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Mr. Widget
09-23-2006, 07:59 PM
I pulled this form another thread as I have been quite interested in the subject for sometime and thought it deserved it's own thread instead of derailing yet another thread with an Off Topic ramble.


A more serious question to me and possibly others is, As we age, Where does the human ear rool off?
I am sure we are all different in this respect but it is painful to not be able to hear what others apparently can.

I can hear fine, don't need a bionic ear to watch TV nor do I need it loud.

I just can't seem to hear this roll off. I can't hear my speaker wires. I can't hear any difference between $10 interconnect or $1000 ones.

Is it my ears or is there really people out here that have bionic ears and can really hear all these tweeks?
As with everything else in life aging is a function of genes and wear and tear. Typically females hear more acutely than males do. (But for some reason don't seem to get the audio bug like we do.) We do not all start out with the same level of hearing ability (more of the genes part) and as we age our hearing slowly degrades. If you are an avid hunter, a musician who played loud amplified music, or if you worked in a noisy machine shop or other noisy industrial environment you will very likely have damaged your hearing. (Accelerated the aging of them.) Here are guidelines for us to delay or reduce hearing loss. I took this from an Audiology website:

Preventing Presbycusis (Hearing Loss due to Aging)


If you don't have a hearing problem, taking the following steps may help reduce your chances of developing one. And if you already have presbycusis, following these guidelines may help you keep the problem from getting worse.

Avoid loud or prolonged exposure to noise.
When you can't avoid noise, wear ear protection.
If your ears produce excessive earwax, have your ears cleaned periodically by a health care professional. (Do not use cotton swabs, as you will lodge more earwax even deeper into the ear canal than the small amount of wax you will remove.)
Avoid ototoxic drugs. If you're taking one already, talk with your doctor and see if there's a less-ototoxic alternative.
Stay healthy and be mindful of risk factors, such as hypertension.
How does our hearing roll off due to age?

Obviously it varies from individual to individual... but it typically starts up top and works down. At 18 I could hear a 20KHz sinewave... today at 47, I can barely hear a 16KHz sinewave.

Being able to hear TV, the telephone, and general speech intelligibility requires hearing up to about 5KHz... above that are only overtones and harmonics. They are incredibly valuable for flushing out the difference between different instruments and adding spatial ques and general "reality" to the music, but I suppose if you no longer hear them in live music, you won't miss them if they are lacking from your Hi-Fi.

Speaker cable, interconnects, and electronics? I have yet to hear a speaker cable that "improved" the sound. There are some that mess around with the sound, but good quality copper all sounds the same to me and to many of the people that I have talked to... some are of the "golden eared" set. Interconnects tend to have more of an impact, but even here... the clearly superior interconnect is rare. With both interconnects and speaker wire the quality of the connection is more important the the wire in between. Electronics do have a marked effect on the sound... simple high quality electronics tend to sound superior to heavily feature laden pieces of equipment.

Back on the subject of hearing and aging and anecdotal evidence...

I have had two older forum members over at my house at different times while I was testing tweeters. In both cases while taking an impedance measurement of the tweeters they were swept with sinewave pulses starting at 22KHz and sliding down the scale I heard nothing until the 16KHz frequency was pulsed. These two individuals heard nothing until below 10KHz... one first heard the signal at around 9.5KHz and the other around 9KHz.

Based on this info we might write off their hearing above 10KHz and think that they don't need a speaker that responds above that frequency. That was certainly my first thought. However as I have spent time with both of these individuals and talked about specific drivers, their sonic signatures, and simply what has worked and what hasn't... it has become apparent that they both did hear above the 10KHz point. The only conclusion that I could make was that with music as a source, we are able to hear higher frequencies than we do when listening to pure sinewaves.

Another anecdote:

I had my hearing tested not too long ago by a friend who is a pediatrician. She measured my hearing and was surprised to discover that I could not only pass the test at all frequencies (up to the 8KHz limit), but that my hearing was at the threshold of her machine... most of the children that she measures are not that good. I guess the years of my misspent youth blasting the hell out of several large JBL systems didn't hurt me too much.:bouncy:


Widget

Titanium Dome
09-23-2006, 09:50 PM
As an add on to this topic, there's the problem of unilateral and asymmetrical hearing loss.

Unilateral hearing loss means that only one ear is affected.

Asymmetrical hearing loss means that the degree and/or configuration of the loss is different in each ear.

In my case, my right ear is the victim of unilateral hearing loss due to my brother's cute trick of throwing an M-80 into our outhouse when I was in there taking care of business. It exploded about 18 inches from my right ear, and the concussion took out a big chunk of hearing sensitivity that never returned.

This had the effect of ruining some spatial organization for me. For example, anytime I listen to headphones, the image is always shifted to the left, with the center at the 11:00 o'clock position in my head.

Thom
09-23-2006, 10:38 PM
When you say at 47 you can hear a 16 khz sinewave you don't say how loud because if you hear well at 16khz you as a 47 year old mail you are the exception. I remember years ago many relationships I wittnesed suffer do to a noisy flyback transformer on an otherwise perfect tv that a wife could hear and a husband couldn't. Just under 16k if memory serves me. (often it doesn,t) Omn the rock concert thing studies have shown thad we find objectionable are more harmeful than loud sounds we find pleasurable.

Steve Schell
09-24-2006, 12:50 AM
As recall, the frequency emitted by a TV flyback transformer is supposed to be 14,750Hz. This howl used to bother me with many sets, but I haven't heard it in several years now. When I first began messing with audio about 15 years ago I could hear up to about 17kHz., but now I hear nothing above 13.5kHz. when testing drivers with an audio generator. My upper hearing limit has decreased slowly but steadily over the years.

I think the averages of hearing acuity vs. age are made by sampling the public, most of whom have never learned to listen carefully. My hearing has been tested at several Piano Technicians Guild conventions and I always score well. That doggone Belltone hearing chart only extends to 8kHz. though. One audioologist mentioned that she found most piano technicians to have much better than average hearing for their ages. My theory is that we piano tuner types have developed the ability to isolate specific high frequencies at low levels from a complex sound field (required in piano tuning) and this gives us a perceptual advantage in these hearing tests. I would expect the same result with sesoned audiophiles.

One elderly horn enthusiast I know cannot hear any high frequencies; his limit may be only three or four kHz. When selecting crossover parts for his horn tweeters he uses midrange values, as he cannot hear any output from them using a more normal 5 or 7kHz. crossover point. He still greatly enjoys his constant fiddling with his system though, which I guess is the important thing.

Ian Mackenzie
09-24-2006, 01:57 AM
I was testing a 3145 crossover the other night and with the slot connected I ran a 15.6 Khertz tone to set the L pads.

I could sense the tone and to me up there and above is something you sense. Its a bit like very low bass, it doesn't play a key role in normal music but it can add spacial cues. The same applies to so called Uhf, the fundermentals are quite audible, the overtones are sensed.

http://www.listenhear.co.uk/general_acoustics.htm#Percussion



Sound is air in motion ó pushed, pulled, beaten, blown, plucked, talked, or sung into motion. Music is sound's highest achievement, a wonderfully varied mixture of patterned vibrations sent into the air by all kinds of instruments, from a cricket's hind legs to a massive pipe organ.

