A question for the speaker manufacturers on here....

[CnoEvil]

....what is the thinking behind having speakers, whose top frequency range, far exceeds the limit at which humans are able to hear? Do these frequencies even exist on current formats, and can they be passed on with current sources and amps?
This whole topic got triggered on another thread, but I felt probably deserves its own.

I suppose I'm looking to the likes of AE Jim and Dean Hartley to give some insight as to the philosophy behind this, as they both produce speakers that go well above the 20 KHz limit.

Some speakers that go for this are:

MA Platinum......100KHz
Kef Reference....60 Khz
AE Reference.....40 KHz
Focal Utopia.....40 KHz
B&W 800 series...28 Khz

Don't let the title put people off giving their view, but I wanted to make this whole question more visible, in the hope of getting an answer.

Personally, I find the race to get the tweeter with the highest frequency response, an interesting one...is it based on concrete science, or just pushed by the marketing division, to find a USP and "point of difference?".

Cheers

Cno

 

[Midisurf]

Good question. I'm not a speaker manufacturer but found this on Monitor Audio website.

"The gold dome tweeter is formed from a ceramic-coated aluminium/magnesium alloy, gold anodised to a specific thickness for ideal stiffness and damping characteristics. Its new profile and surround geometry have been developed using advanced modelling tools, to provide the optimum qualities for accurate sound reproduction. The new design moves the first order of breakup to beyond 35kHz, producing a linear response way beyond audibility, which matches the wide frequency bandwidth available from HD music and cinema sound formats."

I think my Dacmagic goes all the way upto 192kHz but could be wrong if it's the same thing. Maybe it's just for technical braggery and completely pointless, used for marketing just like 5000DPI mice when you only need 25000DPI at most.

 

[CnoEvil]

Good question. I'm not a speaker manufacturer but found this on Monitor Audio website.

"The gold dome tweeter is formed from a ceramic-coated aluminium/magnesium alloy, gold anodised to a specific thickness for ideal stiffness and damping characteristics. Its new profile and surround geometry have been developed using advanced modelling tools, to provide the optimum qualities for accurate sound reproduction. The new design moves the first order of breakup to beyond 35kHz, producing a linear response way beyond audibility, which matches the wide frequency bandwidth available from HD music and cinema sound formats."

I think my Dacmagic goes all the way upto 192kHz but could be wrong if it's the same thing. Maybe it's just for technical braggery and completely pointless, used for marketing just like 5000DPI mice when you only need 25000DPI at most.

MA obviously didn't think 35 KHz was enough, and nearly trebled it with their new ribbon tweeter. I seem to remember them highlighting it as a uniqe achievement.

 

[kevinJ]

I guess it might be just a spec to help sell those speakers. I'm 30, and I'm sure I can't hear 20kHz anymore, let alone 30 or even 40. Maybe it's just a way to please the canine familymembers?

In the bass department, it's a different story. Frequencies below 20Hz can no longer be heard, but they can be felt.

 

[CnoEvil]

I guess it might be just a spec to help sell those speakers. I'm 30, and I'm sure I can't hear 20kHz anymore, let alone 30 or even 40. Maybe it's just a way to please the canine familymembers?

In the bass department, it's a different story. Frequencies below 20Hz can no longer be heard, but they can be felt.

That is exactly the case they have to answer. I find it hard to believe that they would invest a large amount of time and money, if their only goal was a bit of marketing and "one-upmanship."
I have heard there is science behind it, but apparantly that has been discredited (as highlighted on another thread by Andy8421).

 

[Thumpa]

My understanding is that while these frequencies can not be heard, they (do exist and work in the same way and) blend in with those frequencies which can be heard, apparently adding to the (humanly audible) mix.

I was particularly curious about this myself (what's the point?) but with the above explanation, I was satisfied, it seemed quite logical to me ... kinda like garlic in the olive oil (sorry).

Unfortunately I can't recall the source off the top but I'll have a look around, try to get back.

 

[Frank Harvey]

Harmonics.

 

[CnoEvil]

Harmonics.

Agreed, and as stated previously, that is my understanding as well. What I'm trying to ascertain, is whether this science is based on discredited research by Tsutomo Oohashi, or not....hence the title of the thread. If anyone can shed light on the need for an ever increasing high level frequency response, it's the people who implement it.

As in all things hifi, it's trying to weed out fact from fiction and marketing spin. :?

