Upper end extension... what gives?

[agarwalro]

Why are audio manufacturers and "audiophiles" all goo-ga about upper end frequency extension. I keep seeing these claims for speakers, amplifiers, etc. giving readouts for frequencies way beyond human capacity for hearing.

Brand X speaker has flat FR 250Hz - 45KHz.
Brand Y amp has +/- 0.1dB FR from 20Hz - 100KHz

Vifa, planar tweeters and all that claim extension beyond 20KHz... I say WTF?

I am 29, have listened to loud music and sometimes abused my hearing playing FPS games over headphones. Meaning I cant hear squat over 17 or 18KHz tops... By the age I might actually afford "audiophile" equipment, I probably wont hear a tone over 16KHz. Even if someone has been very careful with their hearing, by age 21 most will not even hear a 20 KHz tone.

So what am I missing?

 

[Seth=L]

I have always wondered this as well. I want to say it is a marketing ploy for the most part. I have heard claims that it ensures the tweeter won't have audible break-up when driven hard, but it sounds fishy to me.

 

[no. 5]

what it can do 20Hz and under is more inportant to me than 20kHz and over, I can only hear up to about 18kHz - 19kHz anyway, so why would I want 100kHz? just seems weard.
but the idea seems to be that above 20kHz can somehow be "sensed", and having speakers and amps that can go that high will inhance the listening experince.

 

[MDS]

I can think of two possibilities:

1. Maybe because the upper frequency respose extends so high the tweeter can be made more linear in the range that we actually can hear.

2. The school of thought that says although we cannot hear such high frequencies they still influence the music in the range that we can hear. This is an often stated reason in support of high sampling frequencies for digital audio other than the one that does have merit; ie that quantization noise is pushed into much higher frequencies beyond our hearing.

I have a hard time accepting some magic 'X' factor from frequencies beyond our range of hearing that would somehow influence the frequencies within our range of hearing but I suppose it is still a reasonable topic for research.

 

[mtrycrafts]

I have a hard time accepting some magic 'X' factor from frequencies beyond our range of hearing that would somehow influence the frequencies within our range of hearing but I suppose it is still a reasonable topic for research.

If, a very big if, that ultrasonic frequency affects the ones audible before the sound waves hit the recording mic, that audible band will be also recorded as part of the audible band will be placed on the CD and reproduced. No need to record it. Besides, not many tweeters do real good ultrasonics and at levels that may be audible, well above 100dB spl threshold. On the other hand, if it affects the audible band only after it is reproduced by the tweeter, then we are talking IM distortion. This was demonstrated in some papers that refuted the ultrasonic claims of some. That is what may be heard.

 

[Buckle-meister]

Why are audio manufacturers and "audiophiles" all goo-ga about upper end frequency extension...what am I missing?

It's to do with the environment. As I'm sure you know, most speaker cabinets are made from MDF in order to reduce the number trees that're cruelly chopped down, ending their precious lives prematurely. With global warming on the 'up and up' as it were, the envioronmental lobby now has enough clout to match that even of Darth Vader in his prime - a sinister thought indeed.

Now, as I was saying, the environmentalists - read 'tree-huggers' - have raised awareness of the plight of the Earth in the simple commoner so much so that no longer is it seen as enough to make speaker cabinets from MDF rather than real wood. No, even the speaker drivers have to be made more environmentally friendly, and in this respect it's been found that by extending the tweeter's frequency response into the ultrasonic range, bats are no longer affected by the breakup mode of the driver; something that previously gave them terrible migraines. As an added bonus, bats are now frequently seen flying at super-sonic speeds.*

I trust this answers your question satisfactorily.

*The recent case of an American fighter-jet pilot confusing a mig for a bat has been neither confirmed nor denied by the USAF.

 

[stratman]

It's to do with the environment. As I'm sure you know, most speaker cabinets are made from MDF in order to reduce the number trees that're cruelly chopped down, ending their precious lives prematurely. With global warming on the 'up and up' as it were, the envioronmental lobby now has enough clout to match that even of Darth Vader in his prime - a sinister thought indeed.

Now, as I was saying, the environmentalists - read 'tree-huggers' - have raised awareness of the plight of the Earth in the simple commoner so much so that no longer is it seen as enough to make speaker cabinets from MDF rather than real wood. No, even the speaker drivers have to be made more environmentally friendly, and in this respect it's been found that by extending the tweeter's frequency response into the ultrasonic range, bats are no longer affected by the breakup mode of the driver; something that previously gave them terrible migraines. As an added bonus, bats are now frequently seen flying at super-sonic speeds.*

I trust this answers your question satisfactorily.

*The recent case of an American fighter-jet pilot confusing a mig for a bat has been neither confirmed nor denied by the USAF.

Was that a FOX BAT? Cool theory BTW. Supersonic bats must have their wings coated with carbon, carbon in order to avoid leading edge melting temperatures.

 

[blowinch]

I can't hear over 15k unless that was a prank by my friend who playes the drums and goes to post rock wall of noise concerts. This is a link to an article. it doesnt help much.


http://mixonline.com/mag/audio_world_above/

 

[stratman]

It's bogus, unless you have bat hearing.