The frequencies of music, the various repetitions that make up the sound of instruments, are represented somewhat by the charts printed in equipment reviews in various audio/video magazines. But those charts look (and often are) so abstract that it's easy to forget that music is the point of it all. We are trying to remedy that here with the chart below, in which the frequency markings strung out along the bottom baseline are related to the frequency ranges shown above them of the various instruments in an orchestra.

If you've never had a chance to look at the way frequency response corresponds to the sound of instruments, you might want to note first that the divisions along the bottom line of our chart are anything but even. When most people first visualize the frequency range from 20 Hz to 20,000 Hz, they imagine a nice, linear, tape-measure span of measurement, on which the marked increments are as equal as the inch or centimeter markings on a ruler. But when you look at an actual response chart, the measures along the lateral line are definitely not an equal distance apart. In fact, the seemingly "small" span between 20Hz and 40 Hz is actually wider than the 6,000 Hz of difference between 10,000 and 16,000Hz. That's because the vibrations of the heavy-hitting bass instruments of music are ponderous and far apart, while the successively higher pitched instruments going up the scale vibrate faster and faster, and closer together. The frequency scale of music (and all sound) isn't linear but logarithmic ó which is probably why mathematics and music often seem to go so well together.

Our chart, courtesy of Stereo Review, is fun. It will give you an idea (if you didn't have one already) of where musical instruments lie across the audible frequency range. And there are surprises. Who would have thought, if they hadn't already known, that the bottom of the harp's range went below a double bass's, or that the contrabassoon aced them both? Or that the top of the oboe's range edged out the soprano voice? Or that the piccolo's top note topped the violin's? Or that the same harp that went so low also went right up near the top of the violin's and piccolo's range? Or that the guitar's top note was under 1,000 Hz? Look around the chart for a bit, and we'll go further after that.

While the chart begins to provide a grasp of where instruments lie across the frequency range, it has some critical omissions. The pipe organ, for instance,which goes down into subterranean regions, isn't represented. Neither is the bass drum, which has lots of energy below 50 Hz. Most critically, however, the chart portrays only the fundamental tones that instruments generate. What it doesn't show is the overtones, the harmonic frequencies, that give instruments their characteristic sound ó their timbre.

Harmonics are what let you tell instruments apart. Without them, similar instruments that played the same frequencies would sound the same. The harmonics are produced not by the notes, but by the method by which the musician sets those notes into motion and the materials used to produce the notes. The plucking of a string on a guitar, or the bowing of the string on a violin, is a lot different from the metallic resonance of a flute as air is blown through it by pursed lips, or the sound of a drum's membrane when it's struck by a hand or a drumstick. Everything counts ó the "attack" frequencies at the onset of notes (which are tremendously different from instrument to instrument), the "decay" frequencies at the end of those notes, the various resonances set in motion by the materials used for instruments, the differences between media excited from outside (like the string or the drum) and those excited from inside, like the flute and the trumpet. And besides upper harmonics, there are also subharmonics. The world of music is incredibly rich and varied.

We could go further, but what our chart does is give you a beginning taste of what "Hz" (cycles per second) really mean musically. There are charts that show the harmonics of instruments as well as the fundamentals, but we've never seen one that shows the varying harmonic intensities of all instruments in comparison with each other. (If you have, please let us know!) As we said earlier, the point is music. While we at PSB are intent on doing justice to the sound of crashing buses and dinosaur footfalls as well as flutes and violins and snare drums, it's the sound of music that keeps our juices flowing.

JBLnsince1959
09-24-2006, 06:45 AM
What I find interesting is that when I was young ( and many others), we could enjoy music almost no matter what speaker it came out of. Now don't get me wrong we all loved the JBL's because they were better and bought them. But as a teen and into the 20ies we could just enjoy the music and not worry

Now as we grow older it seems like we're trying to buy better cables, wires, amps, speakers, rework crossovers etc to get to the point where we were 30 years ago and just enjoy the music.

Sometimes I wonder how much of our love for the "older" JBL's is simply a search for our youth and how we heard then. Or how much "improving" the speakers is trying to makeup for our hearing loss.

JBL 4645
09-24-2006, 07:00 AM
Mr. Widget

Good topic, perhaps it should be made into a sticky thread.:applaud:

Iím 39 years old and Iím rather surprised I can hear a sine wave of up to 16.000KHz, Iíve leaned to lessen the sound level slightly over the years, has high frequency sounds can do irreversible damage top the tiny little hairs inside our ears!

All the literature that I have read over the years concerning this matter, I have absorbed, an 8 hours duration with a sound pressure level of 85db is deemed safe for human consumption, with irregular peaks up to 105db for short duration, films tend not to be overpowering, has there is a quite scenes and loud scenes, and demanding on the artist design of the soundtrack, some are quite pleasant, and the remaining few are Just Bloody Loud! And thatís when an audio limiter will save your hearing from being battered silly day in and day out.

Most of the time I use earplugs when going out down town, this is due to the high noise levels of traffic, buses peak around +90dba!

Oh one other thing, 16.000KHz has got a very short wavelength, of about, less than 1Ē.



Equal loudness contours and audiometry - Test your own hearing


http://www.phys.unsw.edu.au/~jw/hearing.html

JBL 4645
09-24-2006, 07:10 AM
I just checked my hearing range with the following link that I have provided, and given, that Iím in a cyber cafť at the present time, the NC background level is quite high.

I could make out 16.000KHz at Ė12db! If I was at home, it might have been far less.:)



Equal loudness contours and audiometry - Test your own hearing


http://www.phys.unsw.edu.au/~jw/hearing.html


Hearing loss, or hearing impairment
http://www.kidshealth.org/kid/health_problems/sight/hearing_impairment.html


Save Your Ears


http://www.athensmusician.net/archive/2004-11-01_hearing.php



William Shatner almost killed himself because of the incessant ringing in his ears called tinnitus

Don Mascali
09-24-2006, 07:20 AM
I just turned 60 and after years of:

USMC artillery Communications service
Motorcycles with straight pipes
Being an avid pistol shooter
NASCAR Winston Cup pit work
HVAC service on huge chillers
Mobile and club DJ work

I find it amazing that I can hear at all.
I can hear the compression with MP3 and some other formats and I can hear a sinewave sweep to 10K, but I can tell when my 2405s crossed at 9K are not working. I am carefull to use hearing protection when required and use a meter to check my listening level. (90 to 95 DBC normal and 105 for very brief periods.)
I would hate to loose more as I get older. It sure would be a waste of alot of fine JBL gear.:D

JBL 4645
09-24-2006, 07:25 AM
Don


Hello there

Tinnitus, now I have had this since I was young, never knew what it was, and it just comes and goes, yet I can still hear up to 16.000KHz, strange.