EDIT. There is certainly a lot going on above 20 KHz as researched here:
http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

 

[Thumpa]

Well, I've been where I didn't intend / wanna go but here's a sample, suggesting inaudible HIGH frequencies are in fact attractive to humans, despite being unheard (and this, presumably, is at least one aspect of what speakers containing high-frequency components [HFC] achieve):

"Psychological evaluation indicated that the subjects felt the sound containing HFC to be more pleasant than the same sound lacking an HFC. These results suggest the existence of a previously unrecognized response to complex sound containing particular types of high frequencies above the audible range. We term this phenomenon the “hypersonic effect.”

Studies ... concluded that listeners did not consciously recognize the inclusion of sounds with a frequency range above 15 kHz as making a difference in sound quality. Nevertheless, and interestingly enough, artists and engineers working to produce acoustically perfect music for commercial purposes are convinced that the intentional manipulation of HFC above the audible range can positively affect the perception of sound quality (Neve 1992).

(It was proposed) SACD and DVD-audio have a frequency response of up to 100 kHz and 96kHz, respectively ...

And (although) the biological sensitivity of human beings may not be parallel with the “conscious” audibility of air vibration, the natural environment, such as tropical rain forests, usually contains sounds that are extremely rich in HFCs over 100 kHz.

It's well-known humans seek out natural environments for tranquility and relaxation etc.

http://jn.physiology.org/content/83/6/3548.full

 

[Thumpa]

Waddya on about CNO? Science based on discredited research?

It'd be nice if you included that you already knew the answer to your question, better yet if you laid out the academic references, that you're all over the subject at a particular level.

Why don't you ask Tsutomo Oohashi about his discredited research?

And AE Jim and Dean Hartley? Ask THEM

What is this place? Conspiracists' corner?

I thought it was about Hi Fi -- music and kit.

 

[jaxwired]

There's a very simple and obvious answer. This is done so your dog can enjoy your hifi too. In fact, dogs prefer MA Platinum 2 to 1 over other brands.

 

[Anonymous]

It drive me crazy, I can't track back the web page on that topic...

Anyway, long story short, this theory was that having these ultra high frequency waves "movement" were king of helping creating a better enviroment that would help the frequency that we can hear. So, to sound better.

It was making some sense. But I also like the dog theory too :rofl:

 

[Anonymous]

Possible answers as far as I can see.

We can somehow sense the ultrasonic frequencies outside of our hearing range - doubtful, but?

Higher frequencies have an effect on lower frequencies in harmonics - Hugely doubtful, sounds like made up gibberish.

Record companies and speaker manufacturers are in cahoots to sell HD music to help squeeze the last drop of money out of the market, after all it's no use having a download that can go to 48 Khz and speakers that go to 20 - plausible but maybe a bit ott.

My personal favourite is the Ferrari analogy given in the other thread (ie make something that performs well way above the level it needs to so it isn't struggling lower down - probably complete bonkers, but sounds good.

Ultimately though, It feels as if people, with no more than a basic understanding of the science involved, enjoy coming up with x files style theories along the lines of spontaneous human combustion and telekenisis all wrapped in a hugely pseudo-scientific wrapper to make it sound good.

If I was to hazard a guess, is it's simplythat drive units are measured for frequency response, and why not claim that which they can be measured to? It doesn't matter that no human alive can hear above around 22 Khz, and the vast majority not much over 18 Khz, if a drive unit, under testing, shows flat to 40 Khz, it looks like a bigger (is better) number.

ie, which sounds better on the specs?...

22Hz - 20 KHz

18Hz - 22 KHz

18Hz - 44 Khz

I've even chosen headphones with these measurements in mind, not really thinking about it...

 

[CnoEvil]

Waddya on about CNO? Science based on discredited research?

It'd be nice if you included that you already knew the answer to your question, better yet if you laid out the academic references, that you're all over the subject at a particular level.

Why don't you ask Tsutomo Oohashi about his discredited research?

And AE Jim and Dean Hartley? Ask THEM

What is this place? Conspiracists' corner?

I thought it was about Hi Fi -- music and kit.

Thumpa, I think you've got me wrong. I have always assumed that there was merit in having frequencies above our hearing range, and it was Andy8421 who talked about the research being discredited on this thread (post no.4):
http://www.whathifi.com/forum/hi-fi/for-all-the-hifi-skeptics?page=1

I'm just trying to make sense of it all, and where better to do that than on a hifi forum.

There is no conspiracy here, only a question asked of the people, who are in the best position to know the answer.....the speaker companies who contribute on this forum.

