from Toole to suggest that greater directivity from 100-700Hz (known as the “envelopment region”), also achieved by wider baffles, makes the difference.
 

Sal1950

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My Harbeth’s sound *huge* in comparison to my KEF LS50Ws (even with a subwoofer on the latter). I’m still not convinced I know why, although perhaps some of it is in my head.
Curious as to what property of these speakers you relate to "sounding huge"? Are you referring to the size of the sound-stage you hear in playback?
Or that difficult to describe property I hear from many horns or other speakers with high efficiency. Its a sound that more closely relates to hearing music played under live conditions, like at a concert, etc. A large frontal presentation that still differs from the sound-stage in a strange way.
Or is there some other attribute that gives you the impression of "huge"?
 

rdenney

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Traditional exponential horns seem to me to present the ear with a much higher proportion of on-axis signal and much less of reflection. They are the opposite of wide-directivity that sounds accurate over a large part of a typical residential room, but they demand a sweet spot unless the room is so large that one can be far enough away for the beam to become large. They always, it seems to me, to give the sense of coming from “over there”, where wide-directivity speakers create an encompassing surround field.

I don’t know how that relates to the perception of size, but it does give a different sense of localization in the a room.

Rick “‘loud’ + ‘over there’ = ‘live’?” Denney
 

ahofer

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Curious as to what property of these speakers you relate to "sounding huge"? Are you referring to the size of the sound-stage you hear in playback?
Or that difficult to describe property I hear from many horns or other speakers with high efficiency. Its a sound that more closely relates to hearing music played under live conditions, like at a concert, etc. A large frontal presentation that still differs from the sound-stage in a strange way.
Or is there some other attribute that gives you the impression of "huge"?
It’s a good question, and I will freely admit I’m fully in the realm of the subjective. The term “envelopment”, that Toole uses, describes what I’m talking about best, I think. Not necessarily a very wide soundstage, but one that feels more on the scale of a real performance (my live reference for listening is almost entirely classical - while I love rock and Jazz, the performances and studio recordings tend to be unique, sound-wise). Imagine the difference between a small desktop/subwoofer system from a distance and your high-end setup. It’s weird, because I typically use the KEFs pretty near field - like 6 feet - and the Harbeths at more like 12-15 feet.

It could even be the product of more chaotic reflected sound. My old Magnepans also did well in this department, although image stability was inconsistent, and they could be fatiguing. And the visuals may be throwing me off, of course.
 

Sal1950

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It’s a good question, and I will freely admit I’m fully in the realm of the subjective, My old Magnepans also did well in this department
No problem, I freely admit to feeling strange and off balance when talking about this stuff since much of it is so subjective. Maggies and a few other panel speakers have also given me the listening impression of a large presentation, a attribute I give to the large wavefront of their reproduction. OTOH it very well could be a visual bias created by the panels size, I just don't know.
I know, it's only Hi Fi but I like it, like it, yes I do. LOL
 

audio2design

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Sorry, you can go around to any direction with proper considerations of direct vs. reverberant sound plus HRTF's. Furthermore, you can even do elevation, although with less accuracy.
Probably should have been more clear, I was not considering the implementation of HRTFs, but I mentioned signal processing later in that post.
 

Frank Dernie

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First you will notice all the room sound, your ears have directivity and noise rejection but the mic and headphones defeat that process.
Very interesting indeed.
I noticed when I first started making recordings that microphone position made a greater difference to the recording than one would expect by listening at the various microphone positions tried.
I assume it is our ability to "hear through the room" a capability a microphone doesn't have!
Having observed this I balanced my recordings by microphone position, starting in mono 50 odd years ago.
 

BluesDaddy

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It's called Intuition. some have more or less of that so called 6th sense. Just as the saying goes at this time and age, one would have to believe that there are Psychics, or "mind reader's" But here in this Country we only use those "Perceptions" with hearing on a need to in "Double blind test" I believe you guys are over thinking this Psychosis of hearing, In the Truth of finding Audio Facts that can Not be applied.
I assume this was created by using a translator. I any case, it's nonsense.
 

j_j

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From your point of view maybe. Than again (I know No one can read my mind). But your Dr. Gilroy?
Who is this "Dr. Gilroy"? My first thought was "Gilduroy Lockhart" to be honest here.

1) No, there is no reason to accept psychics are anything but cold readers or worse
2) Not sure where a "psychosis" is involved here.
 

j_j

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That was "Pun" psychosis, but reading past 4 or 5 post on OP's thread will go round and round of endless Debating. Just thought I put in a shot. Human hearing is above and beyond any speakers ever built, including cheap ones.
Nah. It's not the speakers, it's how the complex information is presented to the ears. Remember, two channels is not enough, something shown in 1933 by Steinburg and Snow, that remains unchallenged technically to this day.
 

Kal Rubinson

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It's called Intuition. some have more or less of that so called 6th sense.
There are already at least 7 physiologically defined senses so what you call "intuition" doesn't warrant such a high position or, more likely, not at all.
 
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