Activity / Decibels / Typical Physical Response
Rocket launching / 180 / Danger level Threshold of pain
Gunshot
Jet engine taking off / 140 / Danger level
Military jet
Air raid siren
Shotgun
Hydraulic press (3 m away) / 130 / Limited ability to hear amplified speech. Noise may cause pain. Can damage hearing after 3.75 minutes exposure per day
Car horn
Propeller aircraft
Air-raid siren / 120 / Can damage hearing after 7.5 minutes exposure per day
Sand-blasting
Squealing pigs
Inboard motorboatTypical night club
Un silenced motorcycle (7m away) / 110 / Maximum vocal effort. Can damage hearing after 30 minutes exposure per day
Amplified Rock Music / 110 -130 / Can damage hearing after 3.75 Ė 30 minutes exposure per day
Helicopter
Motorized/power mower / 105 / Can damage hearing after 1 hour exposure per day
Jet takeoff @ 500m
Train horn @ 30m
Diesel truck
Pneumatic drill/jackhammer / 100 / Can damage hearing after 2 hours exposure per day
Heavy truck @ 15m
Busy city street
passing motorcycle
Lawn mower
Loud shout
Screaming child / 90 / Very annoying. Can damage hearing after 8 hours exposure per day
Average factory
Electric shaver / 85 / Busy traffic intersection
Motorway construction site
Outboard motor
Alarm clock (with bell)
Freight train (15m away) / 80 / Annoying
Motorway traffic @ 15m
Roadside traffic
Train horn @ 500m
Vacuum cleaner
Mixer
electric sewing machine
Noisy restaurant
Conversation in a loud voice / 70 /
Telephone use difficult.
Washing machine/dishwasher / 65 /
Light car traffic @ 15m
City or commercial areas
Noisy office
Normal conversation
Clothes dryer
Background music / 60 / Intrusive.
Quiet office / 50 / Speech interference.
Refrigerator / 45 /
Quiet residential area
Kitchen/bathroom
Public library / 40 / Quiet .
Leaves rustling
Very soft music
Recording studio
Living/dining/bedroom / 30 / Very quiet.
Threshold of sound perception / 10 / Just audible.
Threshold of hearing / 0 / Not audible.

Rolf
09-24-2006, 07:30 AM
I agree with you guys. I just turned 54, an on my Denon technical cd I can hear 16000Hz. Maybe 17000Hz on my left ear, if I put my it very close to the 2405.

Widget. I can not understand that you do not hear a difference between a standard speaker wire. I use a speaker wire the costs about US$ 1000 here in Norway, and the difference is that "it gets more quite", and the instruments "do not disturb each other", if you know what I mean. I have the same experience with signal wires, but they also gives even more details to the music.

JBL 4645
09-24-2006, 07:32 AM
This is what I exactly use ďexactlyĒ even right at this very moment in time!

http://www.britishsnoring.co.uk/pim/web/42-front.gif

JBL 4645
09-24-2006, 07:36 AM
I agree with you guys. I just turned 54, an on my Denon technical cd I can hear 16000Hz. Maybe 17000Hz on my left ear, if I put my it very close to the 2405.

Widget. I can not understand that you do not hear a difference between a standard speaker wire. I use a speaker wire the costs about US$ 1000 here in Norway, and the difference is that "it gets more quite", and the instruments "do not disturb each other", if you know what I mean. I have the same experience with signal wires, but they also gives even more details to the music.

Rolf

Don’t use loudspeakers to do the test use the sound evaluator that I provide in the above posts, only use headphones, loudspeakers for this kind of test is crucial to use headphones, moving your head slightly in the room, will change the pitch of the frequency due to it’s wavelength!

Use headphones! :)

Also different frequencies can mask other frequencies, making it almost impossible to hear!

Rolf
09-24-2006, 07:48 AM
Rolf

Donít use loudspeakers to do the test use the sound evaluator that I provide in the above posts, only use headphones, loudspeakers for this kind of test is crucial to use headphones, moving your head slightly in the room, will change the pitch of the frequency due to itís wavelength!

Use headphones! :)

Also different frequencies can mask other frequencies, making it almost impossible to hear!

I have always used my speakers to find out how high I can hear. In the days of vinyl I used a Danish/German record "Hi-Fi Stereo Test", where the sine waves was on a direct cut record. I can remember at the age of about 22 I could hear 19000Hz from that record. After using it for a few times the frequencies on that record was removed from the record by the needle on the pickup. I bought a new one, and could hear it again.

For the last 15 years or so I have used the Denon test CD, and my hearing has gone down from 18000Hz to 16000Hz over that time.

I think this is a good indication of my hearing abilities. Or?

Bob Womack
09-24-2006, 08:29 AM
Typically females hear more acutely than males do. (But for some reason don't seem to get the audio bug like we do.) (-Snip-)WidgetI was recently asked by a friend why more women aren't involved in my field, audio engineering. What I've noticed over twenty-five years in recording is that women simply aren't interested in the field. I also knew that part of my job, repeatedly listening to sounds while I adjust them, drove my wife nuts. As part of answering my friend, I visited the website of WAM, the "Women's Audio Mission (http://www.womensaudiomission.org/)", an organization that attempts to overcome the disparity in representation of women in professional audio. Throughout their pages, there is a Flash feature that quotes "Quick Facts" about women in audio, such as representation statistics. There on the site they confirmed that women have better high-end hearing than men but they also confirmed that women have a lower tolerance for repeated sounds. Perhaps we have our answer right there.

Back to the main topic of the thread, hearing is a complex thing. We don't just loose our hearing. You see, the mind has auto-leveling gear that protects us from overload by closing down the amplifier when sounds get too loud and increases sensititvity when we need to hear a quiet sound better. This same gear compensates when transduction of part of the spectrum is inhibited by hearing loss by raising the gain in that frequency region. As you have probably witnessed, when you turn up the gain on your audio systems, as the gain comes up, so does the "self noise", the artifact of electronic activity in any electronic sound reproduction system. In the stereo it shows up as hiss. In analog days, you set your listening level by jacking up the background noise on either a tape or disk 'till you could hear it and then backing it off to a memorized level. These days, with digital sources and lower noise floors, you'd deafen yourself with the first note with that practice.

Anyway, as your hearing declines/or or is damaged, your mind psychoacoustically jacks up the level in the damaged area to compensate. Your ear's "self noise" rises as well, and is recognized as a problem called "tinnitus" or ringing of the ears. When narrow-band sound is played in the presence of a broad-band sound of near intensity, the narrow-band sound is "masked" by the blanket of the broad-band sound, and the mind has a hard time distinguishing it. This effect causes it to be hard to extract a the foreground sound from the background as you age.

Meanwhile, you have some individuals who, despite presbycusis, seem to be able to discern material in ranges where they have limited hearing. I guess I'm not surprised. We don't typically loose all of our hearing in those ranges. We do become severely impared and the mind compensates, causing an increase in the self noise that further complicates hearing. However, some people, possibly due to training and practice before loss, appear to have the ability to "steer" their senses to somehow detect more than expected in those ranges.