Cno

 

[altruistic.lemon]

Mate, if you want to understand it, head along to your local uni library and start some research followed by reading. There's heaps of research papers out there covering the topic of hearing, ultrasonics etc.

You won't find an answer on a hifi internet forum, nor, to be truthful, on the web unless unis have publisher their stuff on it. If you do find stuff on the web, it's 99% sure to be someone's whacky opinion backed up by zilch. Even something as basic as cooking, food and nutrition gets mangled by too many crazed idiots masquerading as experts.

Also, you're being given opinions here, and they don't count for anything, because they're just that and may be based on what Fred told you down the local after a couple of tinnies. What you need to do is suss out the facts

 

[Inter_Voice]

This is really an interesting topic. I found that not only speaker manufacturers are trying their efforts to extend the FR up to 100KHz, even a lot of amplifier and the CDP manufacturers are doing the same thing. A lot of high ended amplifier and CDP maunfacturers claimed that their products has up to 80K-100KHz linear FR.

Recently I have come across some articles saying that when palying SACDs and DVD-A the player needs a much higher FR over that of 20KHz to get the best of the music quality. For normal CDs there is no such requirement. Please don't ask me why :wall:

 

[The_Lhc]

Higher frequencies have an effect on lower frequencies in harmonics - Hugely doubtful, sounds like made up gibberish.

Really? It's only gibberish if you have no understanding on how sounds are constructed.

Have a look into the background behind Fourier analysis (see if you can fin Marcus De Sautoy's recent Radio 4 podcasts about mathematics, one of them deals with Fourier, actually it might have been on his BBC2 show as well, with pictures, which makes it easier to visualize the waveforms), every sound you hear can be constructed out of combinations of basic sine waves of different frequencies, you look at an oscilloscope trace of a complex sound, such as brass instruments and it looks a mess, but break it down and you find that it's just combinations of sine waves of different frequencies. The point of upper harmonics is that even though we can't hear them directly they will add to the harmonic frequencies that we can hear (if you add two sine waves of the same frequency together they combine and increase, the same applies to harmonic frequencies). Of course if they're out of phase they'll subtract. In either case the presence of the harmonic frequency will alter the sound of the frequencies we can hear. 40kHz is a harmonic of 20kHz (and 10kHz and 80kHz...).

This may (note: may) explain why people don't like mp3 as much as lossless audio, mp3 specifically "throws away" the frequencies we can't hear, if that removes harmonics it's possible people could subconsciously notice it. That would particularly apply to orchestral music, you're much more likely to get those sort of upper harmonics from strings and brass instruments.

Ultimately though, It feels as if people, with no more than a basic understanding of the science involved, enjoy coming up with x files style theories along the lines of spontaneous human combustion and telekenisis all wrapped in a hugely pseudo-scientific wrapper to make it sound good.

Irony overload...

 

[plastic penguin]

Call me an old fuddy-duddy but do we really need to know such specs? Surely if a component sounds good that's all matters.

Can't remember the last time I looked at any spec sheet...

It is an interesting discussion, I'm certainly enjoying it. However, interesting discussions become meaningless when it comes switching on the hi-fi, and a big smile spreads across your face.

 

[Richard Allen]

Possible answers as far as I can see.

We can somehow sense the ultrasonic frequencies outside of our hearing range - doubtful, but?

Higher frequencies have an effect on lower frequencies in harmonics - Hugely doubtful, sounds like made up gibberish.

Record companies and speaker manufacturers are in cahoots to sell HD music to help squeeze the last drop of money out of the market, after all it's no use having a download that can go to 48 Khz and speakers that go to 20 - plausible but maybe a bit ott.

My personal favourite is the Ferrari analogy given in the other thread (ie make something that performs well way above the level it needs to so it isn't struggling lower down - probably complete bonkers, but sounds good.

Ultimately though, It feels as if people, with no more than a basic understanding of the science involved, enjoy coming up with x files style theories along the lines of spontaneous human combustion and telekenisis all wrapped in a hugely pseudo-scientific wrapper to make it sound good.

If I was to hazard a guess, is it's simplythat drive units are measured for frequency response, and why not claim that which they can be measured to? It doesn't matter that no human alive can hear above around 22 Khz, and the vast majority not much over 18 Khz, if a drive unit, under testing, shows flat to 40 Khz, it looks like a bigger (is better) number.

ie, which sounds better on the specs?...

22Hz - 20 KHz

18Hz - 22 KHz

18Hz - 44 Khz

I've even chosen headphones with these measurements in mind, not really thinking about it...