 

[j_garcia]

I believe it is #1 of what MDS said. The tweeters range is beyond our hearing, and since it moves one of the points where the tweeter doesn't perform as well beyond the typical hearing range, it should allow more smooth response in the audible range for a tweeter. Whether or not it actually works, who knows?

 

[HiJon89]

I think it's just their to wow people. Kind of like when Logitech sells their computer speakers and say its a 550W surround sound system or w/e, people are supposed to be impressed and want to buy it.

 

[j_garcia]

I honestly don't care if it goes above 20K; I only care if it sounds good. When I look at response figures, I am more concerned with the -3dB on the low end rather than the top end.

 

[Resident Loser]

Supposedly...

...components that have a wideband response have a more linear FR within the audible band and will not truncate upper harmonics...According to some, those ultrasonic, upper harmonics do have an effect on what we hear...

It may be indicative of a bit more care in design and the choice of discrete components rather than ICs and op-amps...more wiggle room, less of a brick-wall effect...

jimHJJ(...then again could just be hogwash...)

 

[agarwalro]

Thanks for all the responses. I am glad there are more folks that feel the same way.

Buckle, first thought that came to mind was "conspiracy theory". Thanks for the laugh.

I suppose one way to test the so called benifit of having linearity up to 100KHz could be tested by using a low pass filter set to 20KHz. Play tracks with and without the filter engaged and see if that makes any audible difference.

Thoughts?

 

[davo]

I suppose if it was a choice between a good quality tweeter that easily reproduces sounds near 20khz with minimal distortion, and one that does distort badly and struggles with the same frequencies, I know what the obvious choice is.
Like with any product, the quality ones are capable of performing way beyond what is practicle (think of a ferrari) while the poor quality ones will struggle to pass muster. (a rusted out,smoke blowing ford)
So if a tweeter can 'only' reproduce up to 17-18khz, chances are it is struggling to do so, at least more so than one capable of reproducing say 30khz.

 

[Dolby CP-200]

It's bogus, unless you have bat hearing.

You hit the nail spot on mate, it’s the same with 96KHz bit rate things, crazy I mean unless I’m a bat there’s no one it’s impossible for me to hear even if I was 16 years old again. I guess in the subconscious mind it’s kinder there but what doses it sound like?

Anyway here’s something else that’s been on my mind for a few years now.

What about turning high frequencies into low frequencies?

Frequency Range of Human Hearing
http://hypertextbook.com/facts/2003/ChrisDAmbrose.shtml

How a Bat's Sensor Works
http://www.bbc.co.uk/dna/h2g2/A748749

 

[Seth=L]

(...then again could just be hogwash...)

Yes, hogwash.

 

[Resident Loser]

Aaa...err...

...You hit the nail spot on mate, it’s the same with 96KHz bit rate things, crazy I mean unless I’m a bat...

...sampling rate and audible FR are two different things...96k (sampling not bit rate) is nearly 5X the human hearing range as opposed to the Nyquist number which dictates that twice the bandwidth (44.1kHz in Redbook practice) is sufficient for digitizing an analog waveform...

jimHJJ(...bat-hearing not required...unless you are interested in listening to data streams...)

 

[masak_aer]

The answer is here

It has simple explanation, just like "Bush" answer on the Conan show,"how do you figure you need 21,500 more troops in Iraq? Where does the number come from?". "Well, i figure we need 6,000 troops, but to be on the safe side, i double the number." (not exactly what "he" said, but more or less like that ).

To be on the safe side, you always want your product to be higher than the allowable standard,e.g.: cars that go a lot faster than the highest allowable speed limit? This same psychological marketing plot applies to speakers. Why do we need a super fast computer when all you do is browsing the internet and reading AH when the standard speed computer will be just sufficient enough? The marketing plot suppose to make you feel good than you are better than the standards or that you think that when you need to go beyond the standard you have the capabilities to do it (which you might never).

On a side note: some people like to listen to their music or watch movies with their dogs and cats and bats . They want the "other" members of the family to enjoy the 2.1, 5.1 or even 7.1 as well.

JMHO...

 

[stratman]

It has simple explanation, just like "Bush" answer on the Conan show,"how do you figure you need 21,500 more troops in Iraq? Where does the number come from?". "Well, i figure we need 6,000 troops, but to be on the safe side, i double the number." (not exactly what "he" said, but more or less like that ).

To be on the safe side, you always want your product to be higher than the allowable standard,e.g.: cars that go a lot faster than the highest allowable speed limit? This same psychological marketing plot applies to speakers. Why do we need a super fast computer when all you do is browsing the internet and reading AH when the standard speed computer will be just sufficient enough? The marketing plot suppose to make you feel good than you are better than the standards or that you think that when you need to go beyond the standard you have the capabilities to do it (which you might never).

On a side note: some people like to listen to their music or watch movies with their dogs and cats and bats . They want the "other" members of the family to enjoy the 2.1, 5.1 or even 7.1 as well.

JMHO...

I want a bat, a Flying Fox, it looks like a Chihuaha with wings. My wife said no.