I read an article recounting the experiences of amous console designer Rupert Nev concerning the hearing of then-middle-aged engineer Geoff Emerick in the ultrasonic range. Never was called to troubleshoot an analog console that just didn't sound right by the rather famous recording engineer. Neve put the scopes on the input modules of the console and found no differences in the audible range between known-good modules and the problem modules. He then swept up into the ranges above. He found no problems until he reached the 54khz range, where he discovered a little peak in the response. When he investigated the circuit, he discovered that the problem modules were a later "mark" of the same circuit. In the later "mark", one component, a filter cap in the transformered input affecting only the frequencies above 50k, had been omitted as superfluous because it didn't affect the audible range. Neve supplied caps and put the modules on the scopes again, observing that their response was then indentical to the other channels through 100k. He then conducted a blind listening test with his client engineer with known-good, "fixed", and identified "bad-sounding" moduless. His client was easily able to identifty the bad sounding modules, but the known-good and "fixed" modules were identified as identical. According to every criterion measurable by Neve, the only characteristic that had changed was the ripple at 54khz.

Does that mean Emerick could hear 54khz? I don't know. I doubt it. It does mean that he could hear the difference produced by an alteration that only affected the response in that frequency of the circuit. Think on.

Bob

JBL 4645
09-24-2006, 09:09 AM
Rolf

I wonder if that is the same Denon CD check disc that I also happen to have, is it the one with a picture of a Denon amp on the front cover? :)

Mr. Widget
09-24-2006, 10:24 AM
My upper hearing limit has decreased slowly but steadily over the years.I think that is simply one of those inconvenient truths:) as we get older we loose a little bit of our hearing every few years... luckily we can still enjoy our love of music and passion for audio.



I can hear the compression with MP3 and some other formats and I can hear a sinewave sweep to 10K, but I can tell when my 2405s crossed at 9K are not working.That correlates exactly what I have seen with the two other forum members that I mentioned. I find it fascinating. It is possible that Steve's suggestion that we as audiophiles (Or whatever term you choose to use) have trained ourselves to listen more closely than the general public... but I believe there are aspects of complex musical signals that allows us to hear significantly higher musical tones than pure sinewaves... in fact it may be possible for younger ears to actually perceive complex signals well above 20KHz. This is certainly speculation, but if the early tests done to establish the audio frequency range of 20Hz to 20KHz were done with pure sine waves, it may not entirely correlate with our actual hearing.


Widget

Mr. Widget
09-24-2006, 10:30 AM
Widget. I can not understand that you do not hear a difference between a standard speaker wire.This is an entirely different subject. The simple fact is, I have listened to several high end speaker cables... I currently have some massive Cardas cables in my system. (Four runs for the mids and highs of my tri-amped system. The cables are on loan from a friend.) I have listened for weeks to these cables and cannot hear a difference when I put my 12ga basic wire back in the system. I have also tried Kimber and others... the same result. I did try one of the cables with a network on it... I did hear a difference, the bass bloomed and bugged the hell out of me.


Widget

JBL 4645
09-24-2006, 11:17 AM
I would put it like this; we lose a bit of our frequency response and range on hearing every few years, man that sucks!:(

Thom
09-24-2006, 11:23 AM
I'm sure glad that hearing is the only thing that goes

Titanium Dome
09-24-2006, 01:28 PM
I'm sure glad that hearing is the only thing that goes

:rotfl: I'd suggest you not look down.

Don Mascali
09-24-2006, 01:51 PM
:rotfl: I'd suggest you not look down.

HAH! a little Testosterone injected BiWeekly takes care of that.:applaud:

Gary L
09-24-2006, 02:01 PM
Thank you Mr. Widget, Very interesting thread.

I spent 4 years in USN Aviation and 27 years as a weapons instructor and on the fireing line. I know my hearing is defective and suspected many of us encounter some losses along the way.

This gets back to my original thoughts about where speakers tend to Roll Off.

What difference does it make if your speakers tend to roll off at frequencies above or below what you can hear?
Seems to me many of us are simply chasing shadows and searching for the very best when in fact, we can't hear it anyway.

I applaud those of us who are "Golden Eared" but the facts above just prove my thoughts. I am 54 and adding a high end tweeter to cover the frequencies above where I can hear is a total waste of time and effort for me and for many others.
I am not saying don't do it, just don't expect to get much audible improvment for your efforts. Some things simply can't be gotten back and no ammount of upgrade or spent money will change the facts.

Gary

edgewound
09-24-2006, 02:02 PM
This is an entirely different subject. The simple fact is, I have listened to several high end speaker cables... I currently have some massive Cardas cables in my system. (Four runs for the mids and highs of my tri-amped system. The cables are on loan from a friend.) I have listened for weeks to these cables and cannot hear a difference when I put my 12ga basic wire back in the system. I have also tried Kimber and others... the same result. I did try one of the cables with a network on it... I did hear a difference, the bass bloomed and bugged the hell out of me.


Widget

Well that's certainly something we can agree on...and so do physicists from Cal-Tech.

George Cardas' factory used to be in the same industrial complex as my shop is now.

I spoke to him at the CES show about 15 years ago and commented on the beautiful construction of his products. With all the different geometry in his cables that time-align the lows, mids and highs, and the solid connectors at each end of the cable attached to the solid connectors at the amp and speakers...I asked him. "how do the electrons know which conductor to travel through, and why does your cable make a difference?"

He turned around and spoke to someone else. That explained it all.:bs:

I've had a couple physics professor's from Cal-Tech as customers. I asked them from a physics standpoint about the merits of all this ultra expensive cable technology. They said the most important element is to have the highest quality, heaviest guage copper in the shortest length as practical...at audio frequencies. Video frequencies are somewhat different, but not to justify spending thousands of dollars on something that cost pennies to manufacture....unless spending more money to impress your buddies is important....More:bs:

Don Mascali
09-24-2006, 02:11 PM
This gets back to my original thoughts about where speakers tend to Roll Off.

What difference does it make if your speakers tend to roll off at frequencies above or below what you can hear?
Seems to me many of us are simply chasing shadows and searching for the very best when in fact, we can't hear it anyway.

I applaud those of us who are "Golden Eared" but the facts above just prove my thoughts. I am 54 and adding a high end tweeter to cover the frequencies above where I can hear is a total waste of time and effort for me and for many others.
I am not saying don't do it, just don't expect to get much audible improvment for your efforts. Some things simply can't be gotten back and no ammount of upgrade or spent money will change the facts.

Gary

Please see my post #9 and Widgets reply in #17
Idon't know what but something is going on up there above 10K for me. If I turn off my tweeters it sounds like crap.

Thom
09-24-2006, 02:14 PM
Usually,before you totally lose lose the ability to hear a frequency, it becomes attenuated. I suggest equalizing for your hearing loss, and if that doesn't sound as good to someone else, well, that is probably why you didn't mess with their system!