I can't speak for AEJim or Dean but I'll have a go from my own point of view. To do this, I have to go back to a few basics so if I'm "teaching to suck eggs", apologies in advance. Here's how I see it. bonkers as it may be.

First, ( get yer heads round this one guys ) we don't hear anything!!. We feel it. When a loudspeaker makes a forward stroke, it compresses the air in the listening space which goes down your outer ear and moves the round window i think on the inner eardrum. This is full of fluid which is compressed accordingly and on a bone in the inner ear are a load of tiny hairs.

These hairs are excited by the compression of the fluid and sends an impulse to the brain which is what we perceive as hearing. Unfortunately, from the time we are born, these little hairs are dying off hence when we get to middle age, our hearing tends to 'roll off' due to this.

Frank Harvey is right when saying Harmonics. Your hearing may be rolling off at around 14 to 15kHz but the upper harmonic of that is around 30K and if not addressed, hurts like mad! ( Shrieky treble ).

To prove this, I actually designed a loudspeaker that had a flat response to 20K. Played music through it and nearly blew me head off with the HF yet it measured fine. so I re-designed the treble section by ear and trial and error. Eventually, I got it right. Not just to my ears but to other people as well. It was superb in every way. I then measured it. At 20K, it was nearly 9dB down!.

What I realised was that I had designed the loudspeaker to mimic the response curve of the ear. 9dB at 20K may sound a lot but at the upper harmonic of 40K, the ear can tolerate it. What was this loudspeaker I hear you ask??.

Oooh sorry. It was the Arcaydis AK3. 5 stars twice.

Sorry if I've put you all to sleep guys.

 

[Anonymous]

This may (note: may) explain why people don't like mp3 as much as lossless audio, mp3 specifically "throws away" the frequencies we can't hear, if that removes harmonics it's possible people could subconsciously notice it. That would particularly apply to orchestral music, you're much more likely to get those sort of upper harmonics from strings and brass instruments.

And having tested this to exhaustion on myself and a few others, my own personal opinion is that to most people, a high bit rate MP3 sounds every bit as good as a lossless CD rip. In fact, I bought some 24/96 from Linn too, it sounded great and I was prepared to keep paying for the "extra quality" but to my ears it's... all in the mastering, as it sounded identical all the way down to 200 Kbps MP3 once I decided to start experimenting.

So other than bad examples from the early days of the format, hearsay and passed on half-truths, I think "people don't like mp3 as much as lossless audio" is rather a sweeping statement. I'm perfectly happy to listen to MP3 on all my systems.

As for the harmonics... I can't hear it. I'd love to see someone do a proper scientific blind test with a good spread of people though, as I do remain open on the possibilty that some may be able to.

 

[The_Lhc]

As for the harmonics... I can't hear it.

How do you know? Prior to this thread you didn't even know what they were.

 

[Anonymous]

As for the harmonics... I can't hear it.

How do you know? Prior to this thread you didn't even know what they were.

You know that do you? What I intimated was that I didn't think it was particularly likely that a 40 KHz harmonic would change the lower notes to an audible degree. I know what a harmonic is.

And even if I didn't, the fact that I have listened to the same tracks in 24/96, 16/44.1 and MP3 format, and couldn't tell a difference kind of means the same as "I can't hear it".

 

[visionary]

There's a very simple and obvious answer. This is done so your dog can enjoy your hifi too. In fact, dogs prefer MA Platinum 2 to 1 over other brands.

I thought they always had done...

 

[krazy_olie]

I may be taking a stab in the dark here.

I think having 40khz frequencies in there or not doesn't make a difference, but indirectly it is useful. A speaker's response would usually slope as frequencies get higher and higher, if your max "audible" (even though it's not audible) response of the speaker is 40khz it would ndicate that it has potentially improved the response of 15khz compared to a speaker which "goes up to 20khz" whose response will have sloped way done by then.

Whether 40khz signals are actually present or not is sort of irrelevant you can't hear them, removing them doesn't affect the 20khz signal. If you took a fourier transform of a signal that had lots of frequencies present including 40khz, you would get the frequency responsesand 40khzwould be present. Then you take a perfect low pass filter to leave onl everything below 20khz say, EVerything below would be completely unaffected, everything above would disappear.

The point is though is that a speaker is not a perfect low pass filter, it doesn't just cut off, so essentially moving up the frequency at which frequencies get cut off outside the human hearing range reduces the effect on frequencies inside the hearing range

 

[Frank Harvey]

My take is that, if it was there before, then it should still be there after, whether I can hear it or not