Zilch
09-24-2006, 03:26 PM
I'm moving this particularly relevant ('cause I wrote it :p ) post over from the other thread. I think it would be a very BAD idea from the perspective of hearing protection to boost the high frequencies that we are less able to hear and thereby increase the likelihood of doing more damage and/or accelerating the decline, particularly if we routinely listen at substantial SPL.

I consider anything above 90 dBA "substantial," and so does the NIOSH standard. I try to stay under 85 dBC, in practice; the RS SPL meter is always close at hand.

The fundamental question was whether the rolled-off high frequency response of many "Vintage" systems is even an issue if we can't hear the VHF anyway:


A more serious question to me and possibly others is, As we age, Where does the human ear rool off?If we accept the premise that our hearing "rolls off" as opposed to "shuts off" at a certain frequency, and that frequency gets lower with age, then it's virtually a given that having the high frequency reproduction NOT roll off also is essential to maximum enjoyment of the musical content as we age.

One look at an RTA in action with music playing is sufficient to convince anyone that the content is there.

As I recall, the audiologists' ISO standard test method and audiogram charts stop at 8 kHz....

Mr. Widget
09-24-2006, 03:41 PM
I think it is most likely that we do have a roll off as opposed to shut off, but this roll off is likely fairly steep...

As for boosting the highs beyond what we can actually hear, I'd guess that if you can not effectively hear 15KHz very well and you compensate for this by jacking it up 10 or more dB, you are probably accelerating your hearing loss when you have the portion of the spectrum that you do hear turned up loudly.



One look at an RTA in action with music playing is sufficient to convince anyone that the content is there.I am not sure I understand this portion of your post.


Widget

Zilch
09-24-2006, 03:56 PM
I am not sure I understand this portion of your post.Well, it almost goes without saying, but I'm saying it anyway for those who might never have seen it, and those who deny its import and "never miss" it:

There is substantial sonic content present in the 10 kHz to 20 kHz octave in virtually all program material.

We're also supposed to be soon hearing some kind of case being made by JBL for the next octave above that, as well.... :p

Mr. Widget
09-24-2006, 03:59 PM
Well, it almost goes without saying, but I'm saying it anyway for those who might never have seen it, and those who deny its import and "never miss" it:

There is substantial sonic content present in the 10 kHz to 20 kHz octave in virtually all program material....Oh... I didn't realize there was any controversy there.

There is also content above that... if you are using analog or high def equipment. There is some debate about the validity of reproducing that content. Based on those that only hear sinewaves to 10KHz and yet hear the effects of tweeters above that frequency, I am more inclined than ever to accept the possibility that having drivers respond to beyond 20KHz is useful.


Widget

Phil H
09-24-2006, 04:17 PM
I was curious about my own hearing so I just did a quick search online. I found an interesting site that will enable a person to find there own equal loudness curve (30hz-16k). I had to turn up the volume on my computer to hear the 16khz. I can't hear the 30hz, but It may be the cheap speakers for my computer. I don't have headphones, so tonight I will try when there is less background noise.
http://www.phys.unsw.edu.au/~jw/hearing.html

Zilch
09-24-2006, 05:12 PM
Thanks, Phil!

I'll dig out the headphones tonight....

:thmbsup:

Mr. Widget
09-24-2006, 05:33 PM
I was curious about my own hearing...For this test to be really useful, you need to have a calibrated computer playback system... I'd bet most computer systems are far from accurate.

It is a really cool link though.:thmbsup:


Widget

Titanium Dome
09-24-2006, 05:37 PM
(snip)
http://www.phys.unsw.edu.au/~jw/hearing.html


Great, Phil! Thanks!

I tried it and got the following results with Sennheiser HD500 headphones. For the 12kHz and 16kHz tones, I only heard them in my left ear, thanks to my brother's jackass trick when we were kids. (See my post #2 above.)

Phil H
09-24-2006, 09:52 PM
Mr. Widget,
I didn't think it would be very accurate (especially with my soundcard and speakers). But, it gives a general idea. I was happy to hear the highest frequency. For many years, I took my hearing for granted and worked around loud equipment without using hearing protection.

Mr. Widget
09-24-2006, 11:25 PM
I didn't mean it as a criticism, but rather to remind us that your cranking up 16KHz is quite possibly a combination of your actual hearing and the playback chain. With my crappy little USB headset, I cannot hear anything at 30Hz or 16KHz. It does seem that from looking at both your post and TiDome's, that the Fletcher Munson curve is roughly in evidence.


Widget

Rolf
09-25-2006, 12:14 AM
Rolf

I wonder if that is the same Denon CD check disc that I also happen to have, is it the one with a picture of a Denon amp on the front cover? :)

No it's not. Anyway not the cover. The CD is a Denon PCM Digital Recording from 1984 with the number 38C39-7149 printed on it.

Here are the cover:

Rolf
09-25-2006, 12:29 AM
I spoke to him at the CES show about 15 years ago and commented on the beautiful construction of his products. With all the different geometry in his cables that time-align the lows, mids and highs, and the solid connectors at each end of the cable attached to the solid connectors at the amp and speakers...I asked him. "how do the electrons know which conductor to travel through, and why does your cable make a difference?"

He turned around and spoke to someone else. That explained it all.:bs:



Well, that says a lot. Maybe my way of explaining this not the best way, but here it goes: I guess you don't know that a 20Hz tone travels better and faster in a thick wire than in a thin one. It's a bit like trying to move 10.000 gallons of water the fastest way. Witch pipe do you think get rid of the water first, a 1" or a 10"? It's also like using 10.000W of electric power needs a thicker cable than if you use only 100W.

Engineers is also agreed in that different frequencies likes different thickness of wire to get out of the other end of a cable without loosing to much of the signal that was on the input side.

If such a cable sounds better to our ears? Well that is another story, and is highly subjective.

JBL 4645
09-26-2006, 04:14 AM
I'm sure glad that hearing is the only thing that goes

Thom

Wrong! The same also applies to are eyesight, never point a telescope at the sun it blind you! :(

JBL 4645
09-26-2006, 04:17 AM
Rolf

I see I havenít got that version, Iíve made a mental picture of it with that graphic design work, Iíll keep an eye out for it thanks.:)

JBL 4645
09-26-2006, 04:21 AM
Well, that says a lot. Maybe my way of explaining this not the best way, but here it goes: I guess you don't know that a 20Hz tone travels better and faster in a thick wire than in a thin one. It's a bit like trying to move 10.000 gallons of water the fastest way. Witch pipe do you think get rid of the water first, a 1" or a 10"? It's also like using 10.000W of electric power needs a thicker cable than if you use only 100W.

Engineers is also agreed in that different frequencies likes different thickness of wire to get out of the other end of a cable without loosing to much of the signal that was on the input side.

If such a cable sounds better to our ears? Well that is another story, and is highly subjective.

Rolf

Yeah I think I understand what youíre saying there!

So if I where to replace the wiring on my passive X-over for the JBL control 5 three-screen, by re-wiring it, with a more thicker wire, high frequencies will translate a bit better, is that what you saying? :)

JBL 4645
09-26-2006, 04:38 AM
Not sure if this will upload!

Phil

Hay, how did you place the hearing graph on the screen? How did you upload it, thanks?

Phil H
09-26-2006, 09:22 AM
JBL 4645,
I took the quick and easy route; T-dome did a better job. I copied the active window to the clipboard by pressing Alt and Print Screen at the same time. Then, I pasted it into Paint and saved the file on my system as a jpeg. I uploaded this like any other picture. The active window can not be full size to do this; the file-size (and image size) would be too big for the forum.

JBL 4645
09-27-2006, 01:33 AM
Phil

You know you’re absolutely right I now remember some showing me this technique a short while ago, I’ll take the test again and follow what you said and hopeful it will upload! I’ll put the graph in the “edit mode” and resize the image to look reasonable.

Thanks mate.:)

Rolf
09-27-2006, 11:35 PM
Rolf

Yeah I think I understand what youíre saying there!

So if I where to replace the wiring on my passive X-over for the JBL control 5 three-screen, by re-wiring it, with a more thicker wire, high frequencies will translate a bit better, is that what you saying? :)


Well, actually not quite. It is the low frequency that needs a thick ("fat") cable. The mids and nights are fine with a rather thin cable. That is why many speaker cable producers use different thickness of the Cordell's in the cable. The thick massive Cordell's will transport the deep frequencies, as they have very high current, and uses the most power of the amp. The mids and heights don't use so much power to do the same thing, so the Cordell's don't have to be so massive.

Try using the thinnest cable you have, connect it to the power outlet in you house and to a source that uses 40W, and all is fine. Connect it to a source that uses +2000W and the cable will get so hot it will burn of. This is why you need a thicker wire in your house on a 20 ampere than on a 10 ampere. (You probably know this)

In my bi-amp setup (with the 4343) I use the same cables for the woofer and for the rest. Inside the cabinet I use different kind of cables from the network to the different drivers. The cable to the woofer goes directly to the woofer.

In my ears this is a great improvement, and I have NEVER changed a cable or unit in my life if I could not hear an improvement.

Hope this explain my views.

JBL 4645
09-29-2006, 12:49 PM
Rolf

Well that does make sense to think I was close to doing it. So the thin cable that goes from the JBL Control 5 passive X over is way to thin, would modifying it with a thicker cable make much difference, and getting the thick cable to fit into the hole on the passive networks X over PCB is not going to an easy task, without damaging the PCB, buy drilling into the hole steadily and making sure not to do damage to the circuit track!

Any, thoughts if this is beneficial to making the sound in the bass mid clearer to hear?

Anyway this is kinder drifting of the topic here, but seeing some brought the matter up Iíll make it short, maybe a new thread on this particular matter should be started here.

I know the benefits of an active X over unit over a passive X over, just wondering about the modification, will it be waste time or will it be productive!?:)

Rolf
09-29-2006, 02:15 PM
Rolf

Well that does make sense to think I was close to doing it. So the thin cable that goes from the JBL Control 5 passive X over is way to thin, would modifying it with a thicker cable make much difference, and getting the thick cable to fit into the hole on the passive networks X over PCB is not going to an easy task, without damaging the PCB, buy drilling into the hole steadily and making sure not to do damage to the circuit track!

Any, thoughts if this is beneficial to making the sound in the bass mid clearer to hear?

Anyway this is kinder drifting of the topic here, but seeing some brought the matter up Iíll make it short, maybe a new thread on this particular matter should be started here.

I know the benefits of an active X over unit over a passive X over, just wondering about the modification, will it be waste time or will it be productive!?:)





Last post of this issue here. I send you a pm.

JBL 4645. YES, it will make a great difference changing the cables. To change the cables to your woofer from the original network can be "a pain in the ass" to do, and you have to figure out if it is possible without doing any damage. As you know, I just connected the speaker wire directly from the amp to the terminals on the woofer.

You use Control 5 speakers ... right? I don't know them, and do not know how the possibilities are regarding cable modifications.

The cabling for the rest of the components in my speakers are not optimal, as the bi-amp switch is and l-pads are still in function, but I have changed the wires where ever possible and used pure silver cables. Using pure silver is not easy, as you have to get them made totally free from air. If not they will corrode, and finally be useless. I would recommend you to use copper if you do not have some professionals to do it. The best in my opinion will be to build new networks where cabling is considered from the start.

My plan is to have Guido build totally new networks, bypassing the bi-amp switch and the l-pads. I know this will improve the sound a lot. But so far I have not done it. (It will be done in the not so far future).

Rudy Kleimann
09-29-2006, 06:59 PM
I must say, I was stunned when I read your post. I think you're right in everything you've posted. Hard to believe, but I do believe we can hear much higher than 20KHz. The brain and sensory organs (still the most powerful "computer" in existence IMHO) can certainly compensate for frequency response abberations from hearing loss/damage over time, with the inherent limitations of "hearing sytem self-noise" as you put it.

Reminds me of an article I read about harmonics of musical instruments, particularly wind instruments and especially the trumpet (which I play) that produce harmonics (aka overtones) up to and exceeding 100KHz. It suggests that we humans can readily percieve the presence (or absence) of these UUHF harmonics. Wish I had the link to it handy... I'll have to look for it.



I was recently asked by a friend why more women aren't involved in my field, audio engineering. What I've noticed over twenty-five years in recording is that women simply aren't interested in the field. I also knew that part of my job, repeatedly listening to sounds while I adjust them, drove my wife nuts. As part of answering my friend, I visited the website of WAM, the "Women's Audio Mission (http://www.womensaudiomission.org/)", an organization that attempts to overcome the disparity in representation of women in professional audio. Throughout their pages, there is a Flash feature that quotes "Quick Facts" about women in audio, such as representation statistics. There on the site they confirmed that women have better high-end hearing than men but they also confirmed that women have a lower tolerance for repeated sounds. Perhaps we have our answer right there.

Back to the main topic of the thread, hearing is a complex thing. We don't just loose our hearing. You see, the mind has auto-leveling gear that protects us from overload by closing down the amplifier when sounds get too loud and increases sensititvity when we need to hear a quiet sound better. This same gear compensates when transduction of part of the spectrum is inhibited by hearing loss by raising the gain in that frequency region. As you have probably witnessed, when you turn up the gain on your audio systems, as the gain comes up, so does the "self noise", the artifact of electronic activity in any electronic sound reproduction system. In the stereo it shows up as hiss. In analog days, you set your listening level by jacking up the background noise on either a tape or disk 'till you could hear it and then backing it off to a memorized level. These days, with digital sources and lower noise floors, you'd deafen yourself with the first note with that practice.

Anyway, as your hearing declines/or or is damaged, your mind psychoacoustically jacks up the level in the damaged area to compensate. Your ear's "self noise" rises as well, and is recognized as a problem called "tinnitus" or ringing of the ears. When narrow-band sound is played in the presence of a broad-band sound of near intensity, the narrow-band sound is "masked" by the blanket of the broad-band sound, and the mind has a hard time distinguishing it. This effect causes it to be hard to extract a the foreground sound from the background as you age.

Meanwhile, you have some individuals who, despite presbycusis, seem to be able to discern material in ranges where they have limited hearing. I guess I'm not surprised. We don't typically loose all of our hearing in those ranges. We do become severely impared and the mind compensates, causing an increase in the self noise that further complicates hearing. However, some people, possibly due to training and practice before loss, appear to have the ability to "steer" their senses to somehow detect more than expected in those ranges.

I read an article recounting the experiences of amous console designer Rupert Nev concerning the hearing of then-middle-aged engineer Geoff Emerick in the ultrasonic range. Never was called to troubleshoot an analog console that just didn't sound right by the rather famous recording engineer. Neve put the scopes on the input modules of the console and found no differences in the audible range between known-good modules and the problem modules. He then swept up into the ranges above. He found no problems until he reached the 54khz range, where he discovered a little peak in the response. When he investigated the circuit, he discovered that the problem modules were a later "mark" of the same circuit. In the later "mark", one component, a filter cap in the transformered input affecting only the frequencies above 50k, had been omitted as superfluous because it didn't affect the audible range. Neve supplied caps and put the modules on the scopes again, observing that their response was then indentical to the other channels through 100k. He then conducted a blind listening test with his client engineer with known-good, "fixed", and identified "bad-sounding" moduless. His client was easily able to identifty the bad sounding modules, but the known-good and "fixed" modules were identified as identical. According to every criterion measurable by Neve, the only characteristic that had changed was the ripple at 54khz.

Does that mean Emerick could hear 54khz? I don't know. I doubt it. It does mean that he could hear the difference produced by an alteration that only affected the response in that frequency of the circuit. Think on.

Bob

Rudy Kleimann
09-29-2006, 07:06 PM
I absolutely agree about training yourself to be able to hear better/more than others. Music has a way of doing that:). Good playback (on JBL's, for instance) is another way:D . Playing a musical instrument, well... :bouncy:


And the NTSC standard of 525 scanned lines per frame multiplied by 30 frames per second = 15,750HZ emitted from the flyback transformer and related circuitry in your TV. Happily, we can attribute our inability to hear this as much as we get older to the fact that TV components and circuits have become better in design and manufacture and simply are much quieter than Mom & Dad's TV was when we were little. ;)


As recall, the frequency emitted by a TV flyback transformer is supposed to be 14,750Hz. This howl used to bother me with many sets, but I haven't heard it in several years now. When I first began messing with audio about 15 years ago I could hear up to about 17kHz., but now I hear nothing above 13.5kHz. when testing drivers with an audio generator. My upper hearing limit has decreased slowly but steadily over the years.

I think the averages of hearing acuity vs. age are made by sampling the public, most of whom have never learned to listen carefully. My hearing has been tested at several Piano Technicians Guild conventions and I always score well. That doggone Belltone hearing chart only extends to 8kHz. though. One audioologist mentioned that she found most piano technicians to have much better than average hearing for their ages. My theory is that we piano tuner types have developed the ability to isolate specific high frequencies at low levels from a complex sound field (required in piano tuning) and this gives us a perceptual advantage in these hearing tests. I would expect the same result with sesoned audiophiles.

One elderly horn enthusiast I know cannot hear any high frequencies; his limit may be only three or four kHz. When selecting crossover parts for his horn tweeters he uses midrange values, as he cannot hear any output from them using a more normal 5 or 7kHz. crossover point. He still greatly enjoys his constant fiddling with his system though, which I guess is the important thing.

JBL 4645
09-29-2006, 09:43 PM
I can hear the high frequency from my SONY KX 27-PS 1, sweet.:)

Whaleís frequency response
http://www.birds.cornell.edu/brp/SoundsBlueWhale.html (http://www.birds.cornell.edu/brp/SoundsBlueWhale.html)

JBL 4645
09-29-2006, 09:46 PM
WOW those whales’ sounds where beautiful!:)


Rudy

Well the whale sounded like a trumpet in the distance in the second recoding on this link. Sorry Horn!


Whale’s frequency response
http://www.birds.cornell.edu/brp/SoundsBlueWhale.html (http://www.birds.cornell.edu/brp/SoundsBlueWhale.html)

Akira
10-02-2006, 09:33 AM
Just because a dog can hear higher frequencies than us does not mean they can hear better. Anyone with a canine friend can conduct simple tests to verify this. Likewise, a dog can possess amazing hearing when their brains are fixated on a sound signature.

Regrettably, I have severe hearing loss from 30 years of working in the sound industry--a 30db dip in response @ 4K. My response returns to normal (age compensated) within 1/3 octave of each side 4K. (3K-5K) I also have slight tinitus which I can only hear in extremely quiet circumstances. This is a condition typical of many FOH and recording engineers who have spent decades in the trenches, as the hairs in the cochlea lie down, or are "blown down." (Sounds like a tired speaker) Yet, 4K is the one frequency that I still find too loud.

HOWEVER, well known albums sound the same to me as they always did. I can produce finer recordings now than ever before. I can hear nuances now that I could not detect even when I was younger with fresh ears. The only detectable impediment is my "critical hearing window" is much shorter now--the point in time where my ears can make accurate 'mix' judgements. Loud sounds will close down my hearing much quicker.

I attribute my ability to still work and enjoy sound and music to "learned hearing and sonic education."

So my JBL friends....the good times will still continue for a while.

MJC
05-04-2007, 06:22 PM
I did the curve test, using a pair of wall mounted L212s set to the sides of this monitor.
The curve pretty much paralleled a hearing test I had done at Costco two months ago. It stayed flat until it dropped 15db @ 4k and then drops off another 15db @ 6k and then way off @ 8k. 12k,16k I couldn't hear at all.
With headphones it might improve a bit.
Considering I'm 59 and working construction for 36 years, plus firing most military weapons known to NA in the late '60s and having a demolitions MOS, to boot, my hearing is still fairly good. In fact the tester at Costco thought my hearing was very good, considering it all.
I do compensate my setups by boosting the eq a bit on the upper and lower ends.

JBL 4645
09-02-2007, 05:08 PM
Tinnitus is driving me crazy:banghead: its takes a good consternated use of orange juice with vitamin c and a few days break from the sound system and real world loud traffic! Iíve had tinnitus sine I was young but I feel its getting worse maybe?

I just stuck the headphones on to run the hearing test and thou there is noise of the headphones or rather the sound card is at fault because 16KHz sounds like a different frequency entirely due to the computers poor sound card, 12KHz dropping down to 30Hz seams ok, but the tones on the lower end degrades due to the poor headphones. I do have a better pair but the phone jack need repairing.

So this was what I could make out.

boputnam
09-02-2007, 08:08 PM
...12KHz dropping down to 30Hz...You mean -33dB, right?

Actually that sensitivity curve is not so bad. You are very and nearly equally-sensitive to the range 60Hz to 3kHz, above which there is some loss of hearing - could be age related. Taking into account soundcard and headphone related issues, that is a pretty good curve...

JBL 4645
09-03-2007, 08:59 AM
You mean -33dB, right?

Actually that sensitivity curve is not so bad. You are very and nearly equally-sensitive to the range 60Hz to 3kHz, above which there is some loss of hearing - could be age related. Taking into account soundcard and headphone related issues, that is a pretty good curve...

boputnam

Yeah but the tinnitus is driving me to the point of depression man. If I can find a way to fix the headphones on the (Sennheiser SH 2200) without breaking them you see Iíve been fairly careful with these since 2003 until last year when the phone jack that plugs into them got knocked and dislodged the (PCB) one of the pins has come undone and needs soldering.

Yeah I know I should leave this matter for a different thread.

Also thereís the computers background noise level which needs addressing nothing too expensive just a few minor alterations thatís all.

Besides having a fairly good listening curve at present that is because anything can happen, I could walk down the road and then all of a sudden thereís and loud yet uncontrolled explosion that would do damage?

Having just said that Iíve placed my ear plugs in my black trousers I fear I might have just jinxed myself.:(

Iíve taken at least a two days break from music and the movies I guess I havenít enough vitamin c.:D

JBL 4645
09-03-2007, 09:11 AM
Adding a little further to this I had a fine ear on the CB radio many years ago with single sideband modes to do long distance talking. And while I was listening for the frequency tones (sine waves) short pluses I was kinder nodding to, myself that tone is too audible under the room conductions. So I decrease the level until its just audible in the back of the box or the headphones.

Slight pc noise background level though headphones
Pc computer fan noise
So having to concentrate on the tone and having hearing the tones before my memory is telling me what tone to listen out for.

I really should make an appointment to see a professional just to be certain.

JBL 4645
09-03-2007, 09:24 AM
Iíve gone back though the thread and saved Phil H and the Dome to the pc as well as mine from last night to see what differences there are between the three test tone results.

But since each one of us are using different computers different headphones or loudspeakers and what level was the pc volume set to? Thereís no way of telling, the volume on my pc last night was set to full, but thatís when I can hear what appears to be computer noise in the background oh well nothings perfect.

From top to bottom
Phil H
Dome
JBL 4645

Fred Sanford
09-03-2007, 10:28 AM
Add this one if you like, for what it's worth- Dell laptop, AKG K141 headphones, washing machine & dryer audible in the background throughout (yeah, not very helpful, probably explains the gain needed for the lows). 42 yr. old male, playing music/modding audio systems/running sound systems for ~26 years.

Always hated the sound of CRT TVs, monitors & projectors, I could often even hear them from neighboring rooms through walls.

JBL 4645
09-03-2007, 10:54 AM
Fred

Run the test in the night time when all the ambient background noise levels drop down. And with the washing machine off! By the way do you hear any computer noise on the headphones before playing any sound program material?

ChopsMX5
09-03-2007, 01:11 PM
Here's mine, just for poohs and giggles.

No ambient noise in the room/house
Two 120mm fans slowly runnig in my PC, making virtually no noise
AMD Athlon 3400+ 64 bit processor
Microsoft XP Pro x64 Ed
SoundBlaster Audigy2 Platinum
Little Dot Micro+ Headphone Amp
Grado SR-325 HeadphonesI'm a 32 year old male and have been a little harder on my ears thant I probably should have over the years, constantly going to concerts, night clubs, having loud car stereos and home systems for the past 14 years.

As a side note, I ran the test with and without the Little Dot head-amp and the results were the same. I also ran the test through a pair of Sony MDR-7506 headphones (with/without amp) and through my bedroom stereo with DIY 3-way tower speakers I built 11 years ago, and all gave similar results. I also tested each ear separately with both headphones, with matching results.

http://charlest.zenfolio.com/img/v2/p821764712.jpg

Fred Sanford
09-03-2007, 03:04 PM
Fred

Run the test in the night time when all the ambient background noise levels drop down. And with the washing machine off! By the way do you hear any computer noise on the headphones before playing any sound program material?

Not sure what you mean by computer noise. I wouldn't hear the fan or the drive spinning, and didn't hear any data chatter.

Ambient noise levels? I've currently got about 4 bozos firing off shotguns in the field in front of my house. Don't think that calms down after dark, either. Who'd have thought I'd hear more gunshots here than in NYC...

I could hook the laptop up to the 4333As tomorrow...

je

JSF13
09-03-2007, 05:24 PM
Ran a graph for myself. Don't know how to copy it here but I could sure see why I have to crank my mids down.

JBL 4645
09-03-2007, 06:27 PM
Ran a graph for myself. Don't know how to copy it here but I could sure see why I have to crank my mids down.

JSF13

Look at the keyboard and look for (Print Screen) its above delete Insert buttons.

Press it and then look for (Paint) in the start button section once youíve found it right hand click and paste.

JBL 4645
09-03-2007, 06:37 PM
Youíll see Image select decrease the size by inputting even numbers in the horizontal and vertical save the image under Jpeg, then look though youíre pictures folder select the picture by using the Lansing heritage sites own picture upload. Press open it should take a few seconds upload.

JSF13
09-03-2007, 08:27 PM
Must be doing something wrong because I get an error message that "paint can't read this file"

Anyway here are the numbers,low to high.No numbers for 12 or 16 as I can't hear them.

-12,-21,-24,-27,-30,-36,-39,-42,-42,-42,-36,-33,-24,-24,-21,-3,-6 -,-.

cvengr
02-15-2008, 02:54 PM
This topic has caught my attention recently for a number of reasons.

Firstly, there are a number of manufacturers of speaker/transducer systems which now use ultrasonic systems to project sound over large distances, then the air or medium transmitting the sound attenuates and produces apparently three subharmonics, of which at least one is in the audible range at further distances.

This was recently used in a commercial billboard advertisement in or near SOHO with an advertisement for Paranormal State, and A&E series on the paranormal. http://www.holosonics.com/PR_AE.htm

I also understand that many recent developments in hearing aids don't so much amplify the sound patterns entering the ear, as much as redirect the sound with ultrasonics so that audible frequencies are heard further down the ear canal. In effect, much of the attenuation of the sound is due to hair growth within the ear which filters out audible frequencies, so the solution has been to refocus the sound waves to constructively interfere and become audible simply further down the ear canal past internal blockages.

I've noticed something similarly with recent specifications on transducers. Many tweeters today are being produced which range in output far beyond 20,000 Hz (generally regarded as the upper limit of audible sound).

I was wondering if anybody in this forum had been involved in the design and production of these higher ranging devices. Were they designed to operate at the higher frequencies or was that simply a collateral benefit in deigning the devices to meet lower frequency parameters?


I must say, I was stunned when I read your post. I think you're right in everything you've posted. Hard to believe, but I do believe we can hear much higher than 20KHz. The brain and sensory organs (still the most powerful "computer" in existence IMHO) can certainly compensate for frequency response abberations from hearing loss/damage over time, with the inherent limitations of "hearing sytem self-noise" as you